Jetting Question

[Oregon Duner]

I have an 86 lt250r. I had 210 main jet and i just put an fmf pipe and took the airbox lid off so I put a 150 in. I went wot in 5th gear then killed it and coasted to a stop and the plug looked dry like it had never been put in. After normal riding the plug is black. It sounds and runs like its a little rich. I also have a 240 and 230 main jet. What do you think?

[88lt250racer]

With more air flow from your mods you should have to go up on the main to richin the mixture rather than going down.

[Kane]

I imagine he mistyped the 1 on the 150.

Try a 230 and possibly a slot to raise the needle one step.

[Oregon Duner]

ya my bad i ment 250. Why would it be dry though and did i do the plug test right?

[Kane]

Because it's a tad rich not soaking rich. Plus, if the plug is pulled as late as 5 minutes after shut-off the heat can evaporate much of the unburnt fuel that may be left on a plug from a rich condition. When doing a plug test it's best to get the plug out of the engine as soon as possible for the most accurate reading.