I have an 02 660 and I had someone re jet the carbs but it doesn't run like it did... i had 155/160 jets in it and the guy working on it said it was too rich and went to 144/146 dj.. I have a DG exhaust and K&N with no lid, geared at 12/41 valves were adjusted, choke fixed. One thing is I never need to choke it??? starts right up and runs. At idle it seems to have a surge in it, the exhaust had paperwork with it when I got it and it said with the exhaust, K&N with a 4x5 inch hole cut out of it and the baffles taken out of the tube to run 150/155... Screws are turned out 3.5 i think. please help... thanks

 

If it runs poorly after the fellow worked on it, can't you take it back to him....and have him re-do the job? Stock jetting is 140/145....and thats with Mikuni Jets. The DJ jets are of a different numbering system. Go back to the Mikuni 150/155 jets and run it, then check the plugs. The 3.5 turns out is alot, however, that could be the reason the choke is not required.

 

If he didn't do it right the first time, why would I want him to do it again... this isn't something that I can't handle I just need to be pointed in the right direction. You recommend 150/155 like the exhaust suggest? What about the pilot? I see everyone talking about putting a 25 pilot?? With the 150/155 how many turns should I do? Thanks

 

Because you paid ( I'm guessing ) for it and may not have gotten your moneys worth . If you want to make it easy on yourself, leave the pilots stock, install 145/150 Mikuni jets in it, and replace the air box lid, set the mixture screws to 2.5 turns out, and ride. The mixture screws don't have anything to do with the 150/155 main jets....only the idle circuits.

 

Here's a cross reference guide for jets. Once you get it running good at WOT, then you can play with the pilot jet. If it's boggy at 1/8 to 1/4 throttle, maybe 1/2 throttle, pilot jet is too rich, if you get popping and a slight backfire when you totally let off the gas coasting down from speed, then the pilot jet is too lean. Lastly, install a wideband O2 to monitor A/F, then you can tune perfectly. I have an AEM one on my Arctic Cat.