MOPED ARMY

???

Thanks for the tip - I've e-mailed them.

Yeah, let's see if we can figure this thing out before you pay someone else to do it.

First, what happens when you try to start it? Does it try to run at all, or is it just DOA?

It ran fine until you parked it? Did it rain that night?

Is fuel getting to the cylinder? Is the plug getting wet?

Given what you've said about everything you've done, it might be time to get a compression guage and take a measurement. I think I paid about $30 for mine a few years ago. Even if you never use it after this, owning it will impress your friends, and might even get you laid. If that happens, it'll take your mind off the Jawa for a while.

But seriously, the thumb thing only tells if it's really hosed big time. If your rings or bore are just plain worn, you could easily have enough compression (say 100 psi) for a thumb pop, but not enough to run, or run well. You should have 120-150 PSI.

My pleasure.

hey i could try to give you a hand some time... do you live in the city?

Keep that gauge for as long as you can, you never know...

Sounds like you've got help on the way. Great!

Let's ponder on this thing for a few minutes... You say it starts, but dies when you crack the throttle. Will it stay idling if you don't give it the gas, or will it still puke?

145 is about as good as it gets, so we can eliminate compression as a problem. That leaves fuel, air, spark.

You sound confident that the fuel system is OK, I'd just double check that fuel is getting to the cylinder by cranking the engine over for a few seconds with the ignition off, then pulling the plug. It should be wet, almost drippy. If that's the case, and you trust your work on the carb and sealing leaks, that leaves air and spark.

Air is an easy one, are you getting the same symptoms with or without the filter? Does applying the choke make any difference? Other than leaks and clogged filters, this is pretty easy to eliminate as a suspect.

That brings us to ignition, which, given that the bike ran until it was parked outside overnight, is a pretty likely culprit. Make sure the wiring and all connections are clean and tight, burnish the points contacts (use a burnishing tool, or carefully clean them with a small, fine "nail file"), Make sure all the connections to the stator plate are sound, and double check the run/stop switch. Of course, check the high voltage lead and the spark plug cap, and the spark plug.

I have a hunch that, even though you're getting spark, something is erratic in the ignition that's causing the spark to be too weak to fire the fuel/air mix.

From what I hear, just have got and air/fuel problem. If you spark is good and blue, it will be fine. Clean the points to make sure if you want. Its gotta be the air/fuel tho.

Could be an air leak, but it sounds like he's checked that already. That and the deal with it not starting after sitting outside overnight make me think ignition.

I'm curious to see what it ends up being.

get a new spark plug