Gs750 Back fires and wont start

[tom203]

Here's a pic with crank mark on TDC for 1-4. Compare to yours or take/post pic of your actual setup. Note the notches on camshaft ends facing each other.I don't see how the intake camshaft could be that far off as valves should strike pistons then.

[Tysonhatfield]

So this is what I got when I pulled the valve cover off image.jpg

[Crank]

Looks like there was water in that motor!

[Tysonhatfield]

Should I just scrap the motor? And look for a new one or is it cheaper to do a rebuild? I'm only in the bike $150

[tom203]

For the sake of science,inspect intake rocker arms for damage ,correctly reposition intake camshaft, doublecheck valve clearances and see what happens . I'm still surprised that intake valves did not bump pistons being this far off.

[hannibal]

If valves hit a piston, I could be a mess. But it's worth correcting that cam position and seeing if it'll run. The gactory manual has a good explanation. Looks like the PO went 40 pins (or 20 links) between the 2 and 3 marks.

[Tysonhatfield]

Thanks for all the help Everything looks ok other than rust on valves im going to try to clean them up a little and put it all back to spec and see what i get

[Tysonhatfield]

So I finally got it all back together got the timing right cleaned all the rust and crap out, put it all backed together tried to fire it up and i now have no compression so i thought i might have done something wrong took it all back apart rechecked everything from sevice manual all specs and everything was right on put all back together and same thing no compression so my question is would it be cheaper to rebuild it or just try and find a used one thats running any suggestions Thanks.

[tom203]

At the start of this thread, you had compression, so you, yes you, have made a booboo in your correcting of camshaft to crankshaft setting. With crank at TDC for 1 and 4 , camshaft notches in ends should be pointing at each other and mark 1 should be parallel to head surface and pin count 2 to 3 should be 19. Then look at the signal coil for 1 and 4 - the little tab that spins on advancer should have just spun by that signal coil to trigger igniter.