won't start

[Happy Daze]

I admit to having done the dumbest thing, well not quite ever but i won't go into that. Thing is, i bought a very cheap non runner (yes) Savage (yes) that i thought would make a tasty little forties style thingy. One of the first things checked was the coil, which had failed, even though i was getting a weak spark. So instead of getting a new coil straight away, i ploughed on. Much cutting welding and of course, rewiring (yes,and to be really smart, all in black) later, i put the coil in to find a weak spark and no go. To be fair the spark is much better, but still looks a bit iffy. The carb is ok and i have two cdi's and two decomp controls. While checking the decomp lifter and head gasket(renewed) i spotted a fairly worn cam. Could this cause a failure to start? I have seen some fairly worn cams come out of running engines and would rate this a 7 out of 10. I myself have never come across an engine not starting because of the cam. Just to go back to the rewire, I am competent an have done about half a dozen bikes, but with this one i done away with the side stand and clutch switches and went straight from the cdi to the kill switch. Any help on this would be greatly appreciated. Thanks for getting this far.

[bullet350]

if the components for the timing (sensors & pick-up) are located on the top-end then i'd double check these to make sure the timing hasn't been altered when the head was off. if they are on the crank then assume they are ok, for now at least.

the other thing to check is the cam timing in relation to the crankshaft.
i marked up a cam sprocket and flywheel on an xt660, then put it back together using different marks that were also on the parts. this meant the spark was fine and at the right time, and it sounded 'right' on the starter but didn't go.
in the end i just kept moving the sprocket one link along the timing chain until it ran.

also check the valve clearences.
on the same xt660 after removing the head and reassembling it the valve clearences had totally disappeared. the exhaust valves were slightly open when the motor should have been sucking in through the carb. the engine was just drawing air from the header pipes and then trying to burn it.

bring back push-rods!

bullet350

[Steve Lake]

mmmm i'd go for timing.....but be very careful when playing with valve timing, on my srx6, which has a high comp piston and yoshi cam, if the valve timing is out, then the valves WILL contact the piston, personally I'd turn the engine over by hand (with the plug out) pencil down the plug hole....check for TDC, at one TDC all valves will be closed, the next TDC will see the exhausts just closing and inlets just opening. also make sure there is some compression, and FRESH fuel

[Happy Daze]

Thanks guys sounds like good advice, on the other hand it's sunny and i just picked up an sr500 which does run, so it may be some time before i get back to it.