rebuilt twin smoking

The smoke color isn't really the issue here even though it might help to point at the system that has a problem.

I'd rig up a leak down tester and listen for air leaks as the next step. You don't need a leakdown tester to hear where it's leaking from - just a hose that will screw into the plug hole and will take an air hose on the other end. Set the cylinder to be tested at BDC and apply air pressure through teh plug fitting and listen for hissing from the ports or the barrels. If the rings are allowing much past, you will probably feel a strong wind from the oil filler plug or engine breather hose. You will also be able to hear a loud hiss as air passes the rings.

All engine leak, some. What we are listening for is a ring pack that isn't doing its job.

Repeat on the other side and compare notes.

Of course it could just be those new rings in old bores getting bedded in.

You said in the first post that it's only the left side and the plug smells of gas. Before you tear the motor down, are you sure that the carbs are perfect, float levels spot on, no leaky floats etc

I'd double check the carbs again just to be sure they are OK

It's best to do a leakdown at top dead center compression.
Both valves are closed and if rod is dead vertical it won't try to turn motor (HD have 'problems' as rods are offset to pins but that doesn't affect 99% of motors)
Don't use more than 100psi

teazer said:

Of course it could just be those new rings in old bores getting bedded in.


You said in the first post that it's only the left side and the plug smells of gas. Before you tear the motor down, are you sure that the carbs are perfect, float levels spot on, no leaky floats etc


Yeah my carbs were set perfect before I tore the motor apart


I'd double check the carbs again just to be sure they are OK

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Yeah my carbs were set perfect before I tore the motor apart, but when I put the motor back together my left carb was leaking gas from the float over flow. I just figure it was a stuck float needle so I popped the bowl off and checked everything out, seemed Ok. Finally got some day off tomorrow so I gonna tear into her a bit and see what I can figure out.
I did do a quick compression test on both cylinders yesterday and got 140 on my right cylinder and 120 on the left. I also ordered some new valve stem seals today so Ill install those as soon as they come in and see if it helps at all.