'83 650 Katana

[repoman]

My bike has a lean condition when I check the plugs. I took the carbs off and checked all of the jets and needles, which were what stock calls for. It does have a after market exhaust "Yoshimura" 4 into 1. I do believe the exhaust will run hotter/lean, how much bigger should I go with the main jet, 1 or 2 sizes?

Thanks

[Dave8338]

That one has potential. Have you done a full soak and clean of the cars? This would be the first place to start, if not. Also...I've change out stock exhaust several times and have NOT had to bump the jets. Jet needles yes, but not the jets.

In a lean condition, you need to find out WHY the intake mixture is lean. Usually it means TOO much air. Start hunting down possible air leaks but FIRST be sure that the carbs are spotless. This can't be done with just a can of carb cleaner...

[Nessism]

What kind of air filtering does the bike have? If you are using pod filters, I recommend a jet kit from a company like Dynojet. Getting the bike to run properly is not as simple as just changing the main jets.

[mcloud]

...Have you done a full soak and clean of the cars? ...

You can start with mine. It's the charcoal Altima there in the back...

[repoman]

This is a picture of filters.

[Dave8338]

You can start with mine. It's the charcoal Altima there in the back...

NOt a problem...break things down and mail it out. You pay for shipping!