How is everyone? I just bought a GP1300 and I fell in love. I know its fast, but I would like a little more power for those times you run into someone with the same ski or a faster one. I don't race or anything, I just enjoy going fast. I see a lot of things in the Riva site that will help me. My only questions concern durability? How bad do these parts hurt your engine in the long run? Thanks

If you don't mind sacrificing holeshot for more top speed, you can just perform harmless hull mods. I find that most grudge races begin with both craft on plane, anyway. These mods include the pump plug kit, intake grate, impeller, ride plate, etc. With my parts below, minus the head, I made it to 68.5 MPH @ 7030 RPM. After adding a pump gas head, I reached 69.1 MPH @ 7070 RPM. This is an OEM head milled down by Riva to increase compression. It also helps get back some of that lost holeshot. The compression is still low enough that I can run 92 octane. I'm still going to try the GP800R intake grate, too. It's supposed to net 1 MPH, but again you lose some holeshot. There's always a catch. It depends on what you want.

A must, however, are the Waveeater(waveeaterproducts.com) power valve retainers. My ski dropped a PV after only 28 hours. Even if the damage is covered by the warranty, your ski will be in the shop when you should be out riding. Get yourself a tach and a GPS as well, so you know the results of your mods. I also recommend that you call Carl at Island Racing(islandracing.net). He'll get you up to speed.

Took the words right out from under my tounge. Also the good thing about this 1300r is the enormous potential this ski has by doing those hull mods, without even lifting the seat to your engine!!! I'm hearing 75mph already and the motor has not been touched at all. Not saying any names but he is what some would call on here the GP expert!!!

rhino...........I can't speak for the 1300R....yet. But I can speak for my brothers GPR that has a RIVA Stage 2 kit installed. He now has 113 hours on his 2000 GPR, no waveater clips, pump gas and has rode the "stink" out of that thing.

My recommendation would be to check out the RIVA kits and not vary from them at all. These kits are for both performance and reliability.....and from what I've seen you get both. The Waveater clips are a good insurance policy however.

Welcome to the Forum and GPR Heaven.

Rhino,
I suggest you enjoy your one year warranty. These are hi-po toys, that can/will break in just the right situations.

Read and participate, in the forum, and decide for yourself what you would like to try.

Be safe.

I would have thought that by making mods such as the 13-19 sb prop, ride plate and PPK that your hole shot on the 1300R would be increased, not ONLY your top speed. I hope so anyways. I don't want to have to chase my buddies on their Doo's for a mile before I am able to catch them.

Thanks a lot for all your help and info. My cousin called me last night to tell me he bought a ultra 150. I am not sure, but aren't they a little faster?

IF you are a rec rider..I say...to helll with holeshot. My riding buddy has an XP with a good bit of mods and he has Killer holeshot, and I catch him well within 100 yds. If you dont do closed course or other racing that requires a ski to jump out of the water, then go with the hull mods for top end. For comparative numbers my avg speed with the mods below (GP12R) is 68.5 mph, and I have never touched the engine or the carbs.

Do the waveeater clips & d-plate to prevent cat con failure.

Wouldn't the pump plug kit, impeller, ride plate, grate, increase the hole shot not slow it down? It these dont increase hole shot can someone tell me what does?

The pump plug kit, sealing the pump, and a new impeller (depending on which impeller) will all increase holeshot. The rideplate doesn't help holeshot, and the intake grate could either help or hurt holeshot depending on which one you buy. There is usually a trade off on intake grates. For example, the 800R grate will increase top end, but decrease holeshot.