Author Topic: Headline: Hondaman rebuilds his old friend - FOUND GOOD OIL!  (Read 116490 times)

0 Members and 3 Guests are viewing this topic.

Offline lwahples

  • Enthusiast
  • **
  • Posts: 179
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #225 on: September 07, 2013, 03:03:53 PM »
Dang! That sure doesn't sound like any fun at all.Glad to hear you are on the mend. I'm really enjoying all your knowledge on this build.

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #226 on: September 07, 2013, 09:07:14 PM »
Installed the head seals after the retorque today. Pix below: with the crop of too-thin head seals we keep seeing, here is a way you can check the ones you got in your gasket kit (or elsewhere, like PartsNmore or CB750Supply, etc.).

First, check the step depth of the head hole. Then, check the thickness of your seal. You need at LEAST .030" compression, .040" is better. The too-thin ones are only about .005" thicker, which won't seal when the head heats up and the hole becomes deeper.

Then I spread the non-hardening sealer around the edges of the seals (messy!) and twist them into their holes to seat them and their goo. I also spread the bead around their edges, just in case...I also like to wrap a little goo around the rocker tower studs, because on most of the heads, these are open to the top of the head, and can weep oil after the parts washer may have removed Honda's OEM powder seal in the threads. You can also pull the studs, install more goo on them, and reinstall, which I've done before, too. Tonight I am both working with 1.5 hands and in a hurry, so I used the 'spread-it' method shown here.

Then I set the new cam from Terry in AUS in the bearings to check the timing: yep, it's the K6/F0 cam. It looks like it has maybe 3000 miles on it, the Parkerizing is still virgin on half of many of the lobes! It opens intake at 0 degrees. So, I must go find my slotted sprocket (wherever that is) and move it forward: I want +5 BTDC opening so the powerband will start around 4000 RPM, not 4500-4800 RPM. Then, when I am on the hiway at 75 MPH in 18T hi gear around 5500 RPM, I will be INTO the powerband, not rolling along the bottom edge of it. Makes for a more response ride, rather like those guys riding the liter-size bikes (or the old GT750 Suzy).  ;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Eydugstr

  • Hot Shot
  • ***
  • Posts: 549
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #227 on: September 10, 2013, 06:50:40 AM »
TY for posting this Hondaman. 

Hope your hand heals soon!  I lived in Broomfield, CO for a couple of years, and although I didn't see a brown recluse, we had black widows all over the place.

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,912
  • Bought her new 4/75
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #228 on: September 10, 2013, 11:56:19 AM »
Hey Mark, will advancing the cam also decrease your redline back to 8000 from the F0 redline of 8500?
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #229 on: September 10, 2013, 10:04:37 PM »
Hey Mark, will advancing the cam also decrease your redline back to 8000 from the F0 redline of 8500?

Yep, it sure does! And, it boosts the torque lower down at the same time. I call this 'making it more ridable' because it both makes it like the earlier engines (K0-K2) and puts the power on tap where you ride most of the time. It starts to run out of volumetrics at about 8000 RPM when the cam is set to open at 5 BTC and close at 35 ABC, where the post-1975 engines have it at open 0 BTC and close 40 ABC. The latter reduces emissions at 2500 RPM, which was the EPA-forced rule of the late 1970s. I don't think I have EVER ridden at 2500 RPM, though...

(Update 9/14): I used the "trapped feeler gage" method this time, as my dial indicator is busy on my lathe just now. This is in my book, too, but here's another sketch of it: set the crank with the #1 intake rocker at full slack on the cam, then set the clearance at .045". Then insert a .005" feeler gage, and turn the crank forward until it just traps the feeler gage. Check the degree wheel: this is .040" lift, which Honda used as their "valve opening" (or, 1.0mm lift) point. I had to grind the slots in my sprocket out about 3mm to get it to open at 5 BTC, which is what I want: this made it close at 30 ABC, so this cam is a little bit "short". I expected that: I started with the K6 cam from Terry, but found it further off toward the -3 degree side, so I went back to my K4 cam I had instead. Most K4 cams were short of the 5 BTC and 35 ABC spec by about 4-5 degrees, and so was this one.

My next "on the ground" setup will be with a 120-90x18 rear tire, 110-90x19 front, 18T front sprocket, so I want my torque to start at about 4500 RPM instead of 5000-5200, as I want better throttle response at 60 MPH in top gear. It will put me fully into the powerband by 80 MPH, for smooth interstate rides up ahead.  This will mean that by about 7800 RPM the "show will be over": the engine will still go much further, but the power will start to fall off. I don't plan on spending much time up there, anyway.

