mcncoic

Here is a question that I have not been able to find an answer to on the site. I am starting to rejet my stock carbs for pipes and filter mod. I have read just about every article about jetting and think I got a pretty good idea where to start at. With going from stock jetting 200 mains to say 280-350 (for example) will the factory needle still work or will I have to get a larger one? The pipes I got from a friend (FMF Fatty) the silencers need to be repacked. The K&N got off ebay but no jets. I have seen jet kits come with needles so this is why I ask. I don't plan on buying a kit just the jets (mains&pilot). Any help?

oldturtle, I found out which style pipe that I have is. It a FMF Fatty. I got it from a buddy. In an early respose you mentioned different size jets with what I have which size do you think would be a good starting point?

RV00GT I just installed the Pro Flow adapter for the K&N and a K&N along with a different intake. You could also put on a Boost Bottle. Just remember that you will need to rejet with the different filter. This site has some outstanding articles on rejetting. Take a look at them. Depending on your riding conditions it up to you whether you want to take the airbox lid off or just punch holes in it. I was able to get the K&N and adapter plate on ebay for about half the cost of new.

Thanks oldturtle for the help will let you know how things go as I start to work on this issue. Gotta try and find some different jets now. Do you happen to know where I could get some different sizes to include the pilots? Once again thanks for the help. Ronnie

oldturtle What I did to the airbox was take about 1 1/2" out of the center. Then I cut some plastic strips from what I cut out and used them to hold the two halves together. The lid I did modify. I sits pretty nicely on top. The BOSS Racing intake is pretty nice it eliminated the need for the boost bottle. On the pilots how can you tell what number they are? Are the numbers stamped on them somewhere? You say that the 400-420 might be too large could I use the needle clip position help change this at all? The Yamaha shop here locally sucks. Put it this way I asked them the same questions and they wanted to sell me a $140 power up kit that could or could not have the right size jets that I need. Didn't say anything about doing a plug chop. I have had the shee since it came out of the crate and now getting around to doing some mods on it. I have no problem at all doing the hands on stuff but need some help with the knowledge of how it really works. Jetting throws me for a loop sometimes. I guess it the same concept as a holley just smaller parts. Thanks for the insight. Anybody else that can help I am always listening.

This is my first post so bare with me. I have a 99shee with a BOSS racing intake (its like adding 1/2" spacers) that has a built in crossover tube, K&N filter w/adapter plate, stock everything else (including carb jetting). The airbox I had to modify so that it would fit the factory bolt holes to allow the engine coolant overflow to remain in place. The airbox now has a 1" gap around the sides and bottom and no snorkel. I was still able to put the airbox lid on but can only use the back locking tabs. Here is the problem: the motor seems to bog down once I go past half throttle in any gear. Runs strong and hard up to that point. I was told that I need to rejet the carbs (but what size mains? I got some 400, 410, 420s on the way. Is this too big?) It has more power than I had before I did the mod. I also plan on putting different pipes but unsure what brand. Another problem that happened was that the motor seemed to run away while stopped. It started to rev up and would not stop. I was able to lower the RPMs by putting it in gear and trying to stall it. But as soon as I bumped the throttle it would stat again. It had been running fine until then (it would start and idle fine before this last time) Anybody out there that can help it would save me some headaches. Thanks Ronnie