Loud clicking after top end rebuild

[leedando]

Hello,

I have a 1978 GS750 that needed some work when I bought it. I've rebuilt the top end as the exhaust studs were stuck in the head and needed some expert removal! I have rebuilt the top end, according to the manual (I think) but when I turn the engine over using the kick start lever there is a loud metalic 'click' coming from the top end somewhere. The engine was running ok before the top end rebuild.

The only things that have happened are: -
- Removal/replacement of the front camchain guide
- Removal/replacement of the head
- Removal/replacement of the valve guides (refitted in the same order)
- Removal/replacement of the camshafts and cam chain guide
- Reset the cam chain tensioner.

Any suggestions or ideas of what might cause this would be greatly appreciated.

Thanks
Lee

[rgierer]

Haveyou checked vavle clearance/adjustment. That may well be the noise you describe.

[leedando]

Thanks Robin,

I've not checked that yet. I'll try this over the weekend and see what happens.

[rgierer]

When I put a new head gasket on my 1100g I made a real effort to put the shims up in a manner that I would know where they went. Despite my best efforts I had to sort out a couple of shims after the bike was reassembled. It went smootihly and addressed the engine noise in a very straight forward manner. The hardest job I had was finding a feeler gauge small enough.

[Suzuki mad]

When you put the (new?) camshafts back in did you line them up right as per the timing marks so that you are not a tooth out on the chain? This would give the sound of valves hitting the pistons!
If assembley was correct then I would go with the shimming. A old camshaft will need different sized shims to a new cam shaft due to the wear factor on the cam lobes eg a different gap. Did you replace with new originals or after market/high lift cams shafts?
Whip the rocker box off, set the engine up as per the book on No1 piston and check where the camshafts are. Then check the gaps.

Suzuki mad
Want to be riding but it too cold here!
1981 GS1000E
1983 GSX1100ESD In little bits.

[IanFrancisco]

top end noise

I had one that was driving me nuts until I did the ol' "screwdriver as a stethoscope" trick. Putting the handle on your ear and the blade on various parts of the engine will pinpoint the noise for you. Turned out my noise was coming from the blasted vacuum petcock that's been giving me grief lately. It ruined a new diaphragm in about 500 miles. Rattles back and forth so much that the thin metal washer around the plug in the center of the diaphragm self-destructed and possibly damaged the diaphragm, which was leaking so bad the motor wouldn't idle, and of course the plug was fouled from the rich running.

[earlfor]

Sounds like the cam timing is off, or a valve is not seating.

Earl


[QUOTE=leedando]Hello,

I have a 1978 GS750 that needed some work when I bought it. I've rebuilt the top end as the exhaust studs were stuck in the head and needed some expert removal! I have rebuilt the top end, according to the manual (I think) but when I turn the engine over using the kick start lever there is a loud metalic 'click' coming from the top end somewhere. The engine was running ok before the top end rebuild.

[leedando]

Thanks

Thanks for the replies everybody. They are the original cams that have been replaced rather than buying new ones. I'll check all of the cam timing this weekend and then the valve clearances and try again.

Much appreciated as I can't wait to get it going.