[jljm37]

compression is fine, new plugs, new gas filter, ran seafoam through -

my ski will only top out at about 40 mph. sometimes i get a burst of speed which will bring me over 60 but that last only for a few minutes or seconds at the most. The ski bogs down and only will go at the lower speed, but like i said once in a while it will jump up and give me full power.. can the carbs be gummed up ? and if that was the case how would i get the burst of power once in a while ?

someone please help.. i've been going crazy trying to figure this out..

 

[Ernest T]

Many potential reasons, but since you do get an occasional surge of speed, I'd put a dirty or degraded carb as number 1 on my list (especially if the carbs have never been cleaned or rebuilt). Theses carbs need to be taken apart and cleaned occasionally, and you are overdue if it has never been done. It is amazing that a very small defect in a needle valve, etc., could restrict fuel flow and give you an occasional surge as it turns a certain way (look for rings around the needle valve taper).

Other potential power loss problems on this model could be from a failed power valve and/or damage to a cylinder (your cylinder should be good if compression is OK). If the carbs are good (you know they have been cleaned/rebuilt recently), check to be sure the power valve motor is actually running. Not unusual for a power valve to get stuck, come loose, etc.. They don't always destroy the piston/cylinder, but could cause performance problems.

Another consideration is the cat/con. If you haven't done it already, consider getting rid of it and installing the D plate. The cat/con can fail and result in power loss also.

 

[NJMD]

I had the same issue a couple years back and had the carbs cleaned for $1000. It ran great until next season (last year). I did winterize it and everything. For this reason I have not used this season. I'm getting set to try it this weekend. I talked to someone very familiar w/ 2 stroke engines (34 years expierience and he conferred w/ someone who has even more experience. They told me to try this:

Try to empty tank (could be water getting into the carbs)
Run 93 octane (said I should always run this)
Use stabil fuel system cleaner (not just the stabilizer) Said it works great. It will smoke like hell, then run awesome.
get a water/fuel seperator into the fuel line

Any thoughts from the experts on here? He said try all this... should work. The carbs shouldn't be that gummed up after 2 seasons now (probably on 10-15 hours since the rebuild). Also, much cheaper to try this, than get a $1000 rebuild again.

Any help is appreciated!