Possible front cylinder overheating 2002 VS1400GLP

[Rockdoc]

Hi all y'all,

I'm finally riding my 2002 Suzuki VS1400GLP. After replacing the handlebars with lower handlebars that I'm more used to it really improved my riding enjoyment. However, since I've been riding it I've come to notice a disturbing thing with the bikes engine (front cylinder to be exact).

Based on the white spark plug coloration, the front cylinder is running lean. In addition, I'm beginning to get light yellow discoloration on my front exhaust pipe. None of this is happening on my rear cylinder, the plug is a light brown in color and the exhaust pipe has no discoloration. I'm thinking that if the main needle valve (the one that's lifted up and down via vacuum pressure) were lifted (adjusted) a little higher it'd give me a slightly richer mixture and make the front cylinder run cooler. I'm assuming the carburetor can be adjusted in that way (similar to the SU carburetors that the Brits used).

I'm asking because the bike runs pretty well as is and I don't want to mess that up (let sleeping dogs lie). With that said, I don't need to burn a piston or valve from it running too hot. However, I have to figure that someone on this board has had a similar issue.

Thanks in advance for any guidance you can give me.

Steve

[Herb]

Raising the needle might solve the issue.

The problem is that these needles don't have multiple settings. You will have to shim it. There is a plastic piece at the top and a washer at the bottom. I swapped them and it works great.

[Lechy]

First try adjusting the idle (AF) setting then check the rubber boots for cracks.

[Rockdoc]

Thanks for answering my query about my potential overheating problem. I'm going to be gone for a month, but when I return I'll take another run at the potential overheating problem I've been having. BTW, all the answers I received make sense and bear looking into. I'll report what I eventually learn.

Steve