97 XP 787 WOT RPM Question

[GaiJin]

Hey All. I have searched the archives, and have not found an answer to my question. I have a 97 XP 787, stock motor, SOLAS Concord impeller (15/23), R&D Aquavein intake grate. Runs great, and has lots of pull. What kind of WOT RPM should I be seeing on calm / slight chop conditions?

I have checked compression (grounded plug wires, WOT) and get 135 psi on both cylinders.

I am seeing a maximum of 55 MPH on the "dream-o-meter" and around 6200 RPM on the tach. I used to see 62 MPH. I used to almost be able to keep up with my 03 XP DI, and now the 03 pulls away like all get-out.

Any ideas? Thanks

 

[GaiJin]

Hi Steve. Thanks for the reply. I should have clarified that it would almost keep up with my XP DI with the mods on it as noted.

I get the feeling that I am not getting full WOT throttle position, and have read many posts also referring to replacing the grey fuel lines. I am going to check my throttle position and such. Thanks.

 

[GaiJin]

Thanks Steve. I'm sure i'll figure it out

 

[Hokiebob]

Too rich, perhaps?

 

[GaiJin]

Thanks Guys. I am going to take things apart tonight and try and diagnose further. I probably won't have a better idea of what is going on until I can get back on the water this weekend. I'll post an update

 

[timmyboy76]

clean the raves. you run'n synthetic oil, also.

 

[GaiJin]

I took the air box off and checked my throttle linkages last night, and all is fine. It is getting full throttle. The RAVEs are the next thing on my list. As far as I know, they have never been cleaned. This machine has only seen BRP synthetic injector oil.

 

[GaiJin]

Well, I removed and cleaned the RAVE valves last week, and I must say that they were pretty clean to start with, and moved freely.

I took the '97 out on the water on the weekend, and monitored the RPM's while at WOT. I was able to get around 6800 RPM.

While washing the machine down after getting it back on the trailer, I noticed that the speedo pickup mount is cracked, and the left side rear of the pickup is raised about a 1/4". That might explain the low readings on the speedo.

So, I guess everything is OK with the machine.

Thanks All.

 

[Mike94ZLT1]

Well, I removed and cleaned the RAVE valves last week, and I must say that they were pretty clean to start with, and moved freely.

I took the '97 out on the water on the weekend, and monitored the RPM's while at WOT. I was able to get around 6800 RPM.

While washing the mashine down after getting it back on the trailer, I noticed that the speedo pickup mount is cracked, and the left side rear of the pickup is raised about a 1/4". That might explain the low readings on the speedo.

So, I guess everything is OK with the machine.

Thanks All.

Your speedo being cracked explains the MPH readings but doesn't explain why your other seadoo is now that much faster.

 

[jhjesse]

RPM's of 6800 is not bad...checked the wear ring lately?

 

[GaiJin]

Yeah, I replaced the wear ring last fall. I thought that maybe after I had changed the impeller that it was a good idea.

I have no complaints. The machine runs as it should. Actually, while out on Lake Erie last weekend, when the waves started to pick up a bit, I smoked a pair of 1200cc Waverunners! When they caught up to me after I had slowed down, they asked me if my machine was one of the new 255 HP Sea Doos! My response was simple.....1997 800CC two-stroke.....Next time buy a Sea Doo!

:-0