Still not hitting top end

[drolds]

My 96 sl 780 was running perfect when I winterized it last year, after putting in a new pump stator and impeller. This spring, it started right up but was in limp mode. Did a search here, found the common float problem, and fixed it. Gauge now works, out of limp mode, but it tops out at about 5600 rpm or so. I checked the obvious: new plugs(old ones were toasty brown), good spark, no obstructions in pump. Was there something else I was suppose to do during the float repair that is causing this? I am 95% sure I reattached fuel lines exactly as they came off, but would the ski run at all, if I accidentally swapped 2? Application of choke at any rpm immediately kills it, so I don't think I have a lean condition. Any ideas?

[xlint89]

What impeller did you install?

[drolds]

It was a Skat trak 13/18. Old one was heavily damaged. Actually, I think you helped walk me thru the replacement last fall! After I put it on, I remember getting 51 mph out of the MFD. Not even close now.

[xlint89]

OK, that eliminates it.

Fuel pump hoses to carbs shouldn't matter if they were crossed.

Did you use Stabil in the gas for storage? Maybe it's just poor gas (old)

Maybe the carbs need cleaned if you didn't use stabil.

Have you done a compression test?

[drolds]

Yes, I even popped for the Polaris fuel treatment. Fogged it as well. I have not done a compression check yet, I guess that is next. Really does run well from idle right up to 5500. If compression checks out, carb cleaning is next. Is it easier to remove all 3 carbs as a unit? I have never pulled them off this machine. Thanks again!

[xlint89]

Run the first tank of fuel out of it before you go further. It may be bad gas.

The carbs should come off as a unit. Unscrew the 6 nuts on the under side with a short 12mm wrench, disconnect linkages (oil pump too) and remove.

[xlint89]

Just humor me.

Remove the spark plugs and coupler cover. Try turning the engine over by hand.

Does it turn smoothly or does it feel like it's binding/dragging?

[drolds]

Compression 140 dead on each cylinder
can turn over by pushing thumb across coupler.
Completely drained tank, and put in fresh gas.


Only connection I am not sure of, is, at the sending unit connections, which nipple is the fuel pickup? I think I currently have it connected to the center nipple, with the vent and return to the left and right of it.

I could not find a detailed diagram or an actual picture. Factory manual was extremely vague.

[beerdart]

The fuel nipples are marked Vent,Res,Ret and Main. Ret is between the wires and going clockwise Main, Vent, and Res.

[drolds]

only 3 nipples (much like someone's avatar)- looking at other models for ideas, I am guessing the 4th one would be for a machine with reserve. This 96 780 sl only has on and off at the fuel switch.

For giggles, I pulled the middle hose and a fountain of gas shot out (machine sitting in sun-tank pressurized) I would guess this is the fuel out nipple, as I have it connected to the filter line in, then out to the switch.