Engine Revving

[gunslinger]

Just got an '02 blaster on trade. Runs well, but will not idle at start up. Simple carb adjustment, I am sure. The feller I got it from told me that he just had new reed valves installed and the carb rebuilt. What I am worried about is when the engine is warm and I either have it in neutral or clutch in, the quad will rev so high, like it is going to blow. At this point, the kill switches will not shut it off, and the only way to get it to calm back down is to stick it in gear and let the clutch out. The guy was running straight mixed gas through it with an empty oil tank. I thought maybe the carb was sucking straight air in through the injector hose, but when i blocked it off, the problem persisted. Does anyone have any idea what might be going on? Like I said under normal load, all seems well.

I am new to this forum, and appreciate any knowledge you can impart on me.

Thanks so much in advance.

 

[GraffitiDan]

I have this problem too ... cold start it will run for maybe 30 seconds at fairly high rpms and then slowly just die (unless I give it gas). But after riding it, it seems to idle ok. Did you figure out what the solution is?

 

[dharbeck]

adjust the carb. that is your problem. Start at the stock setting (listed in the blaster service manual in the DIY section). If you give the 4 wheeler gas when it revs like that is will kill the motor too because the mixture will become too rich. Remember to adjust the mixture on the carb to stock settting and the mixture on the TORS/air screw if your blaster still has it. Start with the stock setting on the carb and then you should just be able to move the TORS/airscrew under the seat to set your idle (if it is all stock). If that does not work start working on the carb mixture screw in very small increments.

The only other thing it could be is an airleak but I would place my bets on a carb adjustment.

 

[GraffitiDan]

adjust the carb. that is your problem. Start at the stock setting (listed in the blaster service manual in the DIY section).

is the adjustment you're talking about the 'pilot air screw' ... it was a little off stock (1 1/2 turns out) if so.

what other adjustments do i need to make? i'm looking it up in the service manual now, but i had mixed luck on clutch adjustment earlier this week.

 

[jeepinncreepin]

idle screw under the seat flathead to turn it

 

[GraffitiDan]

Awesome, I'm in business. Here's what I did:

1) ensured my air screw was 1 1/2 turns out from fully closed
2) turned my tors screw (under seat) all the way counter clockwise (lowest rev)
3) repeatedly tried to start it, then increased tors rev, with limited success of it running for several seconds then dieing
4) eventually my tors was all the way turned clockwise (highest rev) ... but it wouldn't stay running
5) it stopped even attempting to run
6) !!! FILLED WITH FRESH GAS / OIL MIX !!!
7) adjusted tors back to mid-screw
8) started and ran great, a little high on revs
9) adjusted tors counter clockwise in 1/2 turn increments until it ran normally
10) rode the sh*t out of it in my yard!!

So I think the root of the problem was old or incorrect mix gas. When I got it a couple of weeks ago the guy said he mixed at 40:1 and who knows how old the gas was. But I'm sure adjusting the air and idle helped.

I'm super pumped to get on the trails next weekend now.


ps. also after letting it idle for 5 minutes or so, I shut it down and checked the new spark plug I put in last week ... it looks perfectly tan.

 

[06blasterboy06]

hey i have the same problem how many gallons of gas to a once of two stroke oil and i got a new air srew ajusted the tors and still rev med its was high now med rev thanks every one