Everyone Please post one Speed Trick

[Prism]

Raise the jugs to raise port timing with a made spacer or by stacking 3-4 base gaskets & copper spray. Then measure the squish and figure how much needs to be milled to get to .037"-.040"... Instead of milling the head, mill the jug tops instead. Remeasure the squish and tweak compression/squish from there with head gasket layers or milling the head slightly if needed. If done properly it should be close to 150psi without head milling and perfect squish. Chamfer the top of the bores slightly with a diamond bur and dremel (hardware stores or Walmart) this is to maintain head sealing. Raising the jugs is like putting a cam in a 4 stroke. Peak power is achieved at a higher RPM with equates to spinning the prop faster... All of us reading this thread are searching for RPM and horsepower. This mod fits the bill nicely...especially if money for a professional port job is in short supply. This is done all the time with go carts and works great for GPR's as well.

[Reaper9789]

When removing rideplate, tab, intake grate, and pump shoe bolts for the first time, don't just use heat. Go find a cheap-o adjustable pressure impact wrench to help vibrate the bolts out too, and helps avoid the odds of spinning an insert.

Just hit the bolt with some heat, then use the wrench to loosen it a bit, then more heat, then the wrench again.

I took my parts off this weekend, and the amount of salt corrosion on the bolts was amazing when I was using the wrench to vibrate the bolts out.

I gave up looking for some info on this, and decided to read every post in this thread.. Im taking my shoe off today to fill in the spot where the black felt gasket blew out.. Cavitation sucks.
Im stock with D plate and premix.
I want to get up to near 70 at least.. last check was 58mph gps before the felt gasket blew out..

[Spimothy Leary]

I thought the whole "superman" thing was dumb, until I tried it and gained 1.5 MPH on GPS...that said it was on a nearly empty lake, hit some sneaky rollers and about hyperextended my lower back!

dislocated my shoulder doing superman last year, same thing, sneaky roller,,,, god dam it hurt !!! had to pop it in on the shore and ride back.... I haven't done superman since.

[Flying Scotsman]

Personal choice.I also saw 1.5 mph when laying on the seat.If you do chose to do it make sure your ski is dialed in and you have a good intake grate/pump set up.

[munther abdulla]

alot of great info here

[munther abdulla]

what is the best ride plate for the top speed ?

[riick370]

what is the best ride plate for the top speed ?

Jim's cut R&D with at least .950 rise.

[XLT Chad]

Depends on what ski its going on.

[GGG]

Just reading through this thread. Thought I'd ad that the throttle blades ARE adjustable. You use the first carb as a starting point and loosen the 2 Allen screws on the throttle arm on the other 2 carbs to zero them out

also make sure that the throttle opens all the way. the cable may be out of adjustment. full throttle on my ski was about 3/4 on the throttle bodies. check this by pulling the throttle to wide open and see if there is any free play in the cable that is showing . this is easy to see up on the grip of the gpr's

* Yes, and on that same point, when you have your carbs on the bench, check to see if they are all 3 throttle butterflies are synchronized.
Adjust the linkage couplers as needed.

* Also, if you rejet and get rid of the choke plates, use that adjustable linkage on the choke plate for the throttle plates. The throttle linkage is non-adjustable.

* See pic below of Cajundude's carbs

[Roberd42]

Everyone here is posting to get the Jims ride plate ff mod. Is the ff mod to the stock ride plate as good as the mod to a riva or r&d plate for speed? I've got an island racing modded ride plate on my 2000 gpr GK1390 with 1200 r&d grate and pump stuff kit, and I'm seeing right at 69mph. I'm in the middle of a rejet now tuning the motor, only an hour or so after break in now so I know it needs some time. I plan to smoke over the nozzle, sand the hull and check for imperfections. What is meant by truing the hull and how do you go about doing that? Also, is there a ball park measurement to start on the ride plate to pump shoe/grate, or front to rear to shim to? I understand the side to side alignment. Sorry for all the questions but I think with a groupk 1390 jetted up I should be in the mid 70s.

[Prism]

Use a 2 stroke oil with an oxygenating ingredient (nitromethane, nitropropane, nitroethane) and tweak the EFI or needle settings. The one company that I know of with such a product is www.powermist.com look for SuperX under the lubricants tab.
(By the way, this company started because the owner and his father were into drag boats and are both chemists)

[GoFastGuru]

all you big bore monsters get a seadoo throttel cable that came on some of the old seadoos that came 1 to throttle split in to 2 hook one to throttle hook one to carb linkage the other to oil pump put bead on pump end holding pump turned a littel stock cable will not give you enough oil on low end and idle faster out of hole pump gives plenty on top end better oil ratio across the board kerry trick at least 1 to 2 mph

[Bimmerboy12]

Higher octane usually has an impact. unfortunately water conditions, temperature, humidity can all impact more that that.

[Hotrodaxel1976]

Lose weight is a healthy choice for some, either Hull or self.