Forum

[Count Johnny]

Your thoughts gentlemen please. As pre previous posts, 1996 500. New distributor with points and condenser. New coil. Now has a temporary battery (fully charged). All properly timed to 10 degrees BTDC. Nice strong spark. Carb was previously passing fuel from the float-bowl drain, so was stripped cleaned out and re-fitted. Fuel first turned on the the carb was inundated with fuel, so refitted the old needle valve. Carb now weeping from the float bowl drain. Numerous attempts to start with only a half a dozen bangs over the course of a morning and nothing in the afternoon. The 'bangs' didn't seem like the usual 'I'm about to start if you give me another swing' but more like a gun going off in the exhaust. Strangely, although later in the day the carb was still leaking from the float bowl, we were getting zero bangs and the plug was staying dry. In desperation, we even tried taking the air filter off and trying some EasyStart - nothing. Stuck my hand over the inlet port and felt suction. Could it be carb, exhaust valve, something else? They've now taken away my shoelaces and put me on suicide watch so any thoughts would be appreciated.

[Beezabryan]

Timing 180 degrees out ie timed on wrong TDC, exhaust instead of compression.

[Norm]

Timing is too far advanced and have you set it on the compression stroke? Static timing .8mm before TDC, virtually TDC compression stroke

[Barry_Q]

I'm with Beezabryan on this one. I made the same mistake when I rebuild the engine in my Lightning. The symptoms were exactly the same as you describe. I simply turned the cam plate 180 degrees and all was well.

[Count Johnny]

Thanks chaps. I hope that's the case and will re-check it today. TBH, I think I've got it right having watched the inlet pushrod rise and fall (while feeling for TDC with my trusty screwdriver) and noting that both pushrods span freely at that point.

[jaffa90]

If the spark plug is dry after numerous attempts there`s no fuel getting in, fair enough some fuel could be fired on the exhaust stroke as said (180*) with a good spark. I would be looking at the slow running jet.

[Count Johnny]

Gentlemen. As I suspected, we had correctly timed the engine on the compression stroke. Well, sort of, because unfortunately (because I am very stupid) I had it vaguely in my mind that the cam in the contact breaker span counter clockwise, so we were setting up the points on the right hand 'heel' of the cam, rather than the left - thus a lot of degrees out, but not 180. Having realised our mistake, it started first time. Sorry to have troubled you.