How can it still be too lean?

[TrxTex]

Im running with no motor mods but I have a full Yoshi pipe...K&N w/outerwears and no lid. I have a 195 main in and the plug is grey...with a few black splotches around the rim. On top end its sputtering out but it rips all the way up and then dies off. The weird thing is that Im at 3600ft elevation. Im pretty sure that the 200 is the largest main. Any ideas? Should I try some needle adjusting? Also....Im ordering a Hotcam stage II this week....will that make it worse?

[jeepeater347]

Try it with your stock rev box I belive that the after market one you have doesnt work with the TPS and will give too much advance on top end

[fab410]

I had the same problem I cut a hole in the lid just like the HRC hit and run a 180 main but im under 3000ft. I also had the K&n and outerware.

[Killdmycobra]

Originally posted by TrxTex
Im running with no motor mods but I have a full Yoshi pipe...K&N w/outerwears and no lid. I have a 195 main in and the plug is grey...with a few black splotches around the rim. On top end its sputtering out but it rips all the way up and then dies off. The weird thing is that Im at 3600ft elevation. Im pretty sure that the 200 is the largest main. Any ideas? Should I try some needle adjusting? Also....Im ordering a Hotcam stage II this week....will that make it worse?

Sounds like you might actually be running rich up top? What is fuel screw set at? What needle are you running?

Jeff

[TrxTex]

The fuel screw and needle are in stock position....whatever that may be. Im also running 108 octane.....I guess that could come into play as well.

Jeff....Im curious....what makes you think it might be rich up top? I thought the grey/white plug meant lean mixture. I ran it wide open and killed it...coasting to a stop...then I checked the plug...it was dry and greyish.

[dtzalba450r]

185-190 main jet, 4th position on the needle, 2 1/4 -2 1/2 turns out. Do you run a knn filter?

[DirtDevilBT]

If it sputters as you accel than it is normally rich. If it pops real bad on deceleration or when you let off the gas that too lean. I think this is right, or the other way around not sure. But the plug shouldn't be white and not brown. It should be a very light tan, sounds close to what you have. Do you have to run 108 fuel with the CDI, 91 works just fine up to 11.5:1 compression then you start to have problems.

[Killdmycobra]

Originally posted by DirtDevilBT
If it sputters as you accel than it is normally rich. If it pops real bad on deceleration or when you let off the gas that too lean. I think this is right, or the other way around not sure. But the plug shouldn't be white and not brown. It should be a very light tan, sounds close to what you have. Do you have to run 108 fuel with the CDI, 91 works just fine up to 11.5:1 compression then you start to have problems.

If he is running those junk CDI boxes, it could be advancing the timing way too much up top causing the top end lean issue.

[TrxTex]

It was doing it before I put the cdi in. I just put that in on friday. I made a few test runs without it and then with it. It did get a little worse when I put the cdi in. Is the SRP CDI really a P.O.S.? This is the one I bought.

SRP CDI (http://www.magicracing.com/product.asp?itemid=689&catid=home)

[Killdmycobra]

From what the experts are telling me, yes. The only good ones out are the vortex which gives no power gain over stock, just lets you rev higher. and the dyna cdi has not come out yet

[911]

as your altitude goes up you loose oxigen so u realy might be rich. i'm at 500ft and a 180 with clip down 1 pos on the needle works mint for me. if it pops when u let off go out 1/2 turn on the air screw (in front of bowl) good luck:D

[TrxTex]

Here is another thing I forgot to mention. I have the full Yoshi pipe and its the Stainless one. Reading the instructions on jetting it said to try the 180 with no lid. I did so...but it also said if the pipe started turning purple then its running hot and I should richen my jetting. Thats what led me to the 195...it seemed to be fine for a while and I thought I was hitting the rev limitter on the top end. Turns out I was fouling way up top. Im going to try the 200 just to see what happens. If it gets worse...I'll drop to the 190. Also...when moving the needle up and down...what exactley is that doing to the mixture? I guess Im confused a bit.

BTW...thanks for all the input.

[jeepeater347]

Maybe the 180 was fine and your pilot is lean. Before I changed my pilot jet my header would get really hot when idling

[TrxTex]

What pilot jet did you use? Anyone else changing theirs?

[jeepeater347]

I went with a 50 or a 52

[400exrider707]

Originally posted by jeepeater347
Maybe the 180 was fine and your pilot is lean. Before I changed my pilot jet my header would get really hot when idling

Exactly, sounds like the main is too rich. You should have richened up the pilot to eliminate changing pipe colors! Usually when your running 3/4-full throttle your moving pretty quick and the incoming air is enough to keep the pipe from glowing. So you should try messing with your air screw/pilot jet and drop the main down some.

[FAQ654]

Yeah I would start with a 50 poliet and a 185 main if it was me. Maybe even try moving the clip down 1 slot on the needle. Just my 2 cents.

[86GN]

Why are you running 108 octane? Are you having problems with detonation?
The higher the octane the slower the burn soooo if you don't need it don't use it. It will lower your performance and carbon everything up since its not burning completely.

[DirtDevilBT]

Originally posted by 86GN
Why are you running 108 octane? Are you having problems with detonation?
The higher the octane the slower the burn soooo if you don't need it don't use it. It will lower your performance and carbon everything up since its not burning completely.
Yeah, when you use higher octane you must be able to condense it enough for when the spark plug fires. If it's not squeezed, like in high comp pistions, it may not burn all the way and cause it to act rich. If you are fouling the plug you're too rich. Go down to a 180, run 91, and start over. Why do you need to change your pilot? Unscrew the mixture screw to whatever you need it, it doesn't look like you are modded enough to worry about a pilot yet. I think:rolleyes:

[TrxTex]

I ran a mix of 108 and 91 in my high compression 400ex because of pinging. I just kept that up for no reason but that I had some on hand. I have been doing it on and off for a while. It makes complete sense now...the place where I buy the race fuel will only sell it in 5 gallons now. So...instead of a mix....Im running full 108 until I get the gas can used up a little. Enough of that though. Im going to drain it and put my 180 in and start from there with straight 91. I appreciate the help.

When I put the hotcam stage II in....will the jetting need to be changed? Should I wait until then to dial it in?

[DirtDevilBT]

Originally posted by TrxTex
I ran a mix of 108 and 91 in my high compression 400ex because of pinging. I just kept that up for no reason but that I had some on hand. I have been doing it on and off for a while. It makes complete sense now...the place where I buy the race fuel will only sell it in 5 gallons now. So...instead of a mix....Im running full 108 until I get the gas can used up a little. Enough of that though. Im going to drain it and put my 180 in and start from there with straight 91. I appreciate the help.

When I put the hotcam stage II in....will the jetting need to be changed? Should I wait until then to dial it in?

Is that the mid/high rpm cam? You may need to change your main but other than that I am looking for the same information.

[TrxTex]

Yep....its the mid to top end although their dyno shows gains all the way up.

Check it out....Hotcams Stage II (http://www.hotcamsinc.com/images/dynocharts/1024-2.jpg)

[joe1l]

The reason you are lean, is that you have not moved your needle position, you need to move the clip down in order to richen up the midrange, you'll see your plug darken up afterwards!

[fab410]

I put a hot cam stage 2 180 main and i size bigger than stock pilot HMF full system and a power now valve and im having the same problem i thought i was hitting the rev but i knew something wasnt right i only rode it 15 min before i had to go to watch the superbowl ill fine tune it this weeked so if you get your setting right let me know what they are