1st - It is about 10 to 35 degrees out now, my banshee starts up fine in about 4kicks with full choke. Once running it runs really bad, firing on 1 cylinder on and off. I take it down the road in 1st gear with the choke 1/2 on most of the way to my friends house about 3mins away. There I warm it up some without any choke and after it is warmed up for about 10mins it still is running pretty bad, backfiring the one cylinder, and stuff and seems like one side is fouled up, but hits the powerband fine. Then it all clears up and runs fine the whole time. BUT after running awhile it is hard to start back up, most of the time you will see me catching it in gear. It also is overheating, even in this cold weather. Mainly it is hard starting after I over heat it or come close to it. It runs fine once started though. I'm thinking it is supposed to run this way in cold weather, or I'm using the choke wrong, or my carburators need adjusting. ( but in the spring I sent it in to get the carbs cleaned and adjusted because it would never start unless you catched it in gear, now it starts kicking it till it over heats, then its trouble.)
Also I find myself fouling my plugs a decent amount of times, even in the summer. Is it running to "rich"?? Am I mixing my fuel ratio to high of oil content, around 32:1??

Thanks

 

OK let me do a mathmatical equation: cold + two stroke = no go. Well now that we all understand that let me tell you how you can fight the cold weather blues.
First off you obviously need to rejet, go two sizes up on the main jets to give your machine more feul.
Second you need to get cooler plugs put in, whats happening is your machine is'nt overheating it's the plugs that are, when they reach a certain temp they would operate right.
Third put some dry gas in your tank to prevent the gas from solidifying.
Finally turned the air/feul mixture screw 1 1/2 turns out from the closed position.
GOOD LUCK

2000 SCRAMBLER 400 2X4

SCRAMDADDY400

 

Hey scramdaddy, your equation does not hold true. Ask anyone on the planet who owns a snowmobile if it only runs when it's warm out! They are ALL two strokes. I don't think our banshee owner is warming up his machine properly. Sounds like you choke it, fire it up, and immediately drive down the road, hitting powerband occasionally, and before you get to your buddy's house you have done permanent damage to your piston/cylinder. If you don't let the engine warm up BEFORE you drive it, the piston gets hot at a much faster rate than the cylinder. This makes it expand faster than the cylinder, and this effectively scores the cylinder walls and wears out the rings. This excess friction is causing your machine to overheat. With the swollen piston stuck in the cylinder, it is much harder to start. When everything is finally warmed up properly, your worn rings and scratched cylinders are letting oil past them and fouling your plugs. Sounds to me like your top end has been abused and needs replaced.
Addict

 

Hey, last time I tried to warm it up in the yard I had to replace both plugs because it stalled out. Also about rebuilding, I just had the topend rebuilt in july or august with wiseco pro-lites and 20over stock. Then it still wouldn't start up right, so I took it to the shop and had them mess with the carbs and they pretty much fixed it. I think maybe my waterpump impellar is melted or something like that, I am going to take a look at it over xmas vacation, because I highly doubt mine should be overheating so much. I'll try different things, such as shuting it down often if I ride in the same spot and fool around there.(that is usually the only time it overheats)

And about jetting the carbs, I bought the quad in July with all of the engine mods, silencers + K&n and I have no idea if the kid jetted it to suit these mods? Would he have to? I will check that out in the Spring when it warms up some. Hopefully I'll get this straightened out, it has been giving me trouble since the day I bought it.

 

I would say that your jetting is off.You need to see what size jets are in it now.Stock is 200 with a 25 pilot jet with the needle in the middle position,2 turns out on the air screw (2500 FEET ABOVE SEE LEVEL)Then depending on your mods go up from there.Most after market pipes start out around 260 mains.But like i said,it all depends on the bike.Usually when they are hard to start the pilot is to rich.

 

Usually if it is backfiring that would indicate a lean condition. I added a little extra oil to my gas when mixing and I let it warm up for about 5 minutes. It seems like a long time but I have not fouled any plugs and I have not had it backfire once. Plus it starts on the 2nd kick. I went riding a few weeks back, and a guy there with a Banshee had another guy pull him around the parking lot to start his Banshee. His bike was backfiring like crazy, not a good thing. Anyway good luck.

 

Addictedtomud my equation was referring to high performance two stroke ATV's, I did'nt say snowmobiles. I don't know of anybody who has a banshee and doesn't need to rejet for the winter.

2000 SCRAMBLER 400 2X4

SCRAMDADDY400

 

Hey, I have taken my carbs off and apart many of times. I have no idea how to read the size of the jets in there, I just know there are 3 in there, 1 with a **** to turn it with a wrench, 1 long skinny one, and 1 long skinny one longer than the other. I know the one with the **** in located in the bowl kind of. The others I know one is in the inlet or outlit (forget which one)

Anyways how do I find out the size of these jets? I never looked at the setting on the neddle, but I will.

And about the Pilot Jet being too rich, is this what I need to do?

Also how should I jet it for colder weather, because someone stated, they never heard of someone with a banshee not rejetting for the winter.

Thanks for all your help and anymore you can give me!

 

Hey Twinshot, increasing the oil actually leans out the mixture. Less fuel is available for a given amount of premix.

 

I didn't need any rejetting!! well...I didn't do it (yet?). It still runs great, as usual (that means faster than a 400 scrambler ). I start it with full choke (starts right on the first kick). When it's started I shut the choke off, otherwise it will stall and then will be a pain to restart (like 10-15 kicks...dunno why), then i start riding. Right at the beginning, it runs bad, the clutch isn't very efficient...all the normal stuff. After 1 min it runs fine (both cylindrs, clutch works) but can't reach the powerband. After I don't know how much time, it's hot and can go WHAAAAAAAAAAAM all around the trails. When it's hot, it fires at first kick (unless it's been sitting in water up to the cyl -the low part of the cylinder-).

Check your carbs, something's wrong there.