Topic: 1972 CB750 - Vermont Winter Project - Into the second Summer

[VTCBike750]

Well Ive started to work out some of kinks on the bike. It hasn't been that easy in Vermont, with the past 2 months setting precipitation records. While getting it inspected at a local bike shop, took off before the rain, and never got the sticker! Got it a week later. The bike also has a new front tire, which was BADLY needed.

The flashers work great now, that was just a moronic mistake of mine.
http://forums.sohc4.net/index.php?topic=89750.msg1004907#msg1004907

The neutral switch sometimes works, but other times appears to be somewhat grounded. Ive checked the wire, but its ok. It gets better after running the bike for a while, I'm thinking the switch is stuck sometimes. I'm gonna run some seafoam through the oil and see if that helps. If it doesn't, Ill take it out and cleaning it.

I dont have a baffle in the 4-1 exhaust, but it did come with the baffle end cap. I'm wondering how this effects the needed back pressure from the the exhaust? The bike does run a little rough and Ive noticed a distinct popping from the exhaust, particularly around 3-5K RPMs. Im planning on syncing the carbs and setting the advance timing. But I want to run some Seafoam through the bike first. Called Seafoam, its completely safe to use on a POR-15 lined tank.

The bike is also a PITA to shift sometimes.  I adjusted the clutch cable, so I'm beginning to think its a dragging clutch. The clutch was stuck when I got the bike. I'm running the bike with cheap auto store 10w-40 oil right now. Just wanted to run it in the beginning and plan to change the oil soon. Thinking of changing it to 20W-50 and seeing if that helps.

Other than that, bikes great. Starts easy, just need to smooth some things out .

[VTCBike750]

Took the bike out last weekend and decided to really open her up, see what she can do.  This is my first 750. Holy #$%*! That's all I have to say. An unbelievable bike, Loves riding at 4-5k RPMs at 70 MPH. The whole time Im just thinking, I hope I don't see a cop. Definitely glad I took the time to get the rear tire balanced, very smooth.

I definitely didn't adjust the clutch right. I think I over adjusted it, causing the clutch to be too tight. I had planned on making it to Americade with this bike, but its just not gonna happen. I have too much going on at home, and a few things to do to the bike before a long trip.

Today Im gonna readjust the clutch, put Seafoam in the oil and gas tanks, and go for a long ride.  If I cant make it to Americade might as well get out on the bike. Then time to change the oil to 20W50. Hoping the clutch will love it. If I have the time, then Ill sync the carbs.

And Ive realized that I haven't even taken the time to post any pics since Ive gotten it out of the garage.

[CafeDawg]

Hey Adam,
Yup I had the same reaction to my 750, went to pass two cars on a straight and when I looked down at the speedo was doing 90.  Took me by surprise didn't expect such quick acceleration.  Now if we could just get it to stop F*ckin raining, looks like no riding this weekend here in VT.  Good luck with the tweaks and pray for sun.
Respect
CD

[VTCBike750]

CD,
Its funny how that sort of thing happens. You been out? Its stopped raining.

So I took the bike out and it hated my clutch adjustment. Adjusted it again, much better. The Seafoam seemed to help a little, but the bike was still running rough at 1k RPMs. I synced the carbs yesterday.  WOW that is not rocket science, very easy  . 1 & 2 were lined up, but 3 & 4 were both off.  Lined them all up, much better. The bike still wants to stall out at 900-1000 RPMs, but I think its the timing. Got done with it all yesterday, greasy and smelling of gas, parts everywhere in the back parking lot, and I get called into work! Oh well,
 I knew it was a gamble that I could be called in. At least I got them synced.

I looked at the points finally, something I should of done months ago.  They're chinese made K&S and there was NO gaping. Corrected that, but they have pitting and in need of replacement.  At this point Im just waiting on a new set in the mail.  Bought a set of cheap Japanese made points on Ebay, they turned out to be Daiichi  .  Im gonna give them a shot, but I have a NOS points plate coming in the mail. 

Taking it for a ride today and gonna see how the carbs sync feels.

[CafeDawg]

Sounds like things are coming along.  Also sounds like we have similar things going on with our bikes.  I don't have any baffle in my exhaust either and get popping and wonder what issues might occur by running it this way.  Have some rough running around same RPMs and think it's timing/dwell issues, when I have some money in a month or so I plan on bringin her into The Daily Rider and have it checked out.  Do you know the guys @ Daily Rider?  I have been riding some, commuting to work, a little cold tonight but lovin the days.  I put a one-up/solo seat on the bike and am digging the new riding position, now just need some rearsets
Respect!
CD

[VTCBike750]

They are, other than a pain in the ass gas leak  yesterday that filled the #1 carb bowl all the way and into the air box. I think the float bowl got stuck.  Ended up taking out the air box and double checking things.

