Polaris SL 750 RPM'S

[Lenchmob]

I have a 1995 polaris sl750 with prok f/a's and a jetlyne waterbox. I am only reaching 6350 to 6360 rpms. It runs great and hits 51-52 mph which is better than stock. But I thought I should be turning more rpms than that. Any comments or information would be great. Thanx

[SeaLion]

I would not complain with those numbers [img]smile.gif[/img] A stock SL750 turns 6100-6200 at right around 50mph. What are you verifying your speeds with? Those are great numbers and you seem to have a good running SL750.

[SeaLion]

I was turning 6450 with mine but I had quite a bit more stuff on it. My top speed was 54 mph per gps and my gauge was showing 55mph. I had the occasional spikes in the peak speed hold of sometimes 60 mph but that is definitely not accurate. I also had mine set up for more bottom end and great hook up. Your stock rpm readings were in the 6100-6200 range. I think you have a really good running SL750 from what you have posted. BTW, the rev limiter is at 6700 and you don't want to be there anyway. Are you using the stock 4 blade impeller? Try to get ahold of a used Skat 13/18 swirl. If your rpms drop with it, bore your nozzle out to 87mm and you will gain acceleration and some speed. Do you have an Ocean Pro rideplate? That is the single best bang for the buck on a Polaris 2 seater hull.

[Lenchmob]

I thought that it should be hitting somewhere around 6500-6700 rpm. Before the f/a's and waterbox I could barely hit 50mph. I wish I knew what my rpms were before. What type of rpms were you turning in your SL? I am verifying my speed with my speedo which I heard is pretty accurate unlike the yamis.

[Lenchmob]

What exactly will that ocean pro ride plate do for my ski? I am pretty happy with my bottom end. I am just trying to squeeze out some more top end speed.

[SeaLion]

Your ski will carve and track better in all water conditions and it will be faster in rough water. It will get rid of porpoising although you shouldn't have much with your pump. If you ever get the 4" pump extension, it will make the ski porpoise really bad and the OP plate eliminates most of it.

[Lenchmob]

I contacted ocean pro and they said just by adding their ride plate I will gain a lil over 1 mph. Is that true? That is pretty good for $100.

[SeaLion]

1 mph is very hard to notice. I never bought my OP plate for speed gains. I bought it because the SL750 doesn't come with sponsons and the design of the plate enables your ski to carve better and in rougher water track better and it will increase your speed in the rough stuff, especially on an extended pump Polaris. Tell Ken at OP that I referred you and he'll probably cut you a good deal.

[xpwarrior]

If you really want to make the SL750 carve then get a set of sponsons for a SLX. The last set I bought were $12 each from a Polaris dealer and they made an amazing difference.

[SeaLion]

True and I did have the long Polaris sponsons on my SL750 but back in '96, Polaris had a nice insert kit that came with the sponsons and everything mounted from the outside. I have not seen that kit since and installing sponsons are much more difficult using bolts and nuts on the inside. You have to cut the foam out and twist into a pretzel to get your hands to the location [img]smile.gif[/img] When referring to the OP plate, it does noticeably improve the handling and it is a simple bolt on.

For anyone interested in the insert kit to try to track it down, I can scan and e-mail or post the paper I still have from the company that Polaris got them from. If they are still around then these inserts make sponson install a piece of cake?

[jalaycock]

just reading your message about the sponsons. I'm not sure where to buy those kits with the inserts included, but you can usually get the inserts themselves from your local body shop or body shop supply. The inserts are also used on car bodies and some of them require a tool to install them.

[xpwarrior]

When I put on my sponsons I just went to the hardware store and bought expanding wall anchors that use a 1/4 inch bolt. These can be installed from the outside and are basically like the inserts used on the SLX. The other thing I did was use a belt sander on the sponsons where they meet the hull. I may have just got a bad set but they were not very flat and would wiggle against the hull. Belt sander fixed it right up. [img]smile.gif[/img]

[tomsl750]

Hey guys, I've got a 100% stock sl 750 (1995). I am turning about 6250rpm's at about 48-51mph on the dream o meter. Is this right for the stock set up. What kind of performance gains would I be looking at with K&N flame arrestors and a set of Boyesen power reeds?

[Lenchmob]

That is real good for stock. My stock SL750 would barely hit 50. I put prok f/a's and a jetlyne water box on it. It now hits 51-53 consistently. My rpms are 6350-6360. I also put the boysen reeds on there. It really improved the throttle response. Be sure to get the two stage reeds. The dream o meter is actually a pretty good speedo compared to other skis out there that use a paddle wheel for speed ratings. Your ski sounds a little better than what a stock ski should be running.

[SeaLion]

F/A and reeds are a good mod for the SL750. I would go 1 step further and add the 3/8" reed cage spacers while doing the reeds. It will boost performance and also add alot of longevity to the aftermarket reeds. Also consider removing the chokes and adding a primer kit and also going to 40:1 pre-mix by getting rid of the oil injection.