Author Topic: CB750K3 pickup.  (Read 11652 times)

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Offline mrbreeze

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Re: CB750K3 pickup.
« Reply #25 on: September 30, 2015, 04:07:53 PM »
So if in fact little or no oil is coming through......what's the next step (assuming the gauge shows good pressure)? My guess is to remove the valve cover and blow air through the oil jets. If so....another good reason to have a frame kit installed.
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Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #26 on: September 30, 2015, 04:11:15 PM »
So if in fact little or no oil is coming through......what's the next step (assuming the gauge shows good pressure)? My guess is to remove the valve cover and blow air through the oil jets. If so....another good reason to have a frame kit installed.
believe I already posted what is necessary to fix oil jets...and I feel I am still young and strong enough to do without the frame kit (cuz the frame is not so young or strong)
If it works good, it looks good...

Offline mrbreeze

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Re: CB750K3 pickup.
« Reply #27 on: September 30, 2015, 04:15:02 PM »
Just seems like a lot more work Sean. If I ever need to clear my oil jets I'll do a search for your method.
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Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #28 on: September 30, 2015, 04:31:29 PM »
Just seems like a lot more work Sean. If I ever need to clear my oil jets I'll do a search for your method.
it is a lot more work, I just don't agree that your frame is just as good after using a frame kit.  How to fix oil jets is posted several posts earlier in this thread.
If it works good, it looks good...

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #29 on: October 06, 2015, 03:38:40 PM »
Well the bike's still sitting on the battery tender.

I ordered the gauge from Joker Machine and watched for 7 days as the package sat in Las vegas after leaving the JM store in Lake Havasu.

Though the package was insured, USPS suggested I wait to see if it turns up, because apparently the process to get reimbursed can take a while. Naturally I got a little frustrated, but kept full composure and gave Joker Machine a call to ask if they ever had experienced it happening in the past.

The gentleman who I spoke with said that it happened so rarely, that he'd just go ahead and mail out another one to me right then, no questions asked; I was stunned. 20 minutes later I had an email saying a shipping label had been created. So naturally, I am going to highly recommend them for their customer service.

I did, however receive this little gem from Japan (hence the *C instead of *F).



Fit and finish seems to be good, and although it's not visible while riding, it would be easy to check at lights/stop signs, etc.

Will keep Y'all posted on what the oil pressure does when I install the other gauge.
1973 CB750

Offline SOHC4 Cafe Racer Fan

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Re: CB750K3 pickup.
« Reply #30 on: October 06, 2015, 03:55:46 PM »
Although the Joker stuff is pricey, their customer service is awesome.

I think their prices went down since they moved to AZ.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
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"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
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2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
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Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #31 on: October 06, 2015, 07:49:51 PM »
Satisfied either way!

Regardless of what happens when I fire this up once more, I have come to peace with the fact that I'm not riding this until the spring.

That makes everything easier to deal with.
« Last Edit: October 06, 2015, 07:51:48 PM by BrosefStalin »
1973 CB750

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #32 on: October 20, 2015, 05:59:30 PM »
Back again, 14 days later.

I received and installed my joker machine gauge oil pressure gauge. Being white faced with an orange needle, it matches the oil temp gauge very nicely. It might be nice to get a white faced overlay for the stock speedo, if I choose to keep it, and if it's possible.



To pick up where I left off: I don't think I'm getting oil to the top of the head (valves/tappets). I hoped that the Joker machine gauge would at least help diagnose this issue, since I no longer have an idiot light for it.

Everyone says that the oil pumps on these things rarely break, so I've been told that it's probably not that. Here's what happened when I started it up (and let it run for a minute and 30 seconds total). One thing I wanted to do, since I'm afraid I might not be primed properly, is dump a 1/3 quart of oil down the number 4 intake tappet. So I do that.

After that, I start it (and man does it start right up. Not even a full spin on the starter and it's started & idling), let it run for about 50 seconds, and then took this video:


Youll see that oil is not "spraying" out of the exhaust tappet cover, but there appears to be oil moving around up there. It seems like the experienced posters in this thread are right (not that I didn't think they'd be), it looks like the oil jets are certainly clogged, eh? As you can see, the oil pressure at idle is a hair under 70 psi. Is that normal?

Lastly, after a minute and a half of idling (with a fan, mind you), my oil temp gauge on the oil tank did not rise above 23.5 celsius (74.3 Fahrenheit ). Is that a normal reading for the amount of time I was idling? Or is this a symptom of the oil not circulating, indicating a faulty oil pump? Will gladly accept all criticism and ideas.

Also, I can certainly start a thread elsewhere if I'm breaking the rules in this forum.

Thanks in advance for any input! Looking forward to a bunch of fun engine maintenance this winter.

