2002 GTI only getting 6500 RPM

[rweathers2001]

Have a 2002 GTI 720 that was running great but the seal on the jet pump went out and lost the oil. This caused the pump to go bad and had to replace it. When I did I got a new pump and a Solas 10/16 Concord impeller instead of going back stock. What I am seeing is the ski runs great but will only get to 6500 rpm wide open now. It also seems to have lost the aggressive feeling it used to have. The top end is still the same and it seems to ride much smoother now than before. I am thinking I may be over pitched and need to find a stock impeller to put back in it. Wanted to get some thoughts to see if this is the correct thing or just run it as it is. Thank you.

 

[etemplet]

Did you check your top speed and is there is any difference?

 

[rweathers2001]

Yes the top speed is the same or maybe a little faster as it was before. Right around 42 mph depending on the current. I have another 2005 GTI we run it against and they run right next to each other just like before.

 

[rweathers2001]

The main thing I wanted to see if it is safe to run if it will not get to a higher rpm. I don't want to harm the engine over time with this. With this setup it runs great. I tuned the carb some more and was able to get the hole shot better and the plugs look good. Thank you.

 

[POPPS]

Seems like you are over proped,,,you have same top end,,,but i am guessing you are not getting there as fast as before,,.

 

[rweathers2001]

That is what I was thinking also. I have only worked with boats and props so wanted to verify it was the same on jet skis. I have a new impeller on the way to test out. Thank you

 

[Lothsahn]

That said, you are running the right impeller according to solas' guide.

Maybe their impeller is just too aggressive or the other possibility is your engine is weaker than stock, if the compression is low.

For what it's worth, I do around 6680 on my 96 GTX with a Solas impeller, but I'm getting 54mph top-end (what you would expect), so it may just be how Solas engineers their stuff.

I don't think you'll harm the ski, either way.

 

[rweathers2001]

Thank you. I will reach out to them also to see if this is how they expect it to run also.

 

[rweathers2001]

I think I found most of the issue today. It looks like the new pump did not have screws to hold the wear ring so the wear ring was spinning in the pump housing. I put a new one in and put screws in to hold it. Now the hole shot is much better. Still have some tuning to do but I think this was most of the issue. Thank you for the help.