Animalman294 Posted May 17, 2005 Report Share Posted May 17, 2005 I am doing a few mods right now and am not sure where to start for my jetting. I have Toomey T-5's, Noss head 20cc domes, lightened fly wheel, Delta 2's, and a K&N, and a Dial-a-jet. I don't want to buy a whole kit, because you usually only use a couple of sizes anyway. So what size do you guys think I should start on with my main jet, pilot jet and what position for my needle valve? I am going to be riding at Sand Mountain NV 4000 feet mostly, and otherwise around my house at 200 feet. I already plan on running a 50/50 mixture or straight AV gas or race gas if a friend can hook me up. Thanks for the help........ Cheers Quote Link to comment Share on other sites More sharing options...
2stroker Posted May 17, 2005 Report Share Posted May 17, 2005 If you already have a Dial-a-jet I don't think you need to buy anymore jets. I thought the main pupose of having one was to have the ability to richen or lean the A/F mixture without the need to change jets. Unless the jet size you need is outside the range of the Dial-a-jet. Quote Link to comment Share on other sites More sharing options...
Banshee~ Posted May 17, 2005 Report Share Posted May 17, 2005 320 mains, 27.5 pilot, middle clip is a good starting point. I think a dial-a-jet is to change the clip position. Quote Link to comment Share on other sites More sharing options...
sredish Posted May 17, 2005 Report Share Posted May 17, 2005 I think a dial-a-jet is to change the clip position. 370357[/snapback] Noooo... The dial-a-jet sucks fuel in from the bowl and disperses it into the air/fuel stream. The "dial" adjusts how much fuel it gets... It can adjust 10 main sizes I believe, 5 up / 5 down Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 17, 2005 Report Share Posted May 17, 2005 In that case, I'd go 300 mains. 350 to 250 mains in your case is more than enough adjustment. From near sea level to 4000 feet is about 2 main sizes...MAYBE 3 at most. At 4000 feet elevation and 20cc domes, I don't think You'll need AV or race gas...but, Dave Noss can tell you for sure...he's da man. Quote Link to comment Share on other sites More sharing options...
Animalman294 Posted May 17, 2005 Author Report Share Posted May 17, 2005 Thats exactly what I am wondering. Because you only have five adjustments and you are supposed to be jetted in the middle of the range. That way if you go up in elevation you can adjust for the elevation, but if you go down in elevation you can again adjust for the change. I am just trying to figure out where to start from. I think I only have to re-jet if I change the flow of air (ie. reeds, pipes, filter, etc.) Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 17, 2005 Report Share Posted May 17, 2005 Get your mods done first. They have the biggest voice in the jetting scheme. Once you have your jets dialed in for your mods, then...you slightly adjust them for either temperature and/or elevation changes. For example.... When I put pipes on my quad, it had to go up about 8 sizes on the main. Now that it's warming up...I'll probably have to adjust the main one size...two sizes at the very most and twist the air screw a tiny bit. You are half correct on your last statement. You do change jetting when you change air/fuel coming in or air/fuel coming out. But, as pointed out, you also change jetting with temp and altitude changes. Quote Link to comment Share on other sites More sharing options...
Animalman294 Posted May 18, 2005 Author Report Share Posted May 18, 2005 Ok, so dial it in after the mods are done, and then fine tune it with the dial-a-jet. I still need a ball park to start in with the mods that I am adding. So 300 mains, 27.5 pilots and the needle would go to what, the second clip from the bottom? What about the air screw adjustment? Should I back it out a half turn or how do you determine this? Jetting.................... Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 18, 2005 Report Share Posted May 18, 2005 Are you using Toomey's jet kit? If so, it's the dynojet needle...longer than stock. Put the clip in the 4th position, or...4th groove down from the blunt end. The dynojet needles have 6 grooves. The stock needles have 5. If it's the stock needle, leave it in the middle. Correct, 300 main, 27.5 pilot. I'd turn the screws out 1.5 turns out from fully seated, go from there. I have stock reed cages with boyesen reeds... I don't know what VForce reeds do to the needle...so, might want to read up on that. Quote Link to comment Share on other sites More sharing options...
Animalman294 Posted May 18, 2005 Author Report Share Posted May 18, 2005 No I don't have a jet kit and I am not sure what the dyno jet needle is. I am still using the stock carbs with the stock needle. I was going to buy a kit, but I was told that unless you change your motor configuration a lot, you won't use half of the needles that come in the kit. So I was going to go and buy 300's and 27.5 pilots (or is that stock) and start from there. Then if I have to go up or down I will buy the next jet. I just thought is was kind of a waste if you have the whole line of jets and never use half of them, ever. Thanks for all your help......... Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 18, 2005 Report Share Posted May 18, 2005 (edited) No problem. I just bought mine in February, off a good friend. Jetting was way, way off. I just went through the whole setup of jetting my stock carbs. I also have a very similar setup as yours. I'm planning on having boonman mill my head, much much cheaper than a NOSS head for now. Sure...I'll get one soon...but, other things to buy for now!! 25 is the stock pilot. They go up by 2.5. So, 27.5 is the next size up. Honestly, my air screws are at about 2 to 2.5 turns out right now. I'm going to put the stock pilots back in, and try 1 out on the screws. When I first started jetting, it was consierably colder out...so, that might have been what I needed. Now that it's warm, I have 330 mains and 27.5 pilots. It was a tad rich this last weekend, in 70 degree weather. I'm going to bump down to 320 mains and TRY a 25 pilot again... It looks like you have a K&N inside the airbox, no? If so...these numbers are a little rich for you... I have either K&N Pod filters or the Toomey 2:1 foam filter that I run, no airbox. Good luck!! I'd get about 4 sets of plugs, just so you can get 'er dialed in!! Edited May 18, 2005 by dajogejr Quote Link to comment Share on other sites More sharing options...
sredish Posted May 18, 2005 Report Share Posted May 18, 2005 I have a very low opinion of the Dynojet needle. I see quite a few peeps that have trouble getting their machine dialed in with that needle. They'll go back to the stock needle and the problem goes away. Needles are awfully touchy things to be swapping in and out. Not saying there aren't some that should be, but it should be something that's tested for not just done overall, IMO anyways.... hey, what do I know.... Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 18, 2005 Report Share Posted May 18, 2005 I hear ya. I bought the whole kit from Magic for 30 bucks...normally 50 or 60. I would take them out and put the stockers back in...but, it runs just fine with those needles...After getting it with a thumb, putting on a twist, putting in new needles, and going back to a thumb...I've had the tops off all I can stand so far. If I couldn't get her dialed, I'd switch. They're running like a champ...so I'm gonna leave. You're right though...no need to do it just to do it!! Quote Link to comment Share on other sites More sharing options...
sredish Posted May 18, 2005 Report Share Posted May 18, 2005 I would take them out and put the stockers back in...but, it runs just fine with those needles... "If it ain't broke, don't fix it." Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 18, 2005 Report Share Posted May 18, 2005 Easy to say...but hard to practice indeed.. Quote Link to comment Share on other sites More sharing options...
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