Sputters At High RPM

[Ryan]

I recently toke my quad out for a ride and noticed when I try to REV it up, it sputters slightly. I replaced the spark plug and that wasn't the problem. As far as I know, my air filter is clean, (cleaned recently).

Im guessing since the temperature have dropped, I could be running to lean. Possibly I might have to up the main jet.

I was also thinking since I am having trouble keeping my air boot clamped on to my carburator, this could be letting some unwanted air in.


I have not tried plug chopping yet, but I might have to so I know if my main jet is running lean.



Anyone else wanna shed some light on the subjet?

Thanks in advance :cool: .

[AndrewRRR]

Yes, do a plug check. To check if you have an air leak around the carb boot spray some WD-40 or starting fluid around the area. If the rpm goes up you have a leak.

[cals400ex]

is it studdering at full thorttle or just at higher rpm's when cruising? what size main are you using? an air leak could be causing problems if you have one.

Originally posted by Ryan
I recently toke my quad out for a ride and noticed when I try to REV it up, it sputters slightly. I replaced the spark plug and that wasn't the problem. As far as I know, my air filter is clean, (cleaned recently).

Im guessing since the temperature have dropped, I could be running to lean. Possibly I might have to up the main jet.

I was also thinking since I am having trouble keeping my air boot clamped on to my carburator, this could be letting some unwanted air in.


I have not tried plug chopping yet, but I might have to so I know if my main jet is running lean.



Anyone else wanna shed some light on the subjet?

Thanks in advance :cool: .

it is either ur jetting or ur rev box

[hondarider2006]

how long do rev boxes go out? Or do they usualy never go out?

Originally posted by hondarider2006
how long do rev boxes go out? Or do they usualy never go out?

i think the stocker is like 8500 or 9000rpm

[hondarider2006]

Originally posted by XxHonda_RacerxX
i think the stocker is like 8500 or 9000rpm

I mean how long do they last before crapping out?;)

Originally posted by hondarider2006
I mean how long do they last before crapping out?;)

pretty long time...if u got the aftermarket carb then it lasts not that long...but if u got the stock carb then its fine...i never hit the limiter when i had the stock stuff...but i only hit it once since then so it should be pretty hard to get up to that high an rpm

[2004TRX450R]

Is your choke off? Also check your air box and make sure there wasn't a mouse that got in there and built a nest if the bike has been sitting for very long. Most likely just needing a jetting change due to conditions change.

[hondarider2006]

Originally posted by XxHonda_RacerxX
pretty long time...if u got the aftermarket carb then it lasts not that long...but if u got the stock carb then its fine...i never hit the limiter when i had the stock stuff...but i only hit it once since then so it should be pretty hard to get up to that high an rpm


on snow/ice its very easy to hit;)

[AtvMxRider]

Originally posted by XxHonda_RacerxX
it is either ur jetting or ur rev box


This is on a blaster.

[UglyMotha™]

Originally posted by XxHonda_RacerxX
pretty long time...if u got the aftermarket carb then it lasts not that long...but if u got the stock carb then its fine...i never hit the limiter when i had the stock stuff...but i only hit it once since then so it should be pretty hard to get up to that high an rpm



dude he's not talking about the hitting the rev limiter he's talking about how long before they go BAD


it's pretty rare for them to go bad unless it's a aftermarket the stock one's will normally last the life of the bike, but they do somtimes go bad, but i don't think that's your problem

[BBW]

If it runs good under all conditions except high rpm's I would highly recommend at least looking at the rev limiter. As far as how long they last your guess is as good as anyones. A couple months ago a friend of mine had the same problem your describing. We tried everything and couldn't find the problem. He rode it the rest of the week-end with it cutting out at high rpm's. When he took it in they immediately replaced the rev limiter which ended the problem. Makes a guy wonder just how often they do go out. Keep us posted.

Originally posted by UglyMotha™
dude he's not talking about the hitting the rev limiter he's talking about how long before they go BAD


it's pretty rare for them to go bad unless it's a aftermarket the stock one's will normally last the life of the bike, but they do somtimes go bad, but i don't think that's your problem

OOOOOO...its also a blaster...so i have no clue why i am in this thread now...i thought it was about a 400

[Ryan]

Sorry, I forgot to mention this was a Blaster.


I have not plug chopped or checked for any air leaks yet...... Its to damn cold outside! :o

The quad seems to sputter when im trying to rev it out. Even at 3/4 throttle, it cuts out a little bit.

As soon as I get a chance this weekend to check the jetting, and to see if there is an air leak, I will post the results.


Thanks.

[cals400ex]

is it not revving past 1/4 throttle or so??
i think my friend runs a 270 mainjet with full pipes and a K&N filter.

[UglyMotha™]

Originally posted by cals400ex
is it not revving past 1/4 throttle or so??
i think my friend runs a 270 mainjet with full pipes and a K&N filter.


:huh

[rap169]

i am experiencing the same prob with my yz490 i just bought. im guessing its the jetting, air leak, or low compression. BUt it rens good low to mid rpm, so i duno bout the compression. then again, ive never really messed with 2 strokes before. I hope i get it figured out.

[cals400ex]

Originally posted by UglyMotha™
:huh

i think he is talking about the blaster. :confused:

[UglyMotha™]

what's this 270 mainjet in that you refer to :confused:

[cals400ex]

Originally posted by UglyMotha™
what's this 270 mainjet in that you refer to :confused:

270 main is in the blaster. i think the stock jet is 230. their jetting is different from outs since they use mikuni carbs and it is a two stroke.

[Ryan]

Well I just got done plug chopping.

My plug color (Electroids) is tan, So I guess its not my jetting?

I still have not checked for leaks in the carburator. My guess now it is either an air leak somewhere, or possibly my main jet could be slightly clogged.

[Ryan]

Problem solved! :D


I just got off the phone with my local motorcycle mechanic. He suggested something about my TPS and shoving a paper clip somewhere? So I got kinda confused on what he told me to do.

I looked at my coil, disconnected the wire comming from the back of it, then shoved a paperclip in there, and taped it up. It seems to be running like a charm now.

All I gotta do is clean up that piece and put eletrical grease in there.

[hondarider2006]

Originally posted by Ryan
Problem solved! :D


I just got off the phone with my local motorcycle mechanic. He suggested something about my TPS and shoving a paper clip somewhere? So I got kinda confused on what he told me to do.

I looked at my coil, disconnected the wire comming from the back of it, then shoved a paperclip in there, and taped it up. It seems to be running like a charm now.

All I gotta do is clean up that piece and put eletrical grease in there.

glad to hear that its fixed;)