Rpm drop after 10s WOT

[kenneth.mccoy1]

I’ve got a 97 spx with a Groupk sleeper kit on it, it has R&D nozzle, groupk pitched concord impeller, trim tabs, worx intake grate, and sponsons. What’s happening is I’m going for some WOT runs, I’ll sit at 7080 for about 10 seconds then start dropping rpm. Harry said to richen it up so that’s what I did today, I started at 1 5/8 turn out pto and 1 1/8 turn out mag, but I’m at 3 turns out on the pto so I’m thinking I should go up a main jet size, do I go up 2.5 or 5.0? I also read on Groupks website that rpms sustained over 7100 requires an high volume pump, I’m kinda leaning towards that just to be safe. Other than the rpm drop it runs incredibly. Sorry for the long post, just trying to get as much info for analysis out lol

 

[kenneth.mccoy1]

Should clarify, it does this at every setting I’ve tried. Im going to go ahead and just replace the rectifier because it’s the original one and maybe that will help, but I doubt it.

 

[2strokeboy]

Check the carb Reference for correct high/low speed screws here.

Sea Doo PWC Carburetor Reference

 

[kenneth.mccoy1]

I have the correct main jets, groupk rejetted the pilots. I also noticed something weird on my rave valves, not sure if they did this or not but I’ll post some pictures

 

[Stevie96xp]

clean your raves my bet would be something other than carbs because if it was running out of fuel it would surge. Which I believe it’s not from what you’re saying. Sounds like you got a sweet setup there get it right she won’t do you wrong

 

[kenneth.mccoy1]

It’s a lot of fun! I’ll post a video on here so yall can hear what I’m talking about

 

[kenneth.mccoy1]

Just got off the phone with Groupk and they say I should pressure test the fuel system so I’m gonna do that now.

 

[kenneth.mccoy1]

He also said seadoo started slotting the RAVE valves on this model which doesn’t make sense to me because it seems like the slot would just allow exhaust gas back into the cylinder

 

[Stevie96xp]

He also said seadoo started slotting the RAVE valves on this model which doesn’t make sense to me because it seems like the slot would just allow exhaust gas back into the cylinder

O yeah pressure test is a good idea. Yeah slotting the raves that weird don’t know much about that seems weird to me my 96 xp raves is not slotted

 

[kenneth.mccoy1]

Yeah he said to try fixing the fuel system first before changing the RAVE assembly, I think I figured out the issue though, my primer tee was routed using the gas tank to carb line.

 

[kenneth.mccoy1]

 

[2strokeboy]

Yeah he said to try fixing the fuel system first before changing the RAVE assembly, I think I figured out the issue though, my primer tee was routed using the gas tank to carb line.

I would use return line for your primer it can cause bubbles if you use main line

 

[2strokeboy]

He also said seadoo started slotting the RAVE valves on this model which doesn’t make sense to me because it seems like the slot would just allow exhaust gas back into the cylinder

Do you have a picture of this

 

[mikidymac]

The slotted raves were to stop them from sticking at 4500 rpm. .
Some say they make a difference and some don't.

 

[kenneth.mccoy1]

I would use return line for your primer it can cause bubbles if you use main line

I routed the primer line to the ON fitting and I have the carbs on the RES, but I think you’re right and that’s why it was doing that. Harry said even with oxygenated race gas, 3 turns out would be super rich.

 

[kenneth.mccoy1]

Do you have a picture of this

I do not sadly

 

[kenneth.mccoy1]

The slotted raves were to stop them from sticking at 4500 rpm. .
Some say they make a difference and some don't.

Ohhhh thank you for clarifying that, I was really curious

 

[kenneth.mccoy1]

I’m going to water test next week I’ll post how it goes once I do!

 

[mikidymac]

You really should have ON and RES functioning.
For the primer make a loop towards the bