Rebuilt Engine, Now Crank wont fully rotate

B

BrianHlozek

New Member
Hey guys, this is my first post here, seems like a cool board with a lot of great people. I replaced the head gasket on my GS425 recently and re-assembled the engine according to the manual. Unfortunately when trying to turn the bike over with the crank it only makes one full rotation and then locks up. Its odd because both cylinders reach the top of the cylinder head, and then it locks up after that. I also have the clutch lever taken off the engine and was thinking that it could be contributing to the lock out.
 
Are you sure you have the camchain lined up properly? If you're one link off, the piston could be hitting a valve.
 
I guess I could have miscounted which would be throwing the timing off, but I counted it several times and it was correct everytime. It has nothing to do with the clutch being depressed though does it?
 
I don't have a 425, but I do have a GS. My GS850 has electronic ignition, and TDC is NOT at the top, but 90 degrees to the left, or 9 o'clock. Dunno if this offers any help, but when setting your cam chain on the cams properly, if you're not on TDC, yer screwed. Of course, if TDC is not at the top, you may very well be setting things incorrectly. With my GS, the two electronic sensors are to the left and right of TDC, so I had a heck of a time figuring that out, as it wasn't in my Clymers.

Just so ya know.

loudest143
 
Yeah that could be it. According to the manual if you align the "T" to the timing mark on the engine for the right cylinder this is TDC, if thats not actually TDC then I'm screwed. I'm gonna go mess around with it and see what I can come up with.
 
Just got done fixing it. The problem was it was off TDC right by a millimeter or so, so that when the cylinder was plateauing it was running into the exhaust valve which was just barley starting to open. Anyways I corrected the problem. Oh, and in order to verify that it was in fact TDC i just looked down the spark plug whole, no manual necessary. Although it did end up lining up with the TDC mark under the starter cover.

Thanks for the help dudes.
 
Now you just have to cross your finger that the valve isn't bent. Check compression after your all done.
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light
    • www.jadusmotorcycleparts.com
    www.lostapostle.ca/
    www.sparckmoto.com

    Spread the Love

    Back
    Top Bottom