MOPED ARMY

Well In the moped world, white smoke usually means you’re burning transmission fluid and there’s a leaky seal from the trans to the crank case.

But, this is a moby. I’m going to assume the smoke is normal 2 stroke operation. Depending on what oil you use the smoke can be white, commonly blueish and sometimes even purple depending on the oil.

I would address the exhaust leak if it is still leaking. I usually like to buy several exhaust gaskets for a bike just incase. There are few things more excruciating than waiting days to do a fix on a 2 dollar part.

Nice work! Sounds like it’s gonna be a good bike.

Smoke should be dull gray but can be white if the engine is still cold as it's producing alot of condensation in the exhaust until it's warmed up.

Best to do a leak down test, I put a Moby case together once and very carefully done, and leak tested it on the bench and found a leaking seal and had to replace it.

I use Permatex copper RTV on header coupling nuts and header to pipe joints. It holds up to the temps and unburned fuel mix and doesn't require that the nut be so tight to seal. The joints come apart easily and it can be cleaned out easy enough if and when a teardown needs to be done.

NICE Ranger 7 by the way !!!

Because of the size of the BIG nut on the exhause it needs to be check tight when the engine is heat soaked. With the engine cooking hot you should be able to get it to seal properly and it will not shake loose. The thread damaged you read about is usually from the nut shaking loose and eating the threads from vibrations and not overtorque.

Do not use any sort of sealant as a substitute for good mechanical practice and there is no need for doubling up the exhause gasket. That can cause more leakage as well as reduce the number of threads the BIG nut is grabbing in the cylinder.

IF-when you decide to go pipe shopping, a PUG big nut pipe will fit closer to the serie 7 engine angle than a Moby pipe will, but you will still need a welder friend to adjust the angle so it fits goodly to the bike. You will also want to change out the carb for something that is not a Gurtner, as there is limited sizes of jets available and you will need to rejet for the pipe. SHA14:12 would be a straight trade, SHA14:14 will fit but you need to resize the ID of the intake to 14mm (it necks down at the middle of the pipe) and make sure you get a cable choke not a lever. Lever will work, but cable is a better choice in my opinion because you can feather the choke if you are leaning out while testing/developing by riching up the charge a bit.

Hey Rebel Moby!

Thanks! Attaching another picture of the Moby, as well as my attempts to attach the Ninja G3 I bought before realizing it doesn't fit the Model 7 well...

I bought it with a Sha 15.15, and sadly the previous owner opted to get the lever choke which I've found extremely annoying so far, wish it was a cable...

The overly rich mixture could also be connected to the other forum post where you suggested my jetting is way too high.