I dont have a baffle, just the baffle end cap. Something the PO did. Im not too sure how much this effects the back pressure build up in the exhaust?

When do you have popping? Accel or Decel? Mines on Deceleration. 
I messed with the idle air screws the other day when I synced the carbs. I first had them 1.25 turns out for about 91 miles. I tried them 1 turn out, bike liked it better.  Then adjusted them only 0.5 turns, definitely a different acceleration response. Changed them to 1.5 turns, BAM! big back fired.  Right now I have them adjusted 7/8 turns, but havent fired her up yet.  We'll see. 
Have you tried to synced the carbs at all?  Id definitely take the money and buy a carb sync tool rather than pay someone to do it.  Might as well buy one, Its gonna cost you about the same in labor at the daily rider. Got mine at Land Air.
Do you have a timing light? I got one pretty cheap online. Havent tried it yet, waiting on the new points.

I like the Daily Rider. The owner Mark is a great guy. He also seems pretty knowledgeable on Honda SOHCs.  One day I found an old TV show I guess he made on one of the basic cable public channels. It was on maintaining I think a 78 750 SOHC.

So far they've checked out the bike, inspected it, and swapped out the front tire. I also brought them the rear wheel for balancing. But like any mechanic, labor costs money.

You have a pic of your bike?

[CafeDawg]

Adam,

The popping is on deceleration, I don't really mind it unless it's contributing to rough running.  Yup the guys at the Rider are kewl, almost bought a bike from them.  I don't have a timing light and haven't synched the carbs although I believe the PO did.
I adjust my idle screw on every ride, when it's cold I turn it maybe one turn and then back it off at the first stop when she's had a chance to warm up.  I prob should invest in both tools but cash is an issue and I don't have a space to work on the bike, driveway doesn't cut it, although the small changes to it have all been done their.  For now it run's well enough to get back and forth to work.  Hope the gas leak is a simple fix.  Here's the link to my build thread.....http://forums.sohc4.net/index.php?topic=89745.0
Respect
Chris

[VTCBike750]

So havent had a chance to swap out the points as of yet. Sort of got wrapped up with another problem.

The 750 doesnt like shifting into 1st, Neutral, or 2nd. No problem with 3rd-5th. Has that wonderful chatter. Once in 1st it will shift fine while running and the clutch pulled in, but only for about 5-6 cycles through 1st and 2nd. The last ride I went on I noticed that the bike had issues going into neutral after running for a while.  The 550 that I had before this did the same thing. 

So short of taking the engine out and opening it up, my weekend plan was to try a few things first per 72hondacb750's instructions:
http://forums.sohc4.net/index.php?topic=78643.0

- Replace the o-rings on the oil pump

- Replace the o-ring on the countershaft oiler.

- Drill the clutch basket to improve oil flow across the clutch.

I was also going to change the oil to 20w-50 motorcycle oil.  Get the cheap 10w-40 out of there. I got the oil filter housing bolt off with out too much trouble with the use of a 12mm 6 sided wrench and a hammer.  The PO decided it was to NEVER come off.

Well since October Ive learned that not everything goes as planned. 

Ran the bike and noticed that the exhaust around #1 was leaking at the head. No problem right, I have some crush washers in a gasket kit that came with the bike. well they look a little different, but they fit so Ill use them.  Well they are a little thick and dont compress well. 

Well F*#@!. Long story short I stripped some threads out of the 2 exhaust bolt holes for the 4th exhaust.
http://forums.sohc4.net/index.php?topic=91844.msg1025564#msg1025564
The PO must have stripped some out cause there are more threads missing than what I jacked up. So now Im now missing 3/4 of the threads in the 1st hole and 1/2 the threads in the 2nd hole.

Bought a thread repair kit at sears that I may not need, but Im hoping that the few threads in there can work to hold the exhaust on there. Bought some new exhaust gaskets, THE RIGHT ONES, and will try things when they come in.  If that doesnt work, time to helicoil.

But the good news is I dropped the pan and oil pump, and changed out the oil pump o-rings without a problem.

The big victory was removing the 4 screws that hold on the countershaft oiler. Quality impact driver and a dremel tool! Thought for a second that I was gonna strip everything though.


Im gonna get new screws though before I finish things. 

I also had a chance to modify the clutch




This is what I came up with.  I added a total of 8 holes.


Just a little countersunk

So now I just have to wait for new exhaust gaskets and countershaft oiler screws.  Cross your fingers that the exhaust bolt holds.

[VTCBike750]

Also figured its time that I post some pictures of the bike.

[VTCBike750]

All work finished. Exhaust bolt hole threads repaired and retapped, exhaust on, all bolts torqued down to 80 inch lbs, and no leaks.