I also did not install valve seals on the exhaust guides: I'd rather let them get a little extra oil, as the old, extra-long, pointy-top cast iron-Stellite guides went 140k miles this way with extremely small wear, because they got some oiling. Honda installed these seals so they could compete with Kawi's advertised longer oil change intervals on the Z1 (1500 miles), part of Kawi's 'nasty' marketing ploy in 1972. "K" was mentioning things like "you won't have to change oil every time you turn around" in some ads: Honda's interval was 800 miles on the sandcast and K0, 1000 miles on the K1-K2 bikes. The seals appeared during the last of the K2 engines. Adding the seals lets the oil stay cleaner longer, for sure: I change mine anyway, so I don't care.  8)
« Last Edit: September 15, 2013, 09:33:20 PM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline RAFster122s

  • I feel like a really really
  • Really Old Timer ...
  • *******
  • Posts: 12,365
  • SOHC4 member # 2605
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #230 on: September 10, 2013, 10:39:11 PM »
Mark, how is the brown recluse bite healing? I have noticed a few spider bites since I moved here but fortunately they aren't poisonous varieties like you are dealing with...just some minor swelling more like a typical mosquito bite. Fang marks and bite pattern differentiate them of course.
David- back in the desert SW!

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #231 on: September 11, 2013, 02:36:12 PM »
Mark, how is the brown recluse bite healing? I have noticed a few spider bites since I moved here but fortunately they aren't poisonous varieties like you are dealing with...just some minor swelling more like a typical mosquito bite. Fang marks and bite pattern differentiate them of course.


The hole where the necrosis ate down has finally closed up. The top 2 layers of skin are gone (poisoned and died), so the remaining layer is real 'touchy' and tender now. It's getting better!
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #232 on: September 11, 2013, 02:39:08 PM »
I just came from the seal shop (Rocket Seals) where I got 200 of a 2.6 x 10.77 mm O-ring. This baby is perfectly-sized for sealing the oil feed passages with the modern uncoated head gaskets that are 1.1mm thick, like the Vesrah and some others. If anyone needs some, PM me! It will solve the too-soft/too-thin pink O-ring problem with the Vesrah kits.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline BPellerine

  • Master
  • *****
  • Posts: 2,222
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #233 on: September 11, 2013, 05:50:59 PM »
I thought about this and pmd Mark about tis very thing.bill
1978 CB 750K ard and webers
another anfob

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #234 on: September 11, 2013, 10:00:46 PM »
I thought about this and pmd Mark about tis very thing.bill
Bill: there's 2 of the 2.55mm thick one in the pack I sent you last week. You might even get it this week? These new ones are about .65mm thicker than even those. I have been using the ones I sent you with good results, so far. This fortunate find is even better! :D

I got it closed up tonight, woohoo! I had bought all new cam cover screws from Honda, turns out they are all too short. :( The original ones are 62mm long, the Honda replacement parts are 60mm for the "delta part" versions. Drat. I put the cover on with the old screws. Looks sorta sad...I hate the thought (of time) of getting 10 new 65mm screws and having to shorten them all, as the blind holes are 64mm deep. That's the way the K0/K1 heads were, in those days. A few of them are open thru to the bottom of their fins, so maybe I'll see tomorrow if I can scrounge something better together. All the rest of the engine has nice, new, screws!

I'll sleep better tonight: 3 days ago we had another storm blast through here, and when I came home from work I found it had blown the cover off the engine. It was a rainstorm, so it didn't look like much dirt got ingested, just a little dampness and a few drops of water. Tonight, with the ports all covered, no more worries. :)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Bankerdanny

  • Eventually I will be old enough in reality to be
  • Really Old Timer ...
  • *******
  • Posts: 7,626
  • Endeavor to persevere
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #235 on: September 12, 2013, 08:47:11 AM »
I got it closed up tonight, woohoo! I had bought all new cam cover screws from Honda, turns out they are all too short. :( The original ones are 62mm long, the Honda replacement parts are 60mm for the "delta part" versions. Drat. I put the cover on with the old screws. Looks sorta sad...I hate the thought (of time) of getting 10 new 65mm screws and having to shorten them all, as the blind holes are 64mm deep. That's the way the K0/K1 heads were, in those days. A few of them are open thru to the bottom of their fins, so maybe I'll see tomorrow if I can scrounge something better together. All the rest of the engine has nice, new, screws!


