So as I had my carb apart a couple months ago I noticed that my aftermarket mixture screw was shorter than my factory one. I also think I remember seeing some else mention this fact on here as well. Anyway So am I correct in thinking that when I have my screw turned the 1 and a half out or what have you, that it is actually further out than the aloted 1.5 turns of a factory screw? If this is the case has someone gone through and made the calculations that state that .5 turns out on a scotts screw is actually 2.5 turns out due to the shortness of it. this would be helpful when trying to guage what pilot jet is needed. Or am I completly way off base here?
Logic is fine- I'll confirm your concerns It is fairly well established that aftermarket fuel screws are cut slightly different than the stock Keihin fuel screws- so your end result being different than with the stock fuel screw is likely. However, there is no conversion guide for this in terms of this such as 1 turn =1.5 turns. You may very well need a different pilot jet. I am a bit suprised that you notice a difference visualy from the threads down (to tip) on your extended fuel screw. The Scotts should be a reliable piece being brass by most peoples standards. Here's a good guide for your Pilot circuit: Eddie Sisneros01-14-2006, 11:52 AM Seems like the most common jetting issue that comes up are pilot circuit related.the following is a sure method to choose the needed changes. With the bike warm and idleing turn the fuel screw in till the idle drops/misses.then go back out till the idle peaks/smooths. This should happen between 1 and 2.5 turns on a fcr carb If you end up at less than 1 turn you need a smaller pilot jet.more than 2.5 you need a bigger pilot jet. Choose the appropriate size and retest.
This has been my experience as well. I use a flex jet screw and my settings are typically 1/8 to 1/4 turn less than the OEM screw at corresponding temps/conditions.
Thank you for your posts. I need to get a few carb items anyway maybe I'll include a new fuel screw in my list. Doubt this will promt anyone to make a conversion chart. Again thanks.
Ill be working on my carb soon enough. Ill start a thread and document my R&D flexible fuel screw. anyone is welcome to post up what they find on their own afterarket fuel screws.
