Thread: Engine not starting

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I was working on another project of mine and I can't get it to run. It's actually a '78 cb750, an old motorbike that I rebuilt and it ran great last year. I figured you guys would be able to figure this one out before I go joining another forum.

I was testing the plugs for spark so I put a plug into one of the leads and turned the engine over, nothing. When the side of the plug touched a bolt I got a good strong spark. Shouldn't the plug spark without being grounded against the engine??

I'm trying to figure out where to go now as I've checked everything else over the last three days and I'm ready to burn it.

Thanks,
Sean

I had the carbs apart as that was my first suspect. The floats moved freely, and I blew through them (tasted aweful) seemed clean. I did notice something funny that I wasn't sure was normal. When I turn it over the carbs suck in and blow out through the intake side, wasn't sure if that was normal either. I wondered if I adjusted the valves wrong or put the cam in wrong when I had it apart?? It wasn't starting before I did that though.

Thanks Denny,
Sean

Thanks again Denny,

I figured I did something wrong when I felt the carbs blowing out. Back out to the garage.

I love these old things,
Sean

I finally got it running, with some problems. I had the cam out by 90 degrees, I don't know how I got that far off, I guess I was rushing. Now it's running but it revs really high, I thought it was the carbs but that didn't help.

Once again gonna check the valves, the repair manual doesn't make sense. If I follow it it tells me to adjust the valves when the tappets are up on the lobes. It says to watch until number one just starts to rise and then align the 1&4 mark to the "T" and then adjust, this puts them up on the lobes.

I seem to be getting closer

Sean