I had 2" snorkels on my '03 650 but after a day of riding it wasn't running right and I got sick of the increased belt noise. So I am going back to the stock snorkels. The one thing I always had problems with was the popping and dying at idle. Will leaving a shim in the needles help this? A .4mm shim = .015". I have 4 of these and had the needles shimmed to .8mm with the snorkel on and it idled great. I didn't notice any power increase and actually noticed a top speed loss. So back to stock and no worries, hopefully. Anyways, does it make sense to shim the needles slightly with stock snorkels at about 1300' above sea level?

Thanks.

 

Hey whereis
I am far from being any kinda carb wizard--but I am getting a bit of an education---go to yahoo or any search engine and type in any carb related word and read the interesting links--seems harley uses a keihin carb very similar to mine on the 360---I have found out that your needle in no way should effect your top end at wot---the needle controls everthing from above idle to about 3/4 throttle then the main takes over. it is also permittable to shim a needle up to around .060--
I have been doing alot of experimenting with my carb lately, and have found out my best top speed on a 200' steep hill with the same running start everytime is achieved with a 150 jet. Stock jet was a 155 and even with my mods, the 150 jet gives me a better mph. Buttttttttttt--my midrange is the best with a 165 main, but bike breaks up real bad at wot.

I tried cutting my needle spring down 1" in hopes of richening up the midrange while still using the 150 jet, but bike is bogging real bad on low end.

Ordered a new needle spring today(to replace the one i cut) and two richer pilot jets---I also found out that to a small extent, the pilot also feeds fuel up to about mid throttle.

I am going to file some brass washers for shims in different increments after I get my new parts and start with the .060 shim and work backward in .005 increments to attempt to keep my top end speed at maximum (with the 150 jet) and to try and get all the midrange this little machine has to offer,

 

Sounds like you needed pilot mixture adjustment. The low, mid, and wot settings overlap, and at wot you are still getting fuel from the idle and midrange circuits. This is detailed (with graph) in my service manual.

 

Hey Pman

any chance of posting, e-mailing, or faxing me the graph??? I would love to see it--I probly wont have my peices parts until late next week and it would give me something to think about

 

Not quite sure how to do it- far newer to computers than mechanics. I think I saw one on a website somewhere, I will try and find it for you. Will try to post something tomorrow. I actually found a good graph in my Daughter's Pred. 90 svc. manual.

 

thanx pman
be lookin forward to it

 

Haven't got the graph up yet, but you might find these interesting. Duncan Racing and Carb Tech andKeihin