2 Stroke X, Running like crap

[TwoHundredEx]

Well I was supposed to go riding a couple weekends ago for the first time on it, spent all day getting it ready. Too bad it pissed rain all weekend and never had a chance to get out.
Anyways, the day that I was getting it ready, it started off running great like it was before, just a b*tch to start on the initial start up.
Took it around the backyard and down the street to open it up, made sure everything was tight and shifted fine, etc.

It was running great, lots of power, idled fine, and didn't bog.
So I let it sit for about an hour, buddy calls me and says he's on the way to pick me up.
So I go back out there one more time to warm it up and get it ready to go in the truck and it's yet again, a b*tch to start, then when it finally did, it wouldn't rev out all the way.

Everything up to full throttle was fine, but as soon as it tried to rev out, it popped and sputtered and would almost stall until I let off it. I got on it and took off and it did the same thing under a load (obviously) so I pull the clutch in, pin it and it eventually clears out somewhat. Take off again and it does it a little then clears out and runs decently, doesn't seem to have quite as much power though.

I took it out yesterday again to see if it was still doing it and it did the same thing. Spits and sputters but eventually clears out and runs OK. Only, today it went away, then came back, then went away again. But after going away for the second time it seemed to run OK again. WTF. I didn't get to ride it much longer after that though. I was trying some full load starts and popped the chain off after a few tries. I was too fed up after that to work on it anymore.

Heres the vid. This was the initial start up, and it starts sputtering about 8 seconds in, it was worse than that though, later on.
You can also hear what 300rman started a thread about a week or two ago. How it seems like it's hitting a rev limiter on the intial start up and needs to "break through" before it'll rev out.

http://media.putfile.com/April-9th-2-stroke

[super90]

First things first. Did you clean the carb? Also shouldnt 2 strokes usually run silencers?

[TwoHundredEx]

First things first. Did you clean the carb? Also shouldnt 2 strokes usually run silencers?

There is a silencer on it, it's just hard to see in the video because it's center mounted. I cleaned the carb a day before it originally started sputtering, although it could be something as simple as that, since it didn't do it right away. Wouldn't it do it throughout the entire RPM range though if that was it?
The only thing I changed with it was the gas. Honestly can't remember what it was mixed at though, because it was mixed about a week before I put it in. I beleive it was 20:1 but it might've been 32:1. If it was 20:1, could running too rich cause this?

[super90]

Running too rich could definatly cause this. If it was the jets, the main or pilot could be clogged causing it to run different in higher or lower rpms.

[Erics350x]

Could it be the float is sticking or set to high, flooding the engine after it sets? I'd go through the petcock and carb one more tim.

[TwoHundredEx]

Okay, I'll go through the carb again tomorrow if I have time.
The floats could very well be set too high, I adjusted them back when I had a manual for this thing, then lost it and I have NO idea what the stock height is.
I keep thinking 23mm, and 15mm, either of those seem like they could be possible?
Should I lower it a tad anyway?
The petcock should be clean, but I'll go through it again. I cleaned it when I painted the tank and it's barely had a tank and a half through it since then.

[300rman]

i dont think a rich oil mix will cause this. man, your boggy sputter has officially progressed, while mine hasnt changed. i am hoping a rejet will fix it.

as for the hard ass starts, it is probably due to improper pilot jet/air screw settings. also could be the reeds or a weak spark.

what color is your plug turning out to be? maybe the motor has to be jetted richer carrying a heavier load?

EDIT: looked at the vid, noticed alot of smoke when it was sputtering. maybe its too rich on the main? try revving it out while fiddling with the choke. if it getts better, even for a second, its too lean. if it gets worse, its too rich.

always remember when messing with the jetting, take a note on where its at before messing with it.

the guy at the racing shop said the best way to dial your main in is to richen it till it sputters at WOT shifting into third and fourth, then back it off one jet size till it stops sputtering again. but make sure your engine is warm when doing the sputter test. after that, if you have a problem fouling plugs and you keep it opened up alot, to back it off one more jet size. but if it fouls up with more "putt" time on it than ripping, then the midrange jets/needle need attention. he said plug chops are good, but due to variables can sometimes be misleading.