Time to invest in a tabletop vibrator unit to clean them up and an Eastwood home plating unit for fresh zinc coating.
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline Pecantree

  • Hot Shot
  • ***
  • Posts: 447
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #236 on: September 12, 2013, 11:48:06 AM »
Mark:
I'm unclear on where these o-rings go. Are these only for K0 thru K2/3?
These are  my measurements from new Cycle-x rubbers.
The oil jets are 1.9 x 5.9
The oil pucks are 2.8 x 26
That leaves the sleeves over the head studs 1.9thick x 8.3high x 14.2od
Course this is a K6 head and I'm using the dowels too.

Hope this isn't a dumb question.
Thanks
Steve
http://www.harvestclassic.org/

"The suspect had experienced a ballistic interlude earlier in the evening" Miss Pao said, "Regrettably not filmed, and relived himself of excess velocity by means of an ablative technique."         ......    ?    ........         "She say you have road rash."

Offline danfr

  • Enthusiast
  • **
  • Posts: 211
    • Apollo Motorcycles
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #237 on: September 12, 2013, 12:27:18 PM »

4. Add sealant around the whole cam chain tunnel. Honda did: I'm sure it was important!


Are you using Permatex no.2? The same stuff as what you use with the pucks under the cam tower?

I was considering spraying the whole head gasket down with Copper Spray a Gasket, but am open to a different approach if you have found a better solution.

Oh, and I'll PM you for a set of those o-rings for my K4.

Thanks
Dan
Apollo Motorcycles
-------------------------
71 Commando
74 CB750K
74 CB350F

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #238 on: September 12, 2013, 03:28:19 PM »
Mark:
I'm unclear on where these o-rings go. Are these only for K0 thru K2/3?
These are  my measurements from new Cycle-x rubbers.
The oil jets are 1.9 x 5.9
The oil pucks are 2.8 x 26
That leaves the sleeves over the head studs 1.9thick x 8.3high x 14.2od
Course this is a K6 head and I'm using the dowels too.

Hope this isn't a dumb question.
Thanks
Steve

These are the 2 in the center rear of the cylinders, which feed the oil to the head. They are the 2 recessed ones nearest the cam tunnel, at the back.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #239 on: September 12, 2013, 03:30:07 PM »
I got it closed up tonight, woohoo! I had bought all new cam cover screws from Honda, turns out they are all too short. :( The original ones are 62mm long, the Honda replacement parts are 60mm for the "delta part" versions. Drat. I put the cover on with the old screws. Looks sorta sad...I hate the thought (of time) of getting 10 new 65mm screws and having to shorten them all, as the blind holes are 64mm deep. That's the way the K0/K1 heads were, in those days. A few of them are open thru to the bottom of their fins, so maybe I'll see tomorrow if I can scrounge something better together. All the rest of the engine has nice, new, screws!


Time to invest in a tabletop vibrator unit to clean them up and an Eastwood home plating unit for fresh zinc coating.

I've thought of something along those lines, for reloading...but I would like it to be bigger, like for sprockets and other pieces-parts?
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #240 on: September 12, 2013, 03:32:29 PM »

4. Add sealant around the whole cam chain tunnel. Honda did: I'm sure it was important!


Are you using Permatex no.2? The same stuff as what you use with the pucks under the cam tower?

I was considering spraying the whole head gasket down with Copper Spray a Gasket, but am open to a different approach if you have found a better solution.

Oh, and I'll PM you for a set of those o-rings for my K4.

Thanks
Dan

Yeah, their non-hardening stuff. I really wish I could find some FelCoBond, but they don't sell it around here anymore. That stuff was excellent for this task, especially on the old CB/CL72/77 engines which had nothing sealing these passages but the head gasket. They often leaked, more than a little. It strongly resembled rubber cement, but was oil- and gas-proof.
« Last Edit: September 15, 2013, 09:18:33 PM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline RAFster122s

  • I feel like a really really
  • Really Old Timer ...
  • *******
  • Posts: 12,365
  • SOHC4 member # 2605
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #241 on: September 12, 2013, 06:10:47 PM »
I got it closed up tonight, woohoo! I had bought all new cam cover screws from Honda, turns out they are all too short. :( The original ones are 62mm long, the Honda replacement parts are 60mm for the "delta part" versions. Drat. I put the cover on with the old screws. Looks sorta sad...I hate the thought (of time) of getting 10 new 65mm screws and having to shorten them all, as the blind holes are 64mm deep. That's the way the K0/K1 heads were, in those days. A few of them are open thru to the bottom of their fins, so maybe I'll see tomorrow if I can scrounge something better together. All the rest of the engine has nice, new, screws!


