• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

1979 GS750 Blowing Blue smoke

  • Thread starter Thread starter ehkmcveh
  • Start date Start date
That's the base gasket. Not the head gasket. Hard to tell how high those spots are, but I'd still try to remove them as best as possible. You can use a wood chisel to get the high spots. There is no pressure inside that gasket so it's not like it has to hold back cylinder pressure like the head gasket does. Only use a Suzuki OEM gasket for the base and the head gasket. The only other head gasket I would trust is a Cometic gasket. Stay clear of cheap aftermarket sets.
 
yeah base gasket, oops. I have a Suzuki gasket waiting to go on. the spots are pretty level though. I will try and go at it some more but they are just concrete!
 
Got the cylinder mounted but ran into some difficulty installing tappet.
attached shows a lip on the inside wall where the tappet slides into. It occurred from me trying to re-align it to get it in.IMG_7674.jpg
Is there a way to smooth this out. I have some 220 grit sandpaper but wasn't sure if I can take that to aluminum.

I had the tappet in all the way but it did not move easily like the others, almost seized. I managed to get it out.
 
Doing some more reading, tappet = Shim bucket, I was reading someone suggest using 600-1000 grit sandpaper but no reply saying success or not. I have the valve springs out right now. Anyone run into this?
 
Alright.... compression question. Did some reading on the forum but still need a little clarification on my specific situation.

Just finished got the rebuild back together and having 50-70 psi readings on all 4 cylinders. Tested with the carbs off (full throttle). Once the pressure gets to the max you can basically see the gauge start dropping slowly.

During rebuild, lapped al valves with fine compound. Cleaned them up. Tappet clearances within 0.03 to 0.08mm after shim changes
Timing was done according to the service manual. T-1.4... 1 arrow flush with cylinder head, pointing forward. from 2 arrow count 20 pins to the 3rd arrow. Then put idler assembly and cam chain tensioner back on.

All piston rings were replaced and oriented as shown in the service manual.

The head gasket was NOT changed. It appeared to be made of sturdy material and I cleaned the surfaces with scotch bright. I realize that gasket is compressed and then de-compressed (during rebuild) that it loses some integrity.

The engine has not been run yet. Have read that these readings are not to be worried about until you run the bike a bit ?!?
Just wondering if you should get strong reading right after the rebuild (not ran yet), or do you have to wait a bit for it to "seal up"

Alright guys, rip into me on what I did wrong
 
Started the bike yesterday... Was doing more reading and said taking comporession test off fresh rebuild is useless until a few miles are on it.
Now start working on the carbs.... bike is doing about 20MPG
 
yep, you need to make the rings sit and get married with the cylinders shape. that's not the case before doing some km.

No blue smoke anymore? Did you measure the valves wooble?

I had a similar issue after an engine rebuild and had to disassemble / assemble the engine some times. the engine had only fex km (less than 50). I re-used the same head gasket without any issue few times, 4, 5 times. After few hundred km, its integrity started to going over. Had to buy a new one.

About my oil leak (and making blue smoke) issue on the 4rth cylinder, even if the rings were new, even if all the seals were new, the oil leak came from the only part I did not changed: valves guides.... 0.15mm radial play for the intake valve, 0.35mm radial play for the exhaust valve.....
 
Last edited:
boris.h said:
yep, you need to make the rings sit and get married with the cylinders shape. that's not the case before doing some km.

No blue smoke anymore? Did you measure the valves wooble?

I had a similar issue after an engine rebuild and had to disassemble / assemble the engine some times. the engine had only fex km (less than 50). I re-used the same head gasket without any issue few times, 4, 5 times. After few hundred km, its integrity started to going over. Had to buy a new one.

About my oil leak (and making blue smoke) issue on the 4rth cylinder, even if the rings were new, even if all the seals were new, the oil leak came from the only part I did not changed: valves guides.... 0.15mm radial play for the intake valve, 0.35mm radial play for the exhaust valve.....
Click to expand...

Yup no more blue smoke. Think I have a small leak on my oil pan (since I went it to take a look). I believe its dripping on my exhaust pipe, so when the bike engine begins to get hot it appears that the head is smoking ! Need to investigate a little more.

Have a new gasket on the oil pan so prob just need to drop it and clean the metal surfaces (scotch bright) a little better
 
Just tapped a piece of paper to the base of the bike, to capture where the oil leak is coming from the bike.... it doesn't look that bad so its not the oil pan causing the smoking.
Just had the bike started up, when it got warm it appears the smoke is coming out of the head gasket. Not really sure what that means... it doesn't smell like exhaust... almost plastic like?

I hope there is not engine damage occurring
 
You must log in or register to reply here.
Back
Top