Sick 1996 Polaris SLX

[xpwarrior]

My friends SLX will run great for about 5 minutes then all of a sudden it won't rev past 3500 rpm. The engine is not missing, stumbling or hesitating it just won't go any faster. Giving the choke a quick pull doesn't help either. I think it acts like the rev limiter is kicking in but the gauge is not showing overheat or low fuel/oil. Since the gauge is a little screwy anyway we tried disconnecting it and the overheat sensor with no luck. Most likely the CDI box is getting warmed up after running a few minutes then causing the problem right?

Thanks
Jason

[Bryan Glynn]

I would check the plugs first. What are you using and what is the gap? Install a fresh set and try again.

[SeaLion]

The ski has a limiter when you get to 1/4 tank of gas. Sometimes the gauge won't even flash red before it kicks into limp mode. Fill up the tank and you will see that it should be fine. I put a switch on mine that I can turn the gas gauge off and it will bypass this low fuel rpm limit feature. The other thing might be the LR-54 relay that actually triggers the limp mode but I have never heard of one going bad. In the electric box, it is the part that has pink (fuel), tan (overheat) and gray (grounds cdi) wires going to it.

[xpwarrior]

Tried new plugs. BR7ES at around 030. Didn't change it. The weird thing is that it is not missing at all. The engine runs exactly like it would at half throttle but when you pull the throttle wide open nothing changes.

I thought they had a low fuel/oil/overheat limp in mode. That was what I was meaning by rev limiter. We filled the tank and it reads full on the gauge with no luck. Even went as far as pulling the fuse for the gauge and the overheat wire. I didn't know about the relay doing that so i'll check it. Thanks

[SeaLion]

The ski takes BPR8ES with .028" gap. The "P"rojection tip plug is important to use on the Fuji engine. Although I doubt this is your problem, I would put the correct plugs in it anyway.

[rexsltx]

Had similar problem with a 98 sltx,the problem was the start stop switch.After replacing the boat runs fine.

[Wet Wolf]

Get inside the elec box, and disconnect the gray wire going to the CDI, this will eliminate the revlimiter. If it still goes into misfire after 5 minutes, you will have to get it hot to the point of failure, then check the coils with an ohmmeter. You might have an ign coil, or stator coil breaking down.

Bruce Wolford
Wet Wolf Tech http://www.wetwolf.com

[Skexies]

This is very interesting.

My fuel gauge has never worked, but it has never flashed the "warning" light either.

I did get the "low oil" light and warning though, so that works. My ski also peaks 6400 in the flat water and seems to hit the rev limit at 6700 / 6900? when in chop.

What is the rev limit with low fuel? Wonder why I don't see it?

-Skexies

[SeaLion]

The SL750 didn't have the low fuel rev limit (limp mode) feature. 95 and newer 780's had it. You are lucky you don't have one because I don't know a single person that likes it. I put a switch on mine to be able to turn off the gas gauge when the low fuel limiter kicks in. This fools the limiter and I can go past 4200rpm.

[Skexies]

Heh, ok. Glad I don't have it... It does sound like a lame feature.

[SeaLion]

Polaris used it because they didn't have a reserve setting on the petcock. It was their way of letting you know that you are getting low on gas and need to fill up. I bet their logic for doing this was to not run out of gas at full throttle and risk a seizure.