Time to invest in a tabletop vibrator unit to clean them up and an Eastwood home plating unit for fresh zinc coating.

I've thought of something along those lines, for reloading...but I would like it to be bigger, like for sprockets and other pieces-parts?
The Cabelas model 400 vibratory tumbler runs about $60 plus shipping if you don't have one nearby. It has a nice large 12" diameter bowl that is good sized and can handle 600 rounds of .38, will fit a sprocket, right?
Do you need larger than this? Granted you might have more wear from a sprocket than your brass. But, it is reported to be quiet and good quality.
The Cabela's mod.el 400 vibratory
David- back in the desert SW!

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #242 on: September 12, 2013, 09:48:56 PM »
I got it closed up tonight, woohoo! I had bought all new cam cover screws from Honda, turns out they are all too short. :( The original ones are 62mm long, the Honda replacement parts are 60mm for the "delta part" versions. Drat. I put the cover on with the old screws. Looks sorta sad...I hate the thought (of time) of getting 10 new 65mm screws and having to shorten them all, as the blind holes are 64mm deep. That's the way the K0/K1 heads were, in those days. A few of them are open thru to the bottom of their fins, so maybe I'll see tomorrow if I can scrounge something better together. All the rest of the engine has nice, new, screws!


Time to invest in a tabletop vibrator unit to clean them up and an Eastwood home plating unit for fresh zinc coating.

I've thought of something along those lines, for reloading...but I would like it to be bigger, like for sprockets and other pieces-parts?
The Cabelas model 400 vibratory tumbler runs about $60 plus shipping if you don't have one nearby. It has a nice large 12" diameter bowl that is good sized and can handle 600 rounds of .38, will fit a sprocket, right?
Do you need larger than this? Granted you might have more wear from a sprocket than your brass. But, it is reported to be quiet and good quality.
The Cabela's mod.el 400 vibratory

Thanks, RAF, I'll check that out! A Cabela's just opened here in town about 2 months ago. Haven't been there yet.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline 70CB750

  • Labor omnia vincit improbus.
  • Really Old Timer ...
  • *******
  • Posts: 14,802
  • Northern Virginia
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #243 on: September 13, 2013, 02:03:58 AM »
LOL, I was :)
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline Eydugstr

  • Hot Shot
  • ***
  • Posts: 549
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #244 on: September 14, 2013, 10:01:20 AM »
Installed the head seals after the retorque today. Pix below: with the crop of too-thin head seals we keep seeing, here is a way you can check the ones you got in your gasket kit (or elsewhere, like PartsNmore or CB750Supply, etc.).

First, check the step depth of the head hole. Then, check the thickness of your seal. You need at LEAST .030" compression, .040" is better. The too-thin ones are only about .005" thicker, which won't seal when the head heats up and the hole becomes deeper.

Hondaman, I'm still fighting the math on this...Even with the thicker/wider Cycle X pucks I'm still coming up with only a  .027" difference (K2 head, depth of puck hole .085", thickness at outer band/edge of Cycle X puck .112").  Or should I try a third set of pucks?

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #245 on: September 15, 2013, 09:02:19 PM »
Installed the head seals after the retorque today. Pix below: with the crop of too-thin head seals we keep seeing, here is a way you can check the ones you got in your gasket kit (or elsewhere, like PartsNmore or CB750Supply, etc.).

First, check the step depth of the head hole. Then, check the thickness of your seal. You need at LEAST .030" compression, .040" is better. The too-thin ones are only about .005" thicker, which won't seal when the head heats up and the hole becomes deeper.

Hondaman, I'm still fighting the math on this...Even with the thicker/wider Cycle X pucks I'm still coming up with only a  .027" difference (K2 head, depth of puck hole .085", thickness at outer band/edge of Cycle X puck .112").  Or should I try a third set of pucks?

Hmm...well, there's always the 'shim it' method, too? This would involve getting some shim stock like brass or aluminum (Ace Hardware has sheets of it in their bolts aisles). Make a round shim of, say, .008" thick material and set it into the hole first (with some sealant around the edges) and then set the seal on top of it (with sealant again). This is my "go to next" plan when we either A.) can only get thin ones or B.) cannot get new  ones at all. It should work fine, by pressuring the seals the right amount. If you're at .027" now, then use .005" to .008" metal shim to get the desired pressure.

