gs 450t no compression help please

[Guest]

I have no compression do u think it may be because I knocked it out of tim when I replaced gaskets from crank case up . Second question is there any thing in the crankcase that will cause no compression . When I got this bike dude said he had no idea what was wrong with it so I'm stuck . Any help or info will be greatly Appreciated and ty for ur time . And I've never got it to turn over even before I replaced gaskets and seen it had no compression . I have the service workshop manuel but it's not helping me trouble shoot no compression .

[tom203]

So it's never turned over for you,and you have replaced gaskets from crankcase up?? You need to check camshaft to crank timing- do this before trying to turn over anymore. Should all be in workshop manual. There are marks on camshafts and crankshaft that MUST be aligned. Here's a typical layout....image.jpg

[Robbiem1961]

Have you no compression on either cylinder?, are the plugs fitted with sealing washers and torqued down, take the spark plugs out and see if any valves are bent and stuck open, check the valve clearances. These are lovely little bikes, simple and easy to work on

[Oldman99]

This is a pic of my spare head from an 81 gs450l. Front of the bike would be to the right.

First make sure the cylinder closest to you is at top dead center. Make sure you have all the slack out of the cam chain on the front side of the engine and drop the exhaust cam in so the (B) is at the top{has a #2} and the notch on the end of the cam (A) is flat with the valve cover matting surface.
Tighten the cam caps to 6.5-8 ft.-lbs. (these bolts love to snap) the cam lobe on the side away from you will be pushing down on the valve so take your time. Next is to set the intake cam in with 18 cam chain pins between (B) and (D). After the cam caps are tight and you reinstall the cam chain tensioner is when the chain loves to jump one tooth forward. It might take a few trys.
When your done. Turn it over by hand and make sure nothing hits. Stop when the closest cylinder gets to TDC and (B) is at the top. Make sure the notches are still lined up and that there are still 18 cam chain pins from (D) to (B).
Should be good then.