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Discussion Starter #1
Hi, I bought my sled last spring, and it had this issue then. It's a 89 Yamaha Exciter 570, all stock. When the it's on a friction surface, crossing a street, or going thru powder, or starting on a hill. It will bog down and I won't be able to get going. This is followed by black smoke out the exhaust. A tell tale for a rich condition. This also gets worse as it warms up. The plugs are dark, but don't actually foul. Once the sled is up to speed it goes fine. What has me at a loss is that this sled is all stock, so I don't think I should have to adjust the jetting to get it running right. What else should I be checking???
Thanks for any help, this is my first sled, and first 2 stroke experience, but have a fair amount of experience with 4 stroke motorcycle engines. If that helps at all.

Luke
 

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Sounds to me like you need to adjust the float, sounds like it's just dumping too much gas into it......allthough I would try to adjust the air/fuel mixture on the carb/s....even though it's "stock" there's no tellin who might have tried to "tweak" it. ya never know what you got unless you've owned it from day one.
 

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what size plug you runnig in there?
If you are running BR9ES, try bringing up a heat range to BR8ES.
that'll help your burn on your fuel, and cut some of the excess smoke and bog.
your looking for a brown plug.
and as always use a good synthetic oil, Like KLOTZ, not the cheap stuff.

try these and see if they make a differance.
 

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Luke,

What have you done to the sled to get it tuned up for the season? I know that my sled runs poor with the gas stabilizer I put in it at the end of the year until I get a fresh tank of high test through it. If you haven't already I'd do the following: replace the plugs, gas and oil and clean the carbs. Make sure the air box is flowing well- pretty much the same things we do with our GS's in the spring. I have found the biggest difference to get used too engine-wise for 2-strokes is the intake and exhaust valve system. A lot simpler than overhead cams but tricky to understand how the reed valves work. These may need cleaning or replacement if they are gummed up. Intakes can get gummed up from bad gas, exhaust valves can get fouled with oil. Check them when you have the carbs off.
 

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Discussion Starter #5
Yeah, I haven't done much, I think I'll just bite the bullet and take the carbs off and clean them up, and check everything else while I'm at it. The carbs look like a real PIA to take off, and put back on, hopefully it's not that bad. Thanks for the help and I'll keep you posted.
 

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Can't be any worse than the GS!

Just a warning to a new snowmobiler- I don't know if you've ever heard this, but they say helicopters require 3 hours of maintainence for every hour of flight time. Snowmobiles are about the same. That's why you see so many guys getting a new sled every year. Welcome to the wonderfull world of snowmobiles!
 

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Discussion Starter #7
Yeah, I've heard that. As for the carbs on a GS, I can take them off rejet them and put them back on in under 20 minutes. Probably blindfolded. That's what a pipe and K&N pods will do for you, jetting headaches. Hopefully the sled will be as easy to master.
 

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Ohh, you're lucky to have those pod filters. I'm doing that next year. Hope you get your sled squared away!
 

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Discussion Starter #9
Well I took the carbs off tonight, found the needle in number 2 was bent. :eek: Where would the reed valves be? Do I even have them? I'm still trying to get into the airbox, huge PITA. That is one of the primary reasons I went with pod filters on my bike, they just simplify maintance. Anyway, the carbs looked good other then the bent needle, all set to stock settings, I'll put them back on and sync them in the next couple days, hopefully it will solve my problems.
 

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HEY FENDRGUY ARE YOU YOU GETTING A COMMISION FROM KLOTZ? YOU SEEM TO BE THEIR SPOKES PERSON, I CAN'T SEE YOU YOU DOIN' FOR FREE:D LOL
 

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klotz is great, i wont switch, its expensive but definetely worth it!
 

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You said it MAV.:D

Just a habit, ppl at the shop ask me all the time.
Its just about smokless.
leaves no residue, (SLUGE)
does'nt foul plugs
and where else can ya get oil that smells like bubblegum.

I usta be a die hard GOLDEN SPECTRO user.
Used it for all the racing years for motos and wheelers, never failed me.
Just could'nt get away from the exhaust sluge.
 

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Well I took the carbs off tonight, found the needle in number 2 was bent. Where would the reed valves be? Do I even have them? I'm still trying to get into the airbox, huge PITA. That is one of the primary reasons I went with pod filters on my bike, they just simplify maintance. Anyway, the carbs looked good other then the bent needle, all set to stock settings, I'll put them back on and sync them in the next couple days, hopefully it will solve my problems.
Well, I guess I'm not sure, but I think all 2 stroke motors use reed valves for the intake and exhaust. Here is a website that has the 1990 version of your sled on microfiche (kinda like Bike Bandit), not sure how much difference the 89 to 90 had:

http://216.37.204.202/yamaha_oem/YamahaSnow.asp?Type=12&A=5
 

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Discussion Starter #14
Well I have it all back together, but need to ride it tonight to check it out, hopefully the rain we got hasn't killed the snow on all the trails. I looked through the microfiche and can't find a reeds, and when I took the carbs off I could reach down the intake, and didn't feel anything in there. I'm pretty sure that's where it would be if it had one?
 

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Yeah, that's where they would be! When I take my carbs off, the intake valves are right between the carbs and the engine cylinders. The exhaust valves are located right on top of where the pipes attach to the cylinders. Anyone else have some input here? I thought all 2 strokes used reed valves?
 

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No, not all 2 strokes use / need reeds.
they only really started using them in the 80's, mostly motocross bikes. sleds in the mid 80's but not till the 90's that all sleds adapted to it.
example,
my 89 Indy 650 does'nt have any, but the 93 XLT's do.

If you took off the carbs and there wasnt a plate with a V shape contour between the carbs and the jugs then no you dont have any.

hope that helps.

:D
 

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klotz is great, i wont switch, its expensive but definetely worth it!
Smokeless oil scares me. I like to see a little smoke to make sure the oil injectors are doing thier job! Of course the bubblegum smell would be nice...
 

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Fisrt Question When did you buy this sled because if u did buy it last year i may have rode it is it red in color and did u buy it off a guy named cj and traded a boat for it if yes please let me no with a yes or no im his kid i was there when you bought maybe so if this is you even if your not the person i think you just please reply back is all i ask i know the problem just have to go and to much to type Thanks Tyler
 
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