Once reved, revs dont come back down- someone please help

[noid]

I need some help guys. I have a blaster that my GF of 3 years rides. The atv idles fine, but when you rev it, the revs dont come back down, the engine keeps rotating at that faster pace. If you either

1. pull the choke
2. put it in gear and roll while depressing the clutch slightly
or
3.shift up a gear

It will come back down to normal.

Is this a vacuum leak or something?

I want to try everything before i go out and spend the money on a 2 stroke leak down tester. Anyone have any suggestions?

It is happening regardless of tempurature, it was happening in the summer (75f+) and is happening still at 30f.

 

[JonS]

sounds like an air leak to me.

 

[noid]

Assuming it is an airleak, what are the remedies to make this problem stop happening?

I should note also that, even though a compression test does not measure the same thing as a leakdown tester, the compression seems fine.

 

[BlastrMastr240]

Try adjusting your main jet, i know mine (depending on temperature) will need adjusting, (most of the time to lean it out) otherwise it will rev and very slowly drop, that will also happen when your thumb throttle does not move back entirely to idle position, I might even need a new spring in mine. Make SURE to check your throttle cable as my uncle rode my blaster once, and the trottle cable was not sitting on the nut on top of the carb and the idle only went down if he pulled the choke. (make sure its snug).

 

[JonS]

well, since you mention leakdown testers i assume you know how to use one. you will need to perform the test and then check for leaks at the usual places. gaskets, case halves, reeds, etc.

find them from that and the do proper maintenance.

 

[noid]

Try adjusting your main jet, i know mine (depending on temperature) will need adjusting, (most of the time to lean it out) otherwise it will rev and very slowly drop, that will also happen when your thumb throttle does not move back entirely to idle position, I might even need a new spring in mine. Make SURE to check your throttle cable as my uncle rode my blaster once, and the trottle cable was not sitting on the nut on top of the carb and the idle only went down if he pulled the choke. (make sure its snug).

This seems to be happening irregardless of temperature.

As far as the throttle cable, it seems to be ok. For mine if you pull the choke it will go back down to normal, and then you can push the choke back in (off) and it will stay fine, until you rev it, and again wont go back down.

 

[BlastrMastr240]

When i encounter the problem you have been faced with (providing the choke example) i lean the carb main jet a turn or so, depending on mods and adain temperature. Here in michigan it WAS a beautiful 25 degrees where i go snow riding and it took me and a buddy about half an hour to find the hot spot for the jets, even more so when i put a 28mm carb on B) lol. here is another simple idea, crack open the throttle assembly on the handlebars and look to see if the thumb throttle is going back ALL the way to idle, i have yet to fix mine (i can be lazy). You can simply start the machine with the trottle lid off, rev it and push the lever all the way to the wall of the throttle case. if it dropps to idle, fix the mechanism. If not we continue searching, and never remove an air leak from the list of suggestions. I:I

 

[EvilElvis]

You are pulling in air......you need to find out from where....leak down test... or fry ur topend...Also if your carb is stock make sure the THE OIL INJECTION NIPPLE ON THE CARB IS PLUGGED OFF if not you will be sucking major AIR...

 

[EvilElvis]

Also, is it smoking major like pure white greyish smoke?

 

[noid]

Its blowing whiteish smoke, moreso on start up, tends to thin out some once warmed up.

I also smell gasoline in the bottom end oil.

Carb is stock (tors unit still attached at the top of carb, but electronically disconnected) has a block off kit, i bought it as such, where is said nipple i should check?

 

[EvilElvis]

sounds like crank seals ....but dont guess...do a leak down test....sounds like your bringing tranny fluid in ur crankshaft

 

[slickerthanyou]

I also smell gasoline in the bottom end oil.

As stated do a leakdown test! first!

Ther is a detailed instruction in here- I sell them-
http://www.blasterforum.com/engine-parts-151/leak-down-tester-43284/

A vid-
http://www.blasterforum.com/do-yourself-20/how-perform-leak-down-test-44653/

Or you can make your own-
http://www.blasterforum.com/do-yourself-20/how-perform-leak-down-test-44653/

 

[noid]

I am going to make my own. Do I do the test with the reeds in place?

 

[slickerthanyou]

I am going to make my own. Do I do the test with the reeds in place?

Yes just remove the carb block the exhuast port- leave everything else!

 

[noid]

Sent you a PM slick, would like to get a pricing on the ones you are selling.

 

[slickerthanyou]

Pm returned! !

 

[michaelbell85]

check the reed gaskets as well usually those will go at least on my 2 strokes they do