Have you guys using 150-160 mains ever had your air/fuel ratio checked on a dyno? Sounds lean to me. The GYT-R kit instructions say 160/165 with no lid and trinity's tips & tricks says 167/172 for this set up. I'm running mine on the rich side until I can get it dynoed. Better safe than sorry. Holes in the top of the piston are no fun.

 

Ok let me get this straight, Im kinda new at this jetting stuff since all I have owned have been 4X4s. Too much air is too lean, conversely, too much fuel is too rich. Is that right? But it is safer to be too rich? So I assume if its too way too rich then it will flood out? Also, without the airbox lid gives more power since you have more air? Is the only way to know if your jetting is on is by checking the plug? If so how do you run the atv prior to pulling the plug? Is the plug hard to get to?

 

No, the plug is not hard to get to but wear a glove because you are right around your header pipes. If you do a search on spark plug check procedure, better yet here is the link, this will help.spark plug check later

 

Kyraptor23, after riding my cannondale you decided to upgrade the raptor to keep up. Hey at least you beat my dad's Z in a drag race j/k. Serious though I have rode a raptor with the yoshi and I could not tell a whole lot of difference between it and the 'dale. 'Dale may have been a bit stronger. From what I can tell the key to the raptor is the jetting. As you know after the mods to the banshee I had to remove the lid. I wouldn't think you would have to remove the lid with just a pipe and filter but the raptor is so constricted stock you never know. Later.

 

Kyraptor23... I would avoid going by what sounds good & just try different combos yourself. If you are not into wrenching then you can always pay someone to jet it for you using a Dyno. There are guys on this forum running as rich as 190-200 & some as lean as 145-150 Mikuni mains. That's a big difference & its all depends on your machine, filter, airbox mods, temp/altitude, engine mods etc. I ran rich for a long time in the 170-180 range of mains & really enjoyed the mid/top end pull but didn't realize how much bottom end I was missing out on until I rejetted with mains in the 150-160 range. Unless you run a lot of wide open trails & go full throttle all the time I wouldn't worry too much about running lean on top, if the bottom & mid run real good, then chances are the top is real close too. Also, when you get good at it, you can always jet a little on the lean side for good bottom/mid end performance & then mix a little Race gas to avoid engine damage.

However, it takes a lot of wrenching/jetting time to know when you are one size lean or one size rich to play around with things like using race gas & all. If you really want to learn, then try jetting real rich on the mains, so much so that it bogs real bad in some part of the throttle range when riding, then back off a size or two until it runs good all around. Then you can try different clip/needle positions & different types of airfilters & cutting holes in the air box & or taking off the lid altogether & you'll see that once the mains are real close, everything else has a bigger impact on jetting just like the manual/directions say they should. You'll be much happier that way. I admit it's real time consuming changing out the main jets more than once so just leave the fenders off until you get it right, you'll be an expert in no time. I actually jetted so much that I broke some of the stock carb parts, but as a result, I can diagnose & rejet in less than a half an hour so it was time well spent.
Good luck!

 

Thanks a lot Chimmer, excellent information once again.

Chris, its about time you show up. Ive been wondering where youve been. You off for break now? If so we need to go riding! You did beat me on your dale but only by a few lengths if i remember right. But I was stock and you werent hardly stock with the pipe and remapping. Once I get the yoshi on, well, lets just hope the dust doesnt bite you too bad. Nah just kidding with ya, but we do need to go riding if it warms up a little.

 

Ky ahh I see you bought a Yoshi, well I got rid of my Graydon Proline and too bought a Yoshi. Don't recongize the name do ya. You'll figure it. I am running 160-165 mains, try your needle in slot 3- or 2 i tried 4 buit that was a no-go. @7.5 on the pilots with my airscrews turned out 3.25 times. I live about an hour from you so our elevation shouldn't be that different. this should work. Cut the front of your snorkel off and put the lid on I recomend it, It is wet in our part of the country this time of year, trime the insid eof your snorkle also. Here is somerthing else you can do to help destroy the cannaturd, when you adjust your clips under the black caps: after you unscrew the caps there is a long spring, cut one coil off it! better throttle response and less turbulance also. Not hard actually simple. I got mine dialed in last night she runs good. more low end than my graydon. mid about the same, she doesn't pull as long up top but I feel it is a better all around pipe. Graydons are for Built motors!!!!!!!!! Huge headpipes, I mean huge.

 

Nice to hear from you again. Did you not cut any holes in your lid? If youre ever this way, you should definitely ride with us or at least stop by, not hard to find. I plan on putting the pipe on probably thursday and doing the jetting. What do you mean by 7.5 on the pilots? I believe Im a retard when it comes to this stuff, but I am new at it. That cannondale wont be any problem when I get dialed in. He only beat me by 2-3 lengths on gravel about 600 ft. and it was no contest on blacktop, he couldnt get took off with that frontend standing straight up on him. I thought the raptor was light in the front! Thanks for the info, you have been a real help!

 

I ment 27.5 pilot jet numbers. Need any help walking through the jetting process email me. Mmal00@aol.com I'll give ya the number to call. When I installed this pipe I put my lid back on, But I will be taking it back off so I can squeeze just a bit more top end rpms out of it. Use an outerware lid , that way you don't trash the stocker by cutting it up. You might need it for a rainy ride. This pipe has lots of low end. My first thought was that it wasn't much quiter than my G/P but after riding it it is a little bit quieter, but it has a good sound to it.

 

Thanks a lot for the help, Ill definitlely email you if I have any problems. Are you goin to have to increase your main jets when you take your lid off? Or do any needle or pilot changing?