Countershaft bearing oiler o-ring replaced, oil pump o-rings replaced, clutch hub modified, clutch spring seats added, 20w-50 in bike, and biking shifting as smooth as butter!

[CafeDawg]

Good to hear everything worked out for ya,  tragedy narrowly adverted.  You must be psyched that everything has come together and be ready to get out on the road.  Let's hope the sunshine keeps up.
Respect
CD

[dagersh]

Nice job, great info!

Now get riding on those beautiful Vermont roads!

Gersh

[VTCBike750]

Nice job, great info!

Now get riding on those beautiful Vermont roads!

Gersh

So far so good. 

Been working on the timing. Ive managed to improve things.  Would of like to use a timing light, but it lasted about 20 seconds that crapped out. Go figure it was chinese and cheap.

[VTCBike750]

Well I might not be cruising the Green Mountains for a while!
http://forums.sohc4.net/index.php?topic=92922.0;topicseen

So far Id put 200 miles on my 750. Today I went out, hopped on the highway and put 100 miles on her.  See what she can do and how she handles it. Awesome , consistent RPM around 6K and 70-80 MPH.

Since Ive had the bike, I have noticed a little oil weeping from the left side of the head. PO even pointed it out. Also, when I first ran the bike in Nov. #1 didn't fire.


However, on the ride back home I realized that she didnt quite have the power she normally does. Checked the exhausts at one point, all warm.  When I got home checked the exhausts again, well guess what #1 is cold.  2, 3, 4 all HOT. #1 Cold  . Limped home on 3 cylinders.

Halfway through the ride I noticed the same weeping oil, but thought nothing of it its normal. Get home to find this.



First thing I noticed was a little bubbling of oil out of the nut next to the plug. 


Pull the plug and tada! Fouled with oil. I did check and #1 is getting spark



I also pulled #4 plug, its solid black, but not oil fouled.  Just running rich.


Also, #2 plug looks great, #3 Black

So fast forward to Sunday. Clean the bike. Change out the plug, Great spark!  Checked to make sure the Stud nut was torqued down.  Incrementaly build up the torque and chickened out at 150 In lbs.  Ive heard bad bad bad things about snapped studs.  Well the nut didnt tighten down, so thats a good thing .

Run the bike with the wonderful ethanol free gas that I just got and proceed to fill the parking lot with smoke.  All the oil in the #1 cylinder plus whats in the exhaust is smoking.  Get the warm and check the oil.  WAY TOO MUCH. Above the top mark on the dip stick. So I guess Ive figured out why I blew oil all over my bike >(.

This just confuses me because just the other day I was getting a flickering oil light, ran the bike, and the oil wasnt even on the dip stick.  Pull a quart out of the oil tank and run the bike.  Its a little low right now but within specks on the dip stick. 

Run the bike some more and it starts running rough.  #1 cold.  It has great spark. Thanks to the help of Jawntybull the other day, I reluctantly pulled the carbs.  Learn that 1. didnt clean the inside of the jet holes, which are terrible, jets look great, and Im missing a brass insert that's part of the carb breather inside the body of the #2. 


Start looking at the other 2 sets of carbs that I have and well that got posted here.
http://forums.sohc4.net/index.php?topic=93021.0 

Im gonna check the Crankcase Breather Hose tomorrow.

And...

[VTCBike750]

Crankcase breather clear.

Another set of carbs, so clean you could eat off them with copious amounts of Deep Creep for added flavor, and bench synced.

Bike reassembled running better than ever. Perfect idle at 1000 RPMs. Vacuum sync next.

Still has that weeping oil.

[VTCBike750]

Ran 100 Miles today down Route 7, then up 17 (great ride) to 100 N over to Waterbury, and up 89 back to Burlington. 

Bike ran great except for a newly developed exhaust leak!  I dont know why but #1 is leaking again.  #1 was the reason I replaced them 300 miles ago. Damn you #1, haha.

Tomorrow Im gonna get everything to do a compression test.  See how they're doing.

I also need a name for my bike.

[VTCBike750]

Since Ive had recent problems with my #1 cylinder (fouled plug), Ive decided to do a compression test advised by my Uncle.

Dry
1         2         3        4
130     125     122    125

Wet
1          2        3        4   
135     124     126    131

Not too bad.  I thought the Valves on #1 would be burnt up given the apparent cycle of oil fouling and running.  Little surprised by #2.  I did have a hard time getting a precise amount of oil inside the #2 and 3 cylinders, so that could explain the little to no increase.


Also checked my plugs after the most recent 100 mile ride.

#1


#2


#3


#4

[VTCBike750]

I also disassembled then reassembled the #1 exhaust collar again tonight.  Tightened everything down and the exhaust pipe is now completely loose, as though there isn't even a gasket there?

[VTCBike750]

Sooooo, New exhaust gaskets in and no leaks. Shes running great!

