JETTING PROBLEMS?

[inacoma91]

After reading when you run race fuel or av gas it burns clean and white i went and checked my plug. Well I do run some race gas that i have left over from the weekends from my race car. I run about 40/60. I see that my electrode is nice and brown but on the edge of the plug right above the threads to screw in the plug it is white on that space. So it must be burning clean then???? Least i am not the only one getting the white................

[skemp]

Well guys, I got some pump 92, drained the Av. gas out, and ran it for an hour, then went wide open, checked the plug, and it was still white. This seems weird, because before I added the pipe, my plug was always nice and brown after dialing it in for the air filter and airbox lid modification.

Oh well. I have a 172 in there now (I think )

I even tried an older plug, and it turned from dark brown to light gray. I think it is fine now, it runs good, and anything above the 172 was too rich.

I will try ogre's method too see how that works out. I feel better about the plug being white now. You guys have been a great help, thanks!

[Guy400]

skemp, are your intake boots tight around the carb and at the head? There shouldn't be any reason why you're still burning white. If I were you I'd have the bike sniffed that way you know for sure what your air/fuel mix is. Something just isn't right...

[4punksdad]

I am up to a 165 and mine is still burning white & it still runs fine........no real power increase or decrease.........plug is white with some carbon on the threads.

[skemp]

Guy, I think maybe my boss was pulling my leg when I asked him about the gas. Right on the pump it says "With Super XHP Additive to keep engines running longer and increase spark plug life" I think that explains it right there. Actually, the plug is getting some brown color to it, so I think it was just the gas, and I needed to run all the Av. gas that was left in the tank out.
I will definetely keep you posted on how everything is going however, and I called around to see which auto shops do a sniffer test, and found two nearby, so I can always go there if all else fails. Again, thanks for the help you have given me thus far. I will be back when I need more, or just to tell you how this is working out. Like I said, it feels strong, like I can tell a difference when I ride it after getting the jetting correct. I think I might have it right this time.

i ran 110 octane from a store near silver lake and i noticed the end of my stock pipe had a light grey and with carbon powder on it ...i think it was from thelead in the fuel

[MARCUMS ATV]

I think some of your problem is with the av gas. It has special driers in for the the air planes and will naturally give you a whiter looking plug. Try some regular 93 and see what you get. Also check your carb intake boot where it bolts onto the head. I have replaced several of these because the get a stress crack on them and your bike will suck air and run lean. The always crack at the bottom and you should be able to see some fuel leakage there. I have replaced about 60 of these in the last few months, including the one on my 400 two times.

Terry

[skemp]

All is well with my problem. I am happy with the setup I have right now. I have the Dynojet tapered needle on the 3rs groove, a Keihin 172 main jet, and soon to have a 40 pilot to remedy the idle-1/4 throttle hesitation I get. It runs great in all other aspects; no popping on deceleration, skipping on acceleration, or the like. The plug finally has color, and it is the most beautiful tan color I have seen.
You guys were helpful, informative, and never underestimated me. I appreciate that. Now that Leo put this in the "Best Of" forum, others can use it if they experience unusual jetting problems like I have. I feel so much more confident in myself after the suggestions you gave me. I'll see ya on the board!

[400exRacerX]

great thread, good info!!

[papaw]

you might want to check tihs out!!!pull the vent hose that goes from between the intake and the carb and over the carb to the heat shield. pull it out start it up let it idle and put a finger over it.if you feel a vaccum, if you do you've got a problem..don't know the fix just yet but hopefully soon enough.any suggestions on this problem would be greatly appreciated!maybe something to do with the air cutoff valve.i don't know?