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Discussion Starter · #1 ·
Hi everyone - just hoping to get a little advice. I now have about 350 miles on my 2000 SXR 700. The sled runs well - except the following:

1) On cold start can't choke for long - will bog and backfire when you take off if you do.

2) Must get up to speed (6000+ RPMS) as quickly as possible when cold to prevent bog (sounds like it runs on 2) - Then it runs and idles fine

3) After hard run (ie lake) it will not maintain 5000 - 6000 RPMs - it bogs like mad

4) After hard run will not start without input from throttle


Does this sound like it is running rich or should I be looking at something else?

Thanks in advance!!!
 

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when it bogs, have you tried hitting the choke? If so, did it die? Cuz it could either be flooding or be starved.
 

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I ride with two guys that have yammi's, what your descibing happens to them too! Only when we trailer, if they leave them in the garage and pull them out for a ride.......nothing. They both also go through a bunch of plugs, from cold starting and fouling.
 

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When you trailer do you shut the gas off? Cuz if you don't, it might be flooding.
 

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Discussion Starter · #5 ·
I don't trailer so no I don't shut the gas off.

Also the one thing I do know for sure is if I choke when it bogs - it's all over...

I lost two plugs my second time out - switched to Amsoil - haven't fouled another one. Actually they look as if they're burning well (porcelin is tan).

Any more ideas?
 

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Sounds to me like one of two possibilities.

1. Your needle n seats are leaking and are letting in too much fuel into your carb and then into the combustion chamber. Replace them.

2. Your choke cables need to be adjusted. They may actually be open even when the choke lever is off. This will again dump in too much fuel which will produce the bog and fouling you describe. Adjust the choke cables to spec.

I'd start with these two things as they are cheap and easy to do. Let us know what you find.
 

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Discussion Starter · #8 ·
Thanks - I'll check the choke cable first thing this weekend. I'm not even sure how to check the carb synch - though that makes sense as well.
 

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You want the slides in the carbs to open and close at the same time. You also want the idle screw on each carb to be the same. These are what control the idle by holding the slides slightly open.

Do a search in the shop section for carb sycronization or carb related. There is a lot of info here on it utilizing the drill bit method.
 

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Yamaha uses a carb rack so the carbs once set never need syncronization. Also there is no place to shut the fuel off. It is pumped over the air box mount. I would try dropping the needle a notch.
 

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Discussion Starter · #11 ·
Ok - I think the firs thing I'll do is check the choke cable. After that it is after the high-speed jets.

Is it one jet or three? Also - is it hard to get to / when I get it out will I know what size it is currently so I know what to order?
 
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