Difference in mixture between cylinders?

[N736RA]

So this morning (another coldish one here in Maine) as the bike was warming up I noticed that smoke from the exhaust seemed to be mostly coming from the front pipe (in that as it warmed, the smoke from the rear stopped well before the front). First question here is, does that mean too rick or too lean (I'm guessing rich?), and the second question is which way do I adjust the a/f screw (if thats the solution) to solve that, OR does it not matter?

Thanks!

[jer0177]

Was it "smoke" or condensation? Smoke is black or blue or grey. Condensation is white.

[N736RA]

Originally Posted by jer0177

Was it "smoke" or condensation? Smoke is black or blue or grey. Condensation is white.

Condensation, that was the word I was looking for, but yes, it was condensation. I figured it might be a tell that the front cylinder takes longer to warm up for whatever reason.

[jer0177]

That's because the front pipe is longer and yes, takes longer to warm up.

[N736RA]

Originally Posted by jer0177

That's because the front pipe is longer and yes, takes longer to warm up.

Well, that makes a remarkable amount of sense, clearly I didn't look for the easy solution, thanks!

[jer0177]

Originally Posted by N736RA

Well, that makes a remarkable amount of sense, clearly I didn't look for the easy solution, thanks!

You're welcome. That being said, it is common (in air cooled machines) to richen up the rear cylinder as the richer fuel mix aids in cooling the jug. There is a washdown concern there though.

I live by this:

Occam's razor - Wikipedia, the free encyclopedia

[93gc40]

Originally Posted by N736RA

So this morning (another coldish one here in Maine) as the bike was warming up I noticed that smoke from the exhaust seemed to be mostly coming from the front pipe (in that as it warmed, the smoke from the rear stopped well before the front). First question here is, does that mean too rick or too lean (I'm guessing rich?), and the second question is which way do I adjust the a/f screw (if thats the solution) to solve that, OR does it not matter?

Thanks!

Sounds normal too me. Longer pipe has more room to build condesation and take longer to burn off.
AS far as the AF mix. Leave it alone until you aquire a Service Manual. Lots of things affect AF mixture it idle and you NEVER adjust the AF mixture screws or jets "because" of an issue at cold start-up. AF mixture is only diagnosed and adjusted with a fully warmed up motor. A Cold motor is a time where you want a VERY rich mixture. And is adjusted via the CHOKE. If you are lean at start-up, A choke is out of adjustment.

Yes the mixture requirements can be different between the cylinders, especially in a Vtwin. The cylinder in front tends to run cooler then the one in the rear, AF mixture is used to balance the combustion temps. This is not as big a deal with Waterpumpers, but even some Shadows run a rich rear jug AF screw is adjusted in to lean out to richen. Unbalance AF mixture requirements can also be due to engine condition. UNsynchronized carbs can also appear as Lean/Rich in one cylinder.