I did find out that the newer EMGO ignition switches cant handle the amps of a 750! The insulation on the black wire is burning off.

[jaguar]

might be something in your wirs, but emgo doesnt make anything all that well....

[VTCBike750]

Im hoping its just a crappy EMGO switch 

Going off of this.
http://forums.sohc4.net/index.php?topic=70784.0

[VTCBike750]

She has got to be cursed, some bad Juju or something 

I got a new ignition switch installed, to replace the EMGO switch thats burning up.  Even scored an ignition switch frame mount so Im pretty excited about that. Get her running, its been about 2 weeks and it takes a while for her to get settled and warmed up.  Rev the engine a few times.  All is good until POP!

Some how the exhaust on #1 header is leaking AGAIN . Not happy, I just spent a week waiting for an ignition switch and now this, again. Not to mention, with everything tight, the #1 exhaust is loose in the head. I can tap on it and hear it rattle.

Well temporary solution is toss 2 gaskets in #1, hope the other ones dont leak (much), and go for a ride. 

Drop exhaust, place 2 gaskets in, attach exhaust, and strip those remaining holes from the #4 exhaust that gave me some trouble in July. 

So I get a ride from a buddy to the autostore and lowes and helicoil both exhaust holes for #4. Probably going to helicoil a few other ones that look less than great. 

I get the exhaust mounted with 2 gaskets in #1, #4 is leaking the slightest amount. Then take my bike to a buddies garage to wait out the hurricane, which Im glad I did since there are trees going down on my street.

My goal is to helicoil the few holes that could use it and swap the bolts out with studs (thanks for the help madmtnmotors)


Im also contemplating using these


So hopefully it works, bikes not out of commission but not running perfect.

[VTCBike750]

So yesterdays checklist invloved

putting on some new Randakk Grips. So far very happy
checking float bowl levels (All even)
static timing, points (changed a little), valves
Helicoiled 4 more exhaust bolt holes (total of 6 Helicoiled now)
Installed studs
remounted exhaust with new copper exhaust gaskets
So far so good.



Thought Id also show a picture of my "garage" that Ive been working in all summer
Not to shabby huh? Ok, yeah I wish I had a garage.


Went to fire up the bike, and she only ran on 2 cylinders, 1-4 are a no go. 

Further inspection today shows things are way off.

This is what Ive been able to get to so far


1-4 points at F mark


1-4 point open all the way to 0.014" (Not at F mark)


2-3 points at F mark


2-3 point open all the way to 0.014" (Not at F mark)

When checking things with static timings, 1-4 are ok (plate adjusted all the way) and 2-3 are a little early (also adjusted all the way.

The good news is it fired right up, poured in a bottle of seafoam, and went out for a 75 mile ride. Still wanna sync the carbs again and get the timing spot on.

[VTCBike750]

So realized that I haven't posted on here in a while. Got things running great.  Followed TwoTired's recommendation for for a jig to keep the plate from moving.  That worked great. 

Resynced the carbs.  She'll hold a steady idle at 1000.  Found out one of my carb boots was off set about 3 degrees causing a leak.  Fixed that and hanging idle no more. Did have some charging issues which were easily fixed by cleaning up and adjusting the voltage regulator

Took the bike to work one morning down 89 and route 100.  A nice 46 miles at 48 degrees. 

Rode the bike for one last long ride last weekend on the ferry to NY and back.  A nice 85 mile round trip.  Here's a pic on the ferry.


I tried to go for a ride on Saturday.  A little too cold at 33 degrees and decided its time to put the bike up for the winter.  It was a good riding season, 1200 miles.  I got a lot of help on here.  Rebuilt a lot more than I thought was needed and what I could do.  If it wasn't for this site I may have thrown in the towel.  Thanks to all who helped. 

For the winter the grand plan is to pull the engine and do a top rebuild, lap the valves, replace the studs, hopefully get rid of that PITA oil leak, and probably more (rebuild the swingarm).  Shes burning some oil as well.  My landlord cleared out an even bigger spot for me to work on in the utility room than I had last year.

Im also thinking Ill take a stab at painting the tank and sidecovers. I wanna keep it the original flake orange.  The tank looks a hell of a lot better in pictures and the right side cover just cracked  .  Probably time to get some replacements that arent 40 year old plastic. 

[lucky]

Good looking project. I live in northern Vermont - Burlington area. Where are you?

I had to take out a bad kreme job and used M.E.K. with good results.

Thanks KB02, Im in Burlington.
So far Ive gotten most of the kreeme out.  There are a few smaller pieces that Im hoping to get out tonight and then seal the tank.  Wondering if MEK would of been a better option though.

If you read the instructions with the Kreme kit, it says to use MEK to remove a bad KREEM liner