fse 400 valve timing ???????
 

Hello everyone - new on here and this is my 1st post hopefully I can get a bit of help
Just replaced the cylinder head on my GG and couldnt mark anything up before stripping as the chain had jumped the pulley and bent valves etc etc anyway according to a thread I was looking at on thumper talk there should be a timing mark on the flywheel to indicate the correct TDC - well I aint got one of them , I cant even tell where the ignition pick up gets its signal from
Any assistance here would be greatly appreciated (esp with photos) I have the 15 pins between the marks etc thats all ok I am just not sure if I have set up on exhaust TDC or ignition TDC
Thanks in advence Dave

I think you may have answered your own question. TDC on the exhaust stroke is the same as TDC on the compression/firing stroke. The only thing that makes one different from the other is you or whom ever times the cam's.

The piston comes up twice during a complete cycle on intake, compression, power stroke, and exhaust.

If you can not find a TDC mark, put the piston as close as you can to top dead center. Rock the crank back and forth (by hand) and look all around the fly wheel and you will end up finding a mark on the flywheel and a dot or slash or cast line on the case it self and that would indicate TDC. Also note, sometimes you will have two marks on the flywheel, one for TDC and the other is ignition timing. When rotating the flywheel by hand in the direction of engine rotation, the first mark would be ignition and the next one that comes into play is the TDC mark.

Please note; The above is a general way of timing any over head cam shaft engine.

Ron

Does this mean that GG run the "lost spark" as do Honda etc where every up stroke the ignition fires?
This would as you say mean any TDC would be the ignition depending on valve position

Most all 4 stroke engines that use a crankshaft trigger for the ignition are the wasted spark type of system (It fires every rotation). The only engines that do not use the wasted spark, are engines that use the trigger on the cam shaft. It will fire ever other turn of rotation.

Ron

One other thing, it is possible for the camshaft sprocket to spin on the shaft if the engine locks up, the gear is only pressed onto the shaft. It happened to me when I dropped a valve (early style valve head came off while riding). I had my machine shop re-align the camshaft sprocket and then tack weld it to the shaft.