I'm an old hand at VWs and other small engines... but I'm stumped.

Kids brought the kart back from neighbors and it wouldn't start...

Found no spark. Ohmed out the coil and assumed it must be the CDI. Replaced CDI.

Started shotgunning. Replaced coil, found it was bad chinese spark plug. Replaced plug, see lots of fire at plug. No start.

Sprayed ether in carb, not even trying to start.

Checked compression. My gauge won't quite fit right, but I did see what I consider low compression... 45psi.

Checked valve clearances intake and exhaust have what I guestimate to be .004" slack. So no stuck valve. Watched both move as it cranked over.

I shot a squirt of oil in the cylinder and put the plug back in, and it didn't sound any differently.

I'm starting to think cracked piston or bent valve.

Any thing obvious I'm missing?

 

how about the "Kill" circuitry? Disable or measure it at the connector on CDI.
When you sprayed ether and it would not fire, do you know if you had spark? Most likely no, if you had spark it should have fired?

 

Well, we've got spark. Went thru and installed all the coils and CDI modules I've ended up with whilst chasing down the bad spark plug. Used it all as a teaching tool for my 8 year old son. It's not the kill switch. But thanks anyway!

Wes

 

Ether will not always fire a engine. When I was having starting issues no mater how much I sprayed it would not even try to start. But a squirt bottle full of fuel and a couple of squirts down the carb worked every time.

 

Try the above hold the throttle open give it a few squirts and see if it will try to fire. By any chance is the choke closed?

 

Just curious...did you ever figure it out?

 

No, I haven't.... I've just resigned to the idea that it has very low compression. Ya know, it's amazing when you start a project only to find that 1)your work just took to you Finland and Germany for 1-1/2 weeks, and 2) upon your return, find that your mother in law just sold her house and is moving in (as planned) within 2 weeks.

Thanks for asking though...... when things quiet down, I'll likely pop the head off and inspect things.

 

At least Germany has great Beer and with the Mother in law in the house you will want to be working on things as often as possible so I think your pretty good to go on the purchase of a Chinese quad it'll keep ya busy and away from the well no need to explain why they called a rumble seat a mother in law seat in old cars.