It is interesting to note: the ones I just pulled out of my head have 90k miles on them, no leaks. I replaced them in 1980 when I did the first to-end overhaul at 55k miles then. I have them in my "good used" collection.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #246 on: September 15, 2013, 09:11:26 PM »
Well, despite the rain, flood, hail, in-laws in town, etc....I got some good things done on the engine this weekend!

I decided to forego lunch for the next few days and went to Ace for 10 of their extra-large head (and extra-expensive) 6x65mm screws for my cam cover. It looked so sad with those OEM, much-removed, crusty-looking old screws...I kinda like the oversized screw heads, gives the engine a certain caricature-d look with these big, shiny screw heads like buttons, everywhere. It will be a great SOHC4 conversation starter (like this bike has ever needed that around here) in parking lots!  :D

This did bring up a point I left out of my book: the Old Factory engines had specially-made 62.5mm cam cover screws, which were discontinued in 1990. The New Factory cam covers have recessed holes for each screw (2mm deep) so the more common, less-expensive 60mm screws could be used. To use 65mm screws in the Old Factory engines, with their 64mm deep threads, you have to add a washer under the screw head: this is why some aftermarket chromed Allen-Head kits come with those washers. There's lots of confusion about that out there, and some bad products from this issue as well.
« Last Edit: September 18, 2013, 09:49:11 PM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 13,839
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #247 on: September 15, 2013, 09:17:08 PM »
Next: got the engine cases painted and polished the top fin and some of the cam cover. The top end is naked, but the finish was pretty rough. So, I shined it up with some 220/400/1000 grit and Simichrome to make it look a little better. It will be hidden behind the Vetter lowers much of the time, anyway, but when it's streaking the streets, at least it won't be objectionable?  ;D

Then came the starter. Easy to see why it was causing problems! I cleaned it out, polished the commutator with Scotchbrite, added new brushes, greased the bearing (all just like in the book!). Oughtta be good for another 100k at least.  :)
« Last Edit: September 16, 2013, 09:48:22 PM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline jerry h

  • Hot Shot
  • ***
  • Posts: 392
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #248 on: September 15, 2013, 10:42:46 PM »
Hi Mark,
I really love all of the little history bits you work into your rebuild.  Of course I had to run out to the garage and check my K2 cam cover.... no recess, so old factory.  (for trivia sake, where was the "old factory" located?) 
"It is not the critic who counts, the credit belongs to the man who is actually in the arena, whose hands are covered with grease and oil."

K2 http://forums.sohc4.net/index.php/topic,105097.0.html

Offline Eydugstr

  • Hot Shot
  • ***
  • Posts: 549
Re: Headline: Hondaman gives in and rebuilds his old friend!
« Reply #249 on: September 16, 2013, 10:58:44 AM »
Installed the head seals after the retorque today. Pix below: with the crop of too-thin head seals we keep seeing, here is a way you can check the ones you got in your gasket kit (or elsewhere, like PartsNmore or CB750Supply, etc.).

First, check the step depth of the head hole. Then, check the thickness of your seal. You need at LEAST .030" compression, .040" is better. The too-thin ones are only about .005" thicker, which won't seal when the head heats up and the hole becomes deeper.

Hondaman, I'm still fighting the math on this...Even with the thicker/wider Cycle X pucks I'm still coming up with only a  .027" difference (K2 head, depth of puck hole .085", thickness at outer band/edge of Cycle X puck .112").  Or should I try a third set of pucks?

Hmm...well, there's always the 'shim it' method, too? This would involve getting some shim stock like brass or aluminum (Ace Hardware has sheets of it in their bolts aisles). Make a round shim of, say, .008" thick material and set it into the hole first (with some sealant around the edges) and then set the seal on top of it (with sealant again). This is my "go to next" plan when we either A.) can only get thin ones or B.) cannot get new  ones at all. It should work fine, by pressuring the seals the right amount. If you're at .027" now, then use .005" to .008" metal shim to get the desired pressure.

It is interesting to note: the ones I just pulled out of my head have 90k miles on them, no leaks. I replaced them in 1980 when I did the first to-end overhaul at 55k miles then. I have them in my "good used" collection.

TY for the response Hondaman!  Will try the shim method.