I Think My jetting is messed????

[DeadLastRacing]

Well I installed my pipe and uni filter in the winter time and now that the weather is getting warmer I think my jetting is messed? My quad sputters when I have in pinned in every gear. Right now I m running one up on both the main and pliot. Should I go up another main?

 

[jasonp]

if it sputters or misses at wide open throttle and higher rpm then go down on the main until this goes away. on the other hand if you are coming on to full throttle and the engine bogs or dies then it's lean on the main.

 

[yamarider]

Yeah, sounds like your main is too rich.

 

[DeadLastRacing]

What is a needle clip and what should that be set at?

 

[DeadLastRacing]

Normal to run so close to stock with a uni and full exhaust? More and more I keep thinking that my carb is wack, but I'm still learning. Thanks in advance for the help guys.

 

[madcow]

Is your elevation high? If it is then it's OK. The needle clip is a small e-clip than determines the height of the needle, it should be in the middle groove.

 

[yamarider]

Normal to run so close to stock with a uni and full exhaust? More and more I keep thinking that my carb is wack, but I'm still learning. Thanks in advance for the help guys.

Those jet kits are on a completely different sizing scale than stock mikuni jets which is one of the reasons I hate those jet kits. A 148 dynojet sounds ridiculously high for only intake and exhaust, after you run it a while check your spark plug and see if it isn't black on the end from running too rich.

And if the quad was jetted in the winter, it's tuned for that cold weather, so of course with the wamer, less dense air, it's not going to run as good as it did in the cold. At a minimum you need to rejet twice a year if you ride in the summer and winter, otherwise it's not going to run right half of the year.

 

[madcow]

Where did he say he had a dynojet jet? But yea, 148 dynojet is really high, I bought mine with a 150 dynojet and the plug turned black after only 1 ride. I also needed to go down a main for the warmer weather.

 

[DeadLastRacing]

I don't have dyno jets, I have some that I bought from the Yamaha shop. Like i stated before I'm running one up on both main and pilot. I go back down to stock main and see what that does for me. Where is the needle clip located at in the carb, Ill check if its clipped half way.

 

[madcow]

The needle is in the slide. You need to take the top cover off, then undo the 2 screws under the lifting arm and pull the slide out.

 

[DeadLastRacing]

Dyno jet questions........I took apart the carb that my little brother was running before he bought his eldle crab and it had a 138 jet in it (no other numbers of letters), Is this a dyno jet? I ran fine with a baffle-less stock exhaust. Is it comparable to a stock jet if it is a dyno jet? Can I use it?

I need to fix my jettin by friday, I going down to wellsville this weekend.

Could my problem be my fuel screw? Wheres that at?

 

[madcow]

Well it sure isn't a Mikuni jet. Dynojet numbers are completely different from mikuni numbers, so I don't know how to compare them. The fuel screw is near the float bowl, on the bottom.

 

[blonka]

KEIHIN DYNOJET MIKUNI
92 92 85
95 94 87.5
98 96 90
100 98 92.5
102 100
105 102 95
108 104 97.5
110 106 100
112 108
115 110 102.5
118 112 105
120 114 107.5
122 116
125 118 110
128 120 112.5
130 122 115
132 124
135 126 117.5
138 128 120
140 130 122.5
142 132
145 134 125
148 136 127.5
150 138 130
152 140
155 142 132.5
158 144 135
160 146 137.5
162 148
165 150 140
168 152 142.5
170 154 145
172 156
175 158 147.5
178 160 150
180 162 152.5
182 164
185 166 155
188 168 157.5
190 170 160
192 172
195 174 162.5
198 176 165
200 178 167.5
202 180
205 182 170
208 184 172.5
210 186 175
212 188
215 190 177.5
218 192 180
220 194 182.5
222 196
225 198 185
228 200 187.5

 

[jasonp]

KEIHIN DYNOJET MIKUNI
92 92 85
95 94 87.5
98 96 90
100 98 92.5
102 100
105 102 95
108 104 97.5
110 106 100
112 108
115 110 102.5
118 112 105
120 114 107.5
122 116
125 118 110
128 120 112.5
130 122 115
132 124
135 126 117.5
138 128 120
140 130 122.5
142 132
145 134 125
148 136 127.5
150 138 130
152 140
155 142 132.5
158 144 135
160 146 137.5
162 148
165 150 140
168 152 142.5
170 154 145
172 156
175 158 147.5
178 160 150
180 162 152.5
182 164
185 166 155
188 168 157.5
190 170 160
192 172
195 174 162.5
198 176 165
200 178 167.5
202 180
205 182 170
208 184 172.5
210 186 175
212 188
215 190 177.5
218 192 180
220 194 182.5
222 196
225 198 185
228 200 187.5

DUDE, totally awesome thank you!

 

[madcow]

That's amazing, but just to warn you, dynojet needles don't play nice with mikuni jets. When I had a dynojet needle it would always richen up like mad around mid throttle, if I moved the needle to try and clear that up it would be too lean everywhere else.

 

[DeadLastRacing]

Thanks for the list.....kicks ass........

 

[yamarider]

I've seen that chart before and to me it seems completely backwards. Being that a dynojet jet is richer than a mikuni of the same number, how is that chart possibly right? Maybe I'm looking at it wrong, but according to that chart, every jet that comes in a dynojet kit for a warrior is leaner than the stock jet... I remember the dynojet kits to range from about 126-146 if I remember correctly, and the dynojet equivalent of the stock main, according to that chart, is about a 154. What am I forgetting here?

 

[madcow]

Yea I think you're right. Mine had a 150 dynojet when I bought it and it was so rich that the plug became black in less then 30 minutes. Right now a mikuni 147.5 is right on the spot for jetting, 150 is a bit rich.

 

[blonka]

I dont know if its rite or not. I just remembered seeing it on the jets r us site so I posted it here.