gp1200 max rpms and compression

[gp1200joe]

1998 GP1200 - stock engine, new solas impeller .

What should my compression be and what max RPMs? All three cylinders are above 100psi, throttle closed. max rpm on stock tach is 6900.

Otherwise ski runs fine, just haven't owned it for long and thought it would run a bit faster than 56MPH.

[CaptToyota]

Re: gp1200 max rpms and compression

Compression should be done with throttle wide open so engine can breath.

Should be near identical on all 3.

Is it 56 on the speedo or are you using a GPS ?

[GPkiwi]

Re: gp1200 max rpms and compression

Compression should be around 115 - 120 which is good. Max rpm's on the limiter is around 7050.

You should up alittle on speed, around the 58, all depends on impeller condition and ride plate, intake grate and sponsons and trim tabs. The motor has the power.but it's the hull setup that slows this ski. A good set up and you can break the 60mph!

[Tontsa80]

a little help

Hi guys! i just checket my cylinder preasures and all three showed 110psi...is that time to do something??

And other question is that, when i flush my engine most water comes out back and in front comes some splashes only:( when i drove it on sea , water comes out normally on front.. doeing something wrong?

PS. my stock gp1200 runs only 94km/h whit original speedometer, however it goes faster (only a littlebit) than my frends polaris whit has 120hp and it is a lot smaller than gp.

sorry bad english and greetings from finland!

My ski is gp1200 97´

[CaptToyota]

Re: a little help

And other question is that, when i flush my engine most water comes out back and in front comes some splashes only:( when i drove it on sea , water comes out normally on front.. doeing something wrong?

With the ski in the water, the pressure from the pump will make the "pilot" shoot more than home water pressure.

[Tontsa80]

Re: gp1200 max rpms and compression

Water thing is ok but what about the preasures? i know they must be allmoust the same but when it is too low?? like i wrote, mine is now 110 110 110psi.

[gp1200joe]

Re: gp1200 max rpms and compression

speedo - is that what it's called. I only trust GPS, that thing on the dash is barely useful. In fact, I'm not sure if the tach is much good either.

Since the general opinion appears to be that the set up does more than anything for speed, how do I balance the need for speed against the desire not to porpoise all over the place. When I first set the Riva ride plate I was getting higher speed, but totally uncontrollable porpoising.

[Tontsa80]

Re: gp1200 max rpms and compression

speedo - is that what it's called. I only trust GPS, that thing on the dash is barely useful. In fact, I'm not sure if the tach is much good either.

Since the general opinion appears to be that the set up does more than anything for speed, how do I balance the need for speed against the desire not to porpoise all over the place. When I first set the Riva ride plate I was getting higher speed, but totally uncontrollable porpoising.

Yes porpoising is most annoyance effect on gp1200. my ski whit original ride plate and pro-tec intake grate is horrible to ride max speed, it allmoust goes everywhere he wants. Gp should go faster but like you, i wan,t eliminate that porpoising first, even a little.

I have read somewhere that riva ride plate + R&D intake grate helps eliminate that porpoising a lot. iam goeing to try that set up next summer. That pro-tec intake grate is not good, but thats my opinion.

I drove in sea so there are waves allways, that can be different in lakes.:emoticonr