First ride EVER, Need help!

[douglee25]

So this past winter, I rebuilt a '93 sl750. I rebuilt the entire motor myself. It's bored 0.020" over now, boyesen reeds, triple outlet fuel pump, rebuilt carbs, etc. I ran it on the hose (as some remember my question about the rev limiter) before I put it in the water. On Mother's Day I took it out on the Delaware with my girlfriend. The ski started right up and I ran through the no wake zone for about 5 minutes to insure it was warmed up. I finally got on it, and the boat came alive. I averaged about 40 mph for the entire hour we rode. I topped it out once at about 47 mph, but I didn't want to beat on it too much since I'm still breaking it in.

Story:

While idling in the water, the ski seems unstable. I'm not sure if this is because I had two people on it, but my girlfriend says the other skis she's run previously aren't "roll happy" as this one seems. What I do know is, somehow, we got off balance and the boat started to list to the left. She pushed me to the left to right herself up, and I'm sure you can guess what happened next... We went over. The water was about 40 degrees F. We rolled the ski back over and had a hell of a time boaring it with two people. Back on the trailer, I lifted the seat. Water in the hull... maybe an inch or so. Previously to pulling the seat then, we pulled it twice earlier in the water, and no water from the pump mounting area or the driveshaft, so I'm pretty sure it's safe to say it came through the seat (the front hatch tray was dry).

Questions:

1. Are the sl750's prone to rolling for some reason as compared to other skis?

2. Is it just harder to balance with two people versus one?

3. Do I buy a new seat seal and adjust the fit with a new one or if the original seal looks good, do I adjust the one on there now? The seal seems to be tight on the latch side, but I'm not sure how tight the seal is towards the front of the ski (may have to bring the front latch pegs down slightly).

Please help with the above!

All in all, I was quite impressed with the handling of the sl750. I don't have much to compare it to because this is the first ski I've ever owned/ridden. I also pulled the plugs after my ride, and they all appear to be of decent color. I still want to do the high speed kill test to verify if the motor is running lean or not on the top end. I suppose I'll save that for a warmer weekend.

Doug

[Technical Support]

Re: First ride EVER, Need help!

Welcome to PWCs!

A good rule of thumb is, for each seat a ski is rated for, subtract one for good riding. a 'two seater' is really oly good for one. a 'three seater' is really only good for two. By good, I mean easy to balance, comfortable to ride, etc.

Yes the older Polaris hulls were more tippy than most, and yes adding more weight to any ski effects the balance - smaller lighter skis such as yours even more so. You will get used to it, and it can still be very fun with 2-up, but it's different. What you are describing is perfectly normal.

[douglee25]

Re: First ride EVER, Need help!

Welcome to PWCs!

A good rule of thumb is, for each seat a ski is rated for, subtract one for good riding. a 'two seater' is really oly good for one. a 'three seater' is really only good for two. By good, I mean easy to balance, comfortable to ride, etc.

Yes the older Polaris hulls were more tippy than most, and yes adding more weight to any ski effects the balance - smaller lighter skis such as yours even more so. You will get used to it, and it can still be very fun with 2-up, but it's different. What you are describing is perfectly normal.

Interesting. I guess I just need some more seat time. Also, another note I had a question about. When I pulled the plugs, they were all a tanish color from my hour ride. Like I said I didn't do the high speed kill because I'm still breaking in the engine. What I did notice on one of the plugs were brown like specs on the top portion of the porcelain. No other plug contained this, and it did not look like dentonation (detonation is usually burnt into the porcelain). I took a rag around a screw driver, and I rubbed the spots with it. They wiped clean off (plug slightly wet from the load speed run back to the dock). I was almost thinking that I took in a mist of water when the ski was upside down. I ran the ski on the hose for a while to make sure I cooked off any moisture that ended up inside the engine.

Any idea what that could have been?

Doug

[Technical Support]

Re: First ride EVER, Need help!

Just pulling the plugs like that doesn't mean anything.

[douglee25]

Re: First ride EVER, Need help!

Just pulling the plugs like that doesn't mean anything.

How so? It may not tell you how the high speed circuit of a carb is doing, but it sure will tell you about the low to mid circuit. Technically one could have a carb dialed in for the high speed circuit (no detonation and good plug color) but the low to mid side could still be jetted or misadjusted lean and detonation could occur.

Doug

[Technical Support]

Re: First ride EVER, Need help!

You can't detonate from a lean low circuit, at low speeds. It will perform poorly though. Unless you do a controlled test, holding at a specific throttle position then cutting the ignition and pulling the plugs - it's meaning less. No matter how you test, if you change throttle position, come back to idle, shore, etc. - it's meaningless. The readings are completely off. You also can not take readings during break-in. You must wait until you are running a normal oil mixture.

[douglee25]

Re: First ride EVER, Need help!

Unless you do a controlled test, holding at a specific throttle position then cutting the ignition and pulling the plugs - it's meaning less. No matter how you test, if you change throttle position, come back to idle, shore, etc. - it's meaningless. The readings are completely off. You also can not take readings during break-in. You must wait until you are running a normal oil mixture.

Precisely. Currently I'm running 32:1 so I'm sure I could bump that up to 40:1 or more when I'm ready to do some carb tuning.

Doug

[Brian J]

Re: First ride EVER, Need help!

The first time out... everyone’s got a story, mine is similar to yours.

After you roll your ski… get it started right away and then run it hard for half hour or so.
Then Fog the engine when you get it back on the trailer then again after you flush the motor. I fog my ski after every time out.

As for the seat seal… IMO no matter how well the seat is sealed and the hatch’s you will take on water when you roll it. Best practice is to live the experience. Roll the ski at the ramp and roll it back over and see how you handle the situation and how you recover from it. Better to now how at the ramp then in the middle of the lake or ocean. See the tech articles on the subjects.

Good luck and enjoy the fresh air out on the open waters.

[Technical Support]

Re: First ride EVER, Need help!

Precisely. Currently I'm running 32:1 so I'm sure I could bump that up to 40:1 or more when I'm ready to do some carb tuning.

Doug

32:1 for the first tank only. 40:1 after that.