« Last Edit: October 20, 2015, 06:05:42 PM by BrosefStalin »
1973 CB750

Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #33 on: October 20, 2015, 06:39:58 PM »
I would say that a valve cover that dry will result in complete valve train failure in less than 100 miles, especially considering you just dumped a bunch of oil in there...70psi at idle cold is right in the normal ballpark...I have no data or experience on the oil temp but would assume that the pump is working fine based on oil pressure.
    I have tried to clear blockages with compressed air and various solvents/cleaners sprayed into the oil gallery with no success...but fear not, lots of help here for pulling that 200lb. lump and removing camshaft. :-\
If it works good, it looks good...

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #34 on: October 21, 2015, 04:53:40 PM »
Ah well. Time to rig up something to pull the motor. Might as well just do it now so I can carry the bike into the basement piece by piece as opposed to rolling it down like I did last year.
1973 CB750

Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #35 on: October 21, 2015, 05:22:45 PM »
quickest, easiest is to get it all ready to come out and then get a strong helper for 15 minutes or ease it out onto some sort of platform that is equal height to the bottom frame rails...bright side to all of this is you can replace the pucks and re-torque the head gasket and you will likely have a nice dry engine (but not on the inside!) for many thousand miles
If it works good, it looks good...

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #36 on: October 21, 2015, 07:23:22 PM »
Yep. Looking forward to that. In addition, I'd like to do a thorough clean and frame/motor paint so it was coming out anyway. If nothing else, the bike is outside in the yard so I could just do the tip method into the grass if need be.
1973 CB750

Offline 754

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Re: CB750K3 pickup.
« Reply #37 on: October 21, 2015, 09:15:02 PM »
You can install a weldless frame kit, in about 2 hrs or so

I had to cut my frame on the road, when i fried one side of my camshaft... It still ran though..
 I like the color i bought a 73 same color..in spring of 76.. Still have it in pieces, tank is pretty tired looking but still original paint .
« Last Edit: October 21, 2015, 09:19:17 PM by 754 »
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #38 on: January 25, 2016, 07:18:31 PM »
Very nice, 754. I love the paint, and the only way id personally alter mine is by doing a stock colored professional paint job.

Hi everyone! Haven't posted since October when I found that the top end truly was not getting enough oil. At that point I decided to give up until I was able to have the time to work on things again. I was having some carb balance issues on my XJ and since I wanted to ride it as long as possible into the winter I focused on fixing all of that up.

It is now January and I have finally disassembled the motorcycle to the bare frame (First time doing so, wasn't all that bad! I'll definitely have some help putting it back in, however, as I believe I'll be painting it and don't want to scratch the frame/motor).



Some things I noticed it would need are new steering bearings (I'll go with all balls and follow one of the many videos online of how to swap them out). I also figured I should just go ahead and re-build/upgrade the front brake system because it's original.

But the main concern I have now is taking care of the oil problems I was having beforehand. Therefore, I'm going to order new oil jets and whatever other assorted O rings/gaskets/pucks that are involved in that area. There's a pretty thorough hackaweek video on it so I think I'm going to follow that. I look forward to all of your help!

1973 CB750

Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #39 on: January 25, 2016, 07:41:52 PM »
just so you know, the oil jets are NLA and tough to source used...so hopefully yours are still in place.  Just pull 'em out and clean them.
If it works good, it looks good...

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #40 on: January 25, 2016, 08:09:53 PM »
Noted, thanks for you help Sean.
1973 CB750

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #41 on: January 26, 2016, 12:45:54 PM »
Well we have a problem, friends. Though I was able to get every screw off of the valve cover itself without so much as an impact wrench, I was having trouble with the frontmost breather cover screw (the external triangular cover, pictured below):



Ive manage to never strip or break a screw/bolt thus far between my two bikes, but alas, the time was going to come.

Shortly after I took that picture, I heated it up with a torch, and gave it one more whack with the impact driver, and it sheared the head clean off  :-\ Any suggestions about how to get thus sucker out without doing damage? I've never extracted something like this before.
1973 CB750

Offline Restoration Fan

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Re: CB750K3 pickup.
« Reply #42 on: January 26, 2016, 01:32:17 PM »
If the head is completely sheared off, you should be able to lift the breather cover off, right?

If so, then you will be able to get to the rest of the bolt and put a pair of vice grips on it to turn it out.
Ron

Stella - Logan's Senior Project    78 750K http://forums.sohc4.net/index.php?topic=141761.0

Logan's Reward - CB500 and CB550 Cafes    http://forums.sohc4.net/index.php/topic,147787.0.html

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #43 on: January 26, 2016, 01:37:11 PM »
After doing a little more research, It appears I can go that route. (I was concerned that there may be threads on the cover itself but it doesnt appear that way, based on google images! I'd hate to get stuck this early in the teardown, which is why asked, and search wasn't helping me any.
1973 CB750

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #44 on: January 26, 2016, 08:25:31 PM »
Back again.

Used the shop manual and the Hackaweek video (in reverse order, of course) to take the valave cover/valve tappets, etc off.

I snapped some pictures. If you'll remember from a couple of months ago, I'm trying to find out why I'm not having oil shoot out of the tappet covers when the engine is running (See previous videos in thread).

The consensus seemed to be that I had clogged oil jets. the oil leaking over the front also was implied to be leake "pucks."

Now, to my untrained eye, it looked the pucks and orings were still pliable (I could be wrong, but they certainly weren't brittle).

One thing I do know, is that the orifaces in the "oil meter jets" did not seem to be clogged, which is what I believed would have prevented the oil from getting to the head.

Anyway, here are the pics. What do you guys think?

Left 1&2


Right 3&4



And the oil on the front

1973 CB750

Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #45 on: January 26, 2016, 08:29:54 PM »
you can pop them right out of there...could be plugged underneath.  Spray cleaner through them just like carb jets.  Clog could also be in the cam towers oil passages.  Lets see some pics of your cam and rockers.
If it works good, it looks good...

Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #46 on: February 02, 2016, 06:04:27 PM »
Back again,

So I pulled the oil metering jets and they really weren't clogged I don't believe. Same with the cam tower jets. Regardless, they both got a hearty cleaning with Carb cleaner, and now those parts along with the rockers/arms/cam/gear are bagged and tagged. See below:







I also wanted to take some shots of the sludge on the front of the engine, and I hope it's clear enough. Im beginning to wonder if it wasn't actually the pucks that are leaking, but the gasket between the top engine jug and the bottom (for lack of better words). Now, Im sure with a hot engine the oil is obviously going to trickle down, but if you look near the plug holes, they're not nearly as dirty as the front fins.









So...the speculation used to be that A.) I probably had leaky pucks causing the front of the engine to be caked in oil, and B.) that the reason my top end wasn't shooting oil out of it, was due to clogged metering jets and or passage jets.

What are your thoughts now?

Thanks-Nick
1973 CB750

Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #47 on: February 02, 2016, 06:29:18 PM »
take the plug out of the main oil gallery (hex plug above and slightly left of the points cover) spray cleaner into the holes where the oil jets go and make sure some exits out...might have to tilt engine various ways to keep it from continuing down to the crank.

If your pucks are not bad now, they will be in 5000 miles or so, plus it looks like you need to pull the head for new head gasket.  Sometimes a re-torque will fix that and no need to dis-assemble any further but that is a gamble because there is no way to tell until the engine is running again

What you have shown of the valvetrain looks to be in excellent condition.
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Offline BrosefStalin

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Re: CB750K3 pickup.
« Reply #48 on: February 02, 2016, 06:46:17 PM »
Thanks for the help. Yes, the Pucks and the small o rings that go around the oil jets (and along the head) are getting replaced. What's the best source for these?

Further, I really didn't want to have to take off the valves and the head, but It looks like I'll be diving deeper! Hopefully this isn't too difficult.

Ok, so once I have replaced the pucks, o rings, and gaskets, lets say that that doesn't fix the problem (I won't be able to tell anyway until the engine is back in, but that's ok).

Would it have to be the oil pump at this point, or could it be somewhere in the oil delivery lines/return lines themselves? Is there a way to even test the oil pump with the engine not mounted and running?

Thanks again.
1973 CB750

Offline seanbarney41

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Re: CB750K3 pickup.
« Reply #49 on: February 02, 2016, 07:11:44 PM »
bad news...looks like the "know it alls"(including me) have failed again.  And I personally apologize for any extra work I may have caused you...and thank you for being an excellent listener.

good news...so far your motor looks to be in excellent shape except for the head gasket leak.

Pulling the head, or replacing it, is not hard and you have done excellent work up to this point.  I can tell you are following some sort of manual, just continue doing so.

Also servicing the oil pump is not hard, although I still don't think it needs anything as evidenced by the strong oil pressure.
 

Use Honda oem for the pucks, o-rings and cylinder head gasket...probably about the same money as an aftermarket top end kit, but much better quality and at this point, you are not going to need the base gasket stuff.

Member Elan on this site sells all the parts needed for the oil pump that are no longer availale from Honda.

I feel like we have led you astray and it amazes me as everything posted in this thread is identical to two 750's I have had that exhibited identical symptoms...right down to me thinking noises were leaky exhaust gaskets.  Both ate their camshafts in very short order and both either had plugged oil jets or missing o-rings.

This thread is IT for tips, tricks, info, etc. that is not in the manual
http://forums.sohc4.net/index.php/topic,107040.0.html
« Last Edit: February 02, 2016, 07:13:22 PM by seanbarney41 »
If it works good, it looks good...