[TwoHundredEx]

i dont think a rich oil mix will cause this. man, your boggy sputter has officially progressed, while mine hasnt changed. i am hoping a rejet will fix it.

as for the hard ass starts, it is probably due to improper pilot jet/air screw settings. also could be the reeds or a weak spark.

what color is your plug turning out to be? maybe the motor has to be jetted richer carrying a heavier load?

EDIT: looked at the vid, noticed alot of smoke when it was sputtering. maybe its too rich on the main? try revving it out while fiddling with the choke. if it getts better, even for a second, its too lean. if it gets worse, its too rich.

always remember when messing with the jetting, take a note on where its at before messing with it.

the guy at the racing shop said the best way to dial your main in is to richen it till it sputters at WOT shifting into third and fourth, then back it off one jet size till it stops sputtering again. but make sure your engine is warm when doing the sputter test. after that, if you have a problem fouling plugs and you keep it opened up alot, to back it off one more jet size. but if it fouls up with more "putt" time on it than ripping, then the midrange jets/needle need attention. he said plug chops are good, but due to variables can sometimes be misleading.


Should I lean out or richen the air screw to help the starting? I assume I'd richen it because it's a lack of fuel causing that right?
Screw it in to richen, out to lean?
A weak spark was also something that crossed my mind.
When I originally first had it running after getting the motor in the trike, the plug was a nice golden brown. 2 plugs later it's black, so it's definitely running rich.
I'm going to try some fresh gas and mix it a littler leaner, clean the carb, mess with the air screw, and throw a new plug in it this weekend and see where that gets me.
The next thing on the list is new reeds also. They SEEM fine, but they should probably be changed.

[300rman]

yes, if it is an air screw, IN to richen, OUT to lean, but if fuel flows through that circuit, then its the opposite. your pilot jet will also have an impact on your starting. maybe pick up a richer pilot and try that as well. and try leaning out the main jet to see if it stops. but fiddle with the choke first, and see if it straightens out as you hold it open. if it does, main needs to go richer. if it gets worse, try leaning her out a bit. but keep an eye an her and dont fry it by going too lean.

as i said, the oil mix shouldn't impact anything too much. i run 20:1 and get good plug color.

read the jetting thread stickied up there in trikesylvania. may help you understand what the circuits do a little better.

[TwoHundredEx]

Yeah, jettng was something I was never that great on.
I can tear apart the engine and put it back together but don't ask me what RPM range the main jet affects. :lol:
Thanks for the help, I'm going to bear down and figure this thing out this weekend if I have time.
I'm sick of trying to "band aid" the problem by covering it up with something else, If ya know what I mean.

[The Goat]

i'm only gonna say this, cause i've read more than a thread or two where people have made this mistake.

more oil means less fuel...and therefore a leaner condition.

[cr480r]

its loaded up... my bike used to do the same thing... it was a combination of a seeping petcock and float... try unhooking the fuel line before letting it sit...

[300rman]

i'm only gonna say this, cause i've read more than a thread or two where people have made this mistake.

more oil means less fuel...and therefore a leaner condition.

true
but i think in order to have a serious effect, a motor would have to be jetted for a 50:1 mix, and then start dumping a 20:1.

although i believe you should find one mix ratio and stick to it.

[SYKO]

............sigh...........ever foul a plug in a 2 stroke before? put a new one in! NGKbr8es also check the inlet or above the float needle for trash there.

[The Goat]

ya got all snippy syko but he's rolly in a zuki not a 250r man! lol. he's most likely right though, the gorilla has been known to know a thing or two.

[jeffatc250r]

I would try plugs, if it still does it i would look into some sort of electrical problem, like a weak coil.

[300rman]

I would try plugs, if it still does it i would look into some sort of electrical problem, like a weak coil.

i would think a weak coil would give problems at low RPM, and go away at high rpm though?

[SYKO]

on a 2 stroke If you have any weak spark, if you can get the engine rolling hard enough it will fire enought to keep running at a higher rpm, also I fouled plug will act the same, as its harder for the spark to make its way out (more resistance at plug end)

[300rman]

well, i think our midrange bog is created by a lean mid-circuit.....

read this http://12.227.214.171/BillGivensjetting.htm I found it in another thread, and its pretty useful.

[TwoHundredEx]

well, i think our midrange bog is created by a lean mid-circuit.....

read this http://12.227.214.171/BillGivensjetting.htm I found it in another thread, and its pretty useful.

That was a good read. Not all the way through it yet, but thanks for the link.