2001 Road King carbureted. Stock 88 cubic inches. Stock cam, I think.

When I start the bike, and ride it for the first couple minutes and the choke is on, it seems to pull better. When I push the choke all the way in, it seems to be less powerful/responsive.

Overall, it runs good, however, I believe my carb may need a larger jet size. Just wanted to make sure that I should start with the main jet.

Will I need to consider changes to the needle valve too?

Planning a 98 cubic inch install this week.

 

The slow jet should be bumped from a 45 to a 48 and the mixture screw adjusted using the lean drop procedure. But if you're doing a 98" kit the point is moot anyway.

 

Main jet only kicks in at WOT so it's pretty useless at low rpm. Low rpm is all about the jet needle and slow jet.

 

Here are my plugs.

?

?

 

Front is on the left.

 

Plug readings are useless in determining your jetting needs unless you've isolated each individual carb circuit. As mentioned before, if your intention is to increase displacement then Id think it prudent to jet up across the board.

 

Concentrate on the low speed(low air speed) circuit first, them move to the main.
Do not be surprised to see as much as a 50 pilot, is certain cases.
Make sure your air/idle screw is out, about 2 1/2 turns from bottom.
Scott