Checking valve clearances help!

[Guest]

Hello,

First off thanks everyone for all the info; this forum has given me a lot of info to help me along the way. I'm rebuilding a 1979 GS1000 and sent the frame and parts to powdercoat. At the same time I decided to rebuild the top end and this is where I ran into some issues.

I got everything back together and followed all the instructions from the Suzuki Service Manual. Last night I went to check the valve clearances and can only turn the crankshaft about half a turn. Then it stops like something is blocking it... Not sure what this could be but I'm hoping that someone has an easy answer.

Thanks guys in advanced

[tkent02]

Sounds like you got your cam timing wrong, a valve is open while a piston is up, it hits the piston and blocks the engine from turning. Recheck your cam timing.

[nathanmaus]

Alright I'll check it again, I am almost positive that I did it correctly though. If after I check that and it's done correctly, is there anything else you can think of that may cause this?

[Nessism]

I agree that it sounds like cam timing.

[tkent02]

There's nothing else in there, unless you dropped in a bolt or something.

[DimitriT]

It's not in gear, right?

If you take out the plugs you should be able to see which pistons are approaching TDC (the inner or the outer) and it should be apparent if the valves for that piston are closed or open.

[nathanmaus]

Definitely didn't drop a bolt in there... That being said it's stored in my friends garage and his kid likes to mess with things so that's not completely out of the question. It's not in gear, checked that and I'll pull the plugs out and try that.

Just to double check my work, this is what I did. I'll check it again when I get the time tomorrow morning.

Lined up the T mark with the timing mark.
Lined up the Arrow "1" on the Exhaust sprocket with the Cylinder head, leaving the "2" Arrow pointing straight up.
Counted the roller pins, starting with the one directly above the "2" Arrow, towards the intake sprocket.
Lined up the "3" Arrow with the 20th roller pin.
Bolted the camshafts down.
Mounted Cam Chain Tensioner.

These were the instructions I followed via the Suzuki Service Manual. Is there anything I missed? I'll go over it again.

[tkent02]

Sounds right, as long as you used the correct T mark.

[Nessism]

Sounds right, as long as you used the correct T mark.

Yes, there is both 1-4 T and 2-3 T.

[nathanmaus]

Ok I thought there was only one T mark so that's probably my issue. I'll redo it and let you guys know how it goes.

[Chopperjake]

I was (am?) having a similar issue where it would only turn over half a turn. I think my cam chain was binding up at the crank. (although I concede I'm not as knowledgable as a lot of these guys on here). Is your cam chain tension correct? See my thread called "cam chain slack" for pictures - I'm not smart enough to post a clickable link, sorry.

[nathanmaus]

Thanks guys, looks like it was on the wrong timing mark. Now I have a bigger issue. Apparently the torque wrench that I was using is broken and doesn't work on low ft/lbs. So I over torqued the cam holder bolts and ended up breaking 4 of the 16 bolts in the head. So I'm having it looked at to see if they can be backed out. If not, does anyone have a line on a 1980 GS1000 head? And I know my signature says it's a 1979, but one of the POs must have replaced the engine because it has the CV carbs on it.

Thanks again guys.

[gustovh]

I have one, if you need it.

V

[Chopperjake]

Why do you think the engine was swapped out and not just the carbs swapped out?

There should be a serial number on the engine that you can look up to tell you what year it is.

Just throwing my $0.02 in there so hopefully you don't end up with a top end that doesn't match up....

[nathanmaus]

Chopperjake: Because the 79 GS1000 came with VM carbs which are smaller than the CV carbs that are on my bike right now. I want to say that the VM's are 26 mm and the CV's are 32 or 34mm so they wouldn't fit on a head from a 79.