need to rejet after mud lid.

[swabber30]

ha guys i have been on here asking theses stupid questions and i still can't seem to get the answers. i have bought and installed the twinair powerflow kit and mudlid. my bike still won't run right on the top end. it is a 07 bute 750. i have a pro ciruit pipe and a dyntek. and snorkeled the cvt. it idles fine and runs good till i crack the throttle wide open then it falls on its face. i tryed proping the one corner of the lid up and took it for a run and it ran better so i think it is not getting enough air. so if anyone can help on what jets a guy should run or any other thing i should try to help this issue. also there is poeple out there saying that you don't have to rejet with twinair, i would like to know what set ups there running to see if i'm running somthing diferent. thanks for the help guys.

[NMKAWIERIDER]

<div class='quotetop'>QUOTE (swabber30 @ Jul 26 2009, 09:52 AM) <{POST_SNAPBACK}></div>

ha guys i have been on here asking theses stupid questions and i still can't seem to get the answers. i have bought and installed the twinair powerflow kit and mudlid. my bike still won't run right on the top end. it is a 07 bute 750. i have a pro ciruit pipe and a dyntek. and snorkeled the cvt. it idles fine and runs good till i crack the throttle wide open then it falls on its face. i tryed proping the one corner of the lid up and took it for a run and it ran better so i think it is not getting enough air. so if anyone can help on what jets a guy should run or any other thing i should try to help this issue. also there is poeple out there saying that you don't have to rejet with twinair, i would like to know what set ups there running to see if i'm running somthing diferent. thanks for the help guys.[/b]

Hi swabber30, I see you are running a snorkle on the CVT and I assume you have sealed-off the stock air intake for the box so all you have is the mudlid for intake. That should be close to the stock air draw as long as the prefilter is clean. Using the twinair doesn't require rejetting, but increasing the exhaust flow with that pro ciruit will require some jet changing but first lets take a step back. 9 times out of 10 with the Dynatek CDI, you will need to increase the slow circut's fueling ability by using the #40 pilots and then a slight increase on the high circut ...not enough to rejet, but enough to use shims under the needles of the CVs. Most go with .040. This will remain a constant with the CDI, but know we have had one that this didn't help. His probably had high float levels or something that most don't have.

So, now going forward, the pipe lets exhaust out easier and reduces back pressure. This causes more volumn to be pulled in from the intake side...but wait!, with the restriction the airbox has, this causes the engine to develop more vacuum across the asorators which pulls more fuel up from the bowles...hmmm the engine should run richer and richer as the RPMs increase intil it get so much, it starts flooding out. You say you cracked the corner of the airbox to let in some additional air and this helped. How much? Lets go a step farther. Lets place two smashed cigarett butts under each corner, with duct tape tape down the center firmly and go for a run. If it runs great, then I would go down about two main jet sizes. If is isn't as good as it was with just one in one corner (and you will want to test this), then just one size would be my suggestion. One other test though before you settle on anything. With the lid closed and locked down, with duct tape, cover about a quater of the mud lid's opening and take it for a run. If it is way worse, we are going in the right direction, if it runs better...we need to re-think and talk some more later. OK?

Let us know how it does with these tests.

[VTprairie]

the needles should be shimmed whether he has the dyna or not and the 40 pilots don't always work. He mentioned that it was fine low and mid but falls on its face. the thing is there has been more done then just the lid which can cause havoc, from the sound of it he is rich, you may be close by 2 jets lower but we need to find out if he is using dynojets or stock needles and what size is in there.
Swabber30 fill us in a little more

[NMKAWIERIDER]

<div class='quotetop'>QUOTE (VTprairie @ Jul 26 2009, 03:47 PM) <{POST_SNAPBACK}></div>

the needles should be shimmed whether he has the dyna or not and the 40 pilots don't always work. He mentioned that it was fine low and mid but falls on its face. the thing is there has been more done then just the lid which can cause havoc, from the sound of it he is rich, you may be close by 2 jets lower but we need to find out if he is using dynojets or stock needles and what size is in there.
Swabber30 fill us in a little more[/b]

Your right VT. We need more info Swabber30, like what jets are in it now, who's are thay ie Dynojet/Keihin, and does it have any other Dynojet parts like needles or springs in it, what's your elevation, where in the RPM range do you start to feel a problem, what color are the plugs burning and are both doing the same....stuff like that. Give is the low-down on your machine.

[swabber30]

i have the stock jets and stock needles, everthing with the carb is stock. now when i proped the side of the lid up and took it out it ran fine and i pulled a plug and it looked good, but when i just had the lid on and took it out the first time it was good till about 3/4 trottle then it was poping and backfireing. then i pulled the plug after that and it was rich the plug look wet and sooted over. the plugs are showing the same. i don't know what else i can tell that i haven't all ready. but another question if i doo shim the needles what does a guy use or should i buy a jet kit. i'm not sure the advantages to these kits, so maybe a guy could explain that to me. if i have left any info out let me know and i'll try to fill it in so i can get a diagnoses. so i can get back out on the trails. the elevation is 2200ft above. thank guys and hope to here soon.

[VTprairie]

I didn't shim my needles I have a kawi mechanic that works cheap so I just pay him. Don't buy the kits stick with stock jets. Being that high I have no clue for jetting. but it does sound like your rich. Did you plug the front intake?

[NMKAWIERIDER]

Well I am just going to take a stab at it and say that in the stock configeration, Kawie recommends droping one jet size after 3900 feet. If you were stock, and I mean completely stock, we wouldn't be talking about it, but you aren't with the pipe and lid so... I think the pipe increased the flow rate enough that you may very well need to go down a size already at 2200 feet. Now for the mud lid. Slumlord and myself...and my math-wizzard wife.. deturmined that the total square inch opening of the mudlid and the stock box intake was very slightly different. In most cases, not enough to notice, but on some touchy applications, it might show up.. more then just noticable. To see if yours is one of those, take the mudlid and the prefilter off the top completely and snap it on leaving just the open hole in the airbox lid and take it for a run. Let us know what the result is. Do this as is...with no jet changes.

[swabber30]

<div class='quotetop'>QUOTE (NMKAWIERIDER @ Jul 27 2009, 01:43 AM) <{POST_SNAPBACK}></div>

Well I am just going to take a stab at it and say that in the stock configeration, Kawie recommends droping one jet size after 3900 feet. If you were stock, and I mean completely stock, we wouldn't be talking about it, but you aren't with the pipe and lid so... I think the pipe increased the flow rate enough that you may very well need to go down a size already at 2200 feet. Now for the mud lid. Slumlord and myself...and my math-wizzard wife.. deturmined that the total square inch opening of the mudlid and the stock box intake was very slightly different. In most cases, not enough to notice, but on some touchy applications, it might show up.. more then just noticable. To see if yours is one of those, take the mudlid and the prefilter off the top completely and snap it on leaving just the open hole in the airbox lid and take it for a run. Let us know what the result is. Do this as is...with no jet changes.[/b]

ok i will try that and get back to you tomorrow. and by the way i did block off the stock in take hole.

[VTprairie]

is your pro circuit a full exhaust or just a slip-on if its just a slip on it is not breathing enough either, most slip ons you don't need to rejet.

[swabber30]

<div class='quotetop'>QUOTE (NMKAWIERIDER @ Jul 27 2009, 02:43 AM) <{POST_SNAPBACK}></div>

Well I am just going to take a stab at it and say that in the stock configeration, Kawie recommends droping one jet size after 3900 feet. If you were stock, and I mean completely stock, we wouldn't be talking about it, but you aren't with the pipe and lid so... I think the pipe increased the flow rate enough that you may very well need to go down a size already at 2200 feet. Now for the mud lid. Slumlord and myself...and my math-wizzard wife.. deturmined that the total square inch opening of the mudlid and the stock box intake was very slightly different. In most cases, not enough to notice, but on some touchy applications, it might show up.. more then just noticable. To see if yours is one of those, take the mudlid and the prefilter off the top completely and snap it on leaving just the open hole in the airbox lid and take it for a run. Let us know what the result is. Do this as is...with no jet changes.[/b]

ok guys i took the lid apart and ran it with the open hole and it ran like crap poping and no power so i think its to rich, now i covered about half the opening and then tryed it and it seem to run better now i don't know which way this will effect the jetting. i pulled the plugs and they seem to be light in colour but not to bad. my exhaust is a slip on i think, i got a new pipe that runs from the back cylinder but kept the stock one that goes to the front. let me know what you guys think of them results. thank you