Does a lean mixture cause bluing in exhaust pipes? I understand it happens when the metal surface is scorching and, usually, there isn't a heat shield, but I asked a guy at a dealership and he told me bluing is unavoidable no matter what. I don't believe him.

I'm going to rejet and replace the air filter with a K&N one.

Unless you have double wall pipes... they are going to blue, its just how fast they do it.

Personal experience with probibly 6 sets of pipes on the same bike over the last 27 years I have owned and ridden it. And yeah... I've been through 5 different cabs over those years too.

THe original carb was crap... don't even remember what it was... Bendix?

S&S dual throat... crap, SU... worked nice but sensitive to heat sinking,

Late 80's Kehin CV - custom jetted this myself, couldn't buy the jets I needed at the time. Not a powerhouse... but a nice carb.

Super-G, what I've been running the last 18 years.

My bike is a 2005 Intruder 800 with 5,000 miles all from the previous owner--who left his bike in the rain or rode through deep puddles, everything has rust. 5,000 seems really quick for my exhaust to blue. It's only on the back cylinder too, the front exhaust is okay.

I just took out the spark plugs and replaced them with new ones, I don't really know how to read them, but the one from the back cylinder looks like it has carbon deposits. I'm getting the carbs cleaned and jetted tomorrow.

I do have another problem. As I already mentioned, the r-tard who owned the bike before me let this bike sit outside in the rain and water got into the gas tank creating a few, small, rusted areas. I just cleaned and lined the inside with a sealer, but I couldn't seal the collar because it's too hard to get to, it's still bear metal and has some rust. What can I do to seal the collar without having to reseal the whole tank again?

Reading sparkplugs is never all that easy.

THe conditions of how you run it and exactly when you read them mean everything. But what you are looking for is "tan" , white typically neams its too lean... black obviously means its too rich... you look at the deposits, condition of the electrode, etc. Even then its only going to get you in the ballpark.

As far as your tank rust issue... I've not had to deal with that... the tanks I've done I took the extra time to deal with at the time I sealed them. But I will admit I've not worked on the one you have.

Odd symptoms as the rear cylinder usually is the one that runs hotter because the front cylinder gets more and cooler air. Assuming air cooled engines. Not as much an issue on liquid cooled engines.