MOPED ARMY

Is the jetting correct for your setup? Compression testers have a tough time getting an accurate reading on small displacement engines (they often read low).

Fred's Guide is a great place to start for basic troubleshooting.

What carb did you get as a "new carb"? What was wrong with the old carb that needed it replaced?

You may need to do a leak down test to see if you have an air leak causing problems.

Also what air box is on your carb?

Stock garelli usually has a 14\12sha on them and a stock air box that has a good space for still air to get in and be pulled into the carb. They usually have something like a 51 jet in them. Replacing the exhaust would mean you may need to upjet a little. Also a different airbox\filter may need an upjet as well.

The original was a 12sha and I took it all apart and ordered a rebuild kit. I cleaned everything and put it back together. Put it back on the bike and no luck. So I figured I have wasted $40 on worse and bought a new one. The exhaust is just the OEM configuration nothing performance. I have tried different jets. I have tried starting it with the air filter on and off.

If the gasket that seals the two halves together is shot, would that cause a decent drop in compression?

No it is not plugged at the motor, as a matter of fact I cleaned all that up with a Dremel. I then soaked and cleaned the tube that heads into a brand new muffler. I was referring to the case gasket. Both head and cylinder gaskets are new w

A bad case gasket could cause an air leak or transmission fluid leak, depending on where it's broken, but I don't think it will significantly affect compression.

Like, crankcase pressure could be lowered (again, depends on where the break is), but once the piston is past the ports, that won't make a whit of difference.

You should fix it though, hah. (edited)

Lotsa times on a garelli or your girelli the stator side crank seal goes bad. Just take a couple large screwdrivers and pop the dizzy off.

Wait... get the correct puller and do it right. Change the other side too while u at it. Use nd30 fluid.

I am not sure if someone mentioned it, but air/fuel mixture can cause running problems. I got my Garelli eureka flex running good by removing a few of the screens in the carburetor air filter. Those filters come new with multiple layers of screens and can be easily removed to adjust the air flow........Anthony

were you able to figure out what was causing your compression issues? having same problem with my 78 garelli