Hello. First I want to say that I came from a long line of ski doo snowmobiles. So I'm pretty familiar with them. Now my sister purchased a 2011 800 sba that had the clutch side piston completely exploded on the top. She bought a fix kit for it with longer dual ring pistons and the head spacer. I have the engine all put back together and installed in the sled. 3 pulls and it fires right up. Seems to idle a bit rough. It'll warmup then when it settles down it keeps jumping from 1750 rpm to 1950 rpm and in between. Sorry I should of mentioned it already it's a fuel injected model. Now the real trouble I'm having is the first time I touch the flipper it goes fine but after that it's like it's running on one cylinder. Release the throttle and goes right back to running good. I've hit it hard a couple times to try and get it going but I get the bog and have to let go of the throttle. Changed the plugs tonight but it never helped the situation at all. The old ones I took out were a very nice chocolate colour. Sorry if this is long and I'm leaving something out. Like I said at first I'm a ski doo guy working on a Polaris that's fuel injected so I'm in need of a bit of guidance.
2011 800 sba bog as soon as throttle is pressed
- Thread starter boostjunkie
- Start date
I was thinking along those lines. Maybe the throttle position sensor. Its definitely has to be a problem with fuel. Whether it's electronic which is something I know very little about on these sleds, or maybe an air leak which I'm really hoping it's not. Thanks for the suggestion. I will dig into it a bit more. I should also ad that someone else took everything apart and never had the knowledge and was to lazy to put it back together. Every engine I've handled from a ski doo I've leak tested. I want to do that with this engine now. On the doo you have to cap off some vacuum nipples. Are there any on these engines to cap?
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Check the throttle safety switch as suggested. There must be some free play in the cable when it is at idle or it will cause this type of condition. Easy to check and adjust. There is an adjuster right up near the throttle block on the cable usually zip tied to the bars. The adjuster is under a rubber boot which needs to be pulled back first. Loosen the plastic lock nut and turn the adjuster in until you get a bunch of free play in the cable then back it up until you have around 1/16"-1/8" of free play, then test. It will take 5 mins and will confirm if this is this issue.
Do not try and adjust cable free play with the adjuster down at the throttle body. That adjustment MUST be set only in conjunction with the TPS using a proper tester, it is not an idle screw similar to a carbed sled.
Do not try and adjust cable free play with the adjuster down at the throttle body. That adjustment MUST be set only in conjunction with the TPS using a proper tester, it is not an idle screw similar to a carbed sled.
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Now that you say this, it very well could be my problem. As I said I never took the sled apart just inherited a mess to put back together. I installed the throttle cable on the throttle bodies where I figured it should be set. Very little slack. I'll see if I can find the procedure to set both the cable and the tps. Also I'll check out the cable up by the throttle block as well. Thanks
I adjusted the tps and idle screw. No change in the situation. I'm wondering if I have a bad tps.
Throttle safety switch is most likely the problem
One thing to add if I pump the throttle really fast I can manage to get it to take it on top end and seems to work good there. I haven't tried it a whole lot this way as there's no snow here yet so I only have a distance of about 30 feet and I have to let up on it
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