Has anyone had this carb. gum problem?

6 replies to this topic
  • thmpr77

Posted April 22, 2004 - 02:58 AM


I've got an 02 YZ426. I run Turbo Blue race gas and I use the No Toil air filter cleaner & oil. I've been having a problem with the carb. getting this sticky blue gum buildup on it. I tried lightly oiling the air filter and it helped but eventually the gum appears. I talked with the owner of No Toil and he had never heard of the problem. The oil is red and the gas is blue, so I'm thinking there may be a reaction between the two that's causing this blueish gum that gets everywhere inside the carb and causing the bike to run like crap. I'm not over oiling the filter, if fact, I'm probably under oiling it. I always give the oil time to evaporate before starting the engine. My buddy uses the same gas with a different filter cleaner with no problems. I'm just wondering is there anyone else using this combination and having any problems.

  • TonyDeCoster

Posted April 22, 2004 - 03:51 AM


That's race gas for you...I use U4 and found that the carb will gum up much sooner than with pump gas. There seems to be a lot more evaporation going on with the U4 judging from the amount of fumes in my garage. I have to plug the vent hose and drain the carb to prevent getting gassed out of my house...

  • Wyatt

Posted April 22, 2004 - 10:16 AM


I get a blue-ish type of varnish down the throat of my carb (motor side) and on the slide (motor side). I always thought that it was from when the gas evaporates and left the blue dye behind. That could be totaly wrong.

It has never caused any problems for me, although I do clean my carb often as part of routine maintenance.

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  • YZ426FPilot

Posted April 22, 2004 - 02:26 PM


Wyatt is right. It is the fuel evaporating and leaving the dye behind. Try cutting your race fuel with some premium unleaded or try to buy 103+ unleaded from the pump if you can. It wont have the dye in it.

Unless you plan to tear you carb apart after every weekend, I wouldnt run the race fuel all the time. It is really hard on the rubber seals & orings. The 02 YZ426 runs too damn good on premium pump gas to go through all that trouble. :)

  • beezer

Posted April 22, 2004 - 02:38 PM


The bikes are designed to run with pump premium.

  • thmpr77

Posted April 23, 2004 - 02:38 AM


Thanks for the input. I've been running this race gas for 2 years and you can tell a huge difference with this compared to premium pump. What makes this problem puzzling is that I've got 2 buddies with 450's using the same gas that have never had a problem. I guess it could be possible that I got a batch with a higher dye content, although I doubt it?? I think I'll follow the advice and try cutting the gas 50/50 and see what that does.

  • aford541

Posted April 24, 2004 - 04:35 PM


I run 1 gallon of race gas to 4 gallons pump just to stabilize the octane, my bike runs more consistent now than it did on straight pump gas. Honda ran a 95 octane in their race 4 strokes last year and that is what it averages out for my mix and I don't get any of the gum stuff like I have in the past with straight race fuel.

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