I put a dyno jet kit on my 04' 400 and it runs better for sure, I then ordered a k&n filter for it and decided I should do a check on the plug to make sure it is not lean, well with a WOT pass and then killing it while still getting on it, the plug was as white as a ghost, so we went up and up and up and up, testing every time to no avail, plug was still white, Dynojet recomended 132 we are now at 144 and the plug is still white. just a little note the scooter ran like scalded dog with 140 jet in it. Please help. any input would be great, I just don't want to burn my motor up running it to lean. Thanks[img]i/expressions/face-icon-small-confused.gif[/img]

 

That is how you test a 2 stroke, I was told to get it to where it runs good, then take it for a ride, but take it easy just in case it is lean, for about 10-15 miles or so then check your plug colour, that is what my dealer told me cause I was doing the same thing with the same results. So the 132 was probably close.

 

Hey doober, well I put in the 145 jet and did a ride for about 1hr, pulled the plug it was white,
turned the air mix screw out 1/4 from factory setting, it was whiter, turned it 1/2 in from fact will run it today and see. It does run good but I didn't like the colour of the plug, so I will have to test more.
Shouldn't this air mixing screw help with minor adjustments? And ,out more fuel, in less fuel?
Also if the air mix screw doesn't help would you recommend going to the 135 or 140, or should I go up with the # of jet keep in mind I started at the 150 and the plug was black. I think I can get a 147.
On a fun side I did some water wheelies, about 20 of them I think I was signing surfing USA.
Ha Ha [img]i/expressions/face-icon-small-happy.gif[/img]

 

hey guys, I've got a silly question. Are the number sizes on the cat factory jets the same as the numbers on the dynajet jets, if so I guess im going to be going back to my factory 150 since I have increased air flow in mine with a K&N filter, or at least something closer to the 150. I rode mine around easy yesterday and did get some color on the plug, but it definently goes white if you stay in it for about 45 sec's. cya[img]i/expressions/face-icon-small-smile.gif[/img]

 

Southernmud, to answer your first ?? No they are different, by how much I dont know. And anton I have never played with the air mix screw, I just played with my jetting, that is what is the main thing I was told, I was told it will mostly do your idle more than anything so weather this is true or not I dont know, after an hour how many miles did you get on,and was your plug white or starting to turn a bit?? When I played with my jetting I put on a good 20 -25 miles then checked my plug and went from there, this is what my dealer told me to do to get the jetting right, if you notice any bogging or anything unusual, stop and check. or go back to your last jet that worked and try it a bit longer and see what happens, is what I was told, I am no pro at jetting so what I say is by no means law, it is what I have been told by my dealer.

 

I have the K&N also, thats when I noticed that the bike was off, I also had the 150 jet and when I pulled the plug it was black. So I went to my dealer talked to him about it and I was told to try the 145, and to try and fine tune it with the mixing screw. I installed the 145 and set the screw at factory two turns out. took it for 1 hr about 25 miles [took my time]. Looked at the plug white in the middle, so I turned the screw out 1/2 from factory, drove home. It was even whiter, so now I will try to turn the screw 1/2 the other way and see what happens. at that time I will see if I should change the jet or not? I know the 150 didn't work so I will defiantly have to find the right combo. I will let you guys know what happens. Hopefully my motor wont blow?????????[img]i/expressions/face-icon-small-wink.gif[/img]

 

The idle mixture screw will only adjust your off idle response and idle mixture, it will not affect the color on your plug while runing it, to do this you need more jet. I put my factory 150 jet back in today as I stuck a needle in it and the dynajet jet and found that the factory 150 was indeed larger than the dynajet 144, by quite a bit. I ran my scooter just a little bit today and have gotten a grey color to the plug, so I think Im getting close. Thanks to all for any input.[img]i/expressions/face-icon-small-smile.gif[/img]

 

southernmud, you are on the right track, how long did it take you to get the different colour on your plug, quite a while probably hey?? I think I need to put mine down a bit cause I am getting a backfire and burning way too much fuel, last year I could go 100 miles + but this year I almost polished off a tank in 55, now even working it hard I should get better that that. They changed my choke plunged and there is no way to adjust it and I think it is to tight so letting in to much fuel. Oh well back to the dealer to deal with it.

 

[img]i/expressions/face-icon-small-smile.gif[/img]yeh, I think I am almost there if not there, I may try to go 2 #'s more but first Im going to look for any air leaks, I just cant believe that dynojet's kit would recomend me so lean, they must of sent me the wrong kit or something. Thanks again

 

Hey Guys

just in case, are we talking about the same mixing screw? There is one on a cable that will allow you to ajust the idle. the one I'm talking about is at the bottem of the carb just beside the bowel.
[img]i/expressions/face-icon-small-confused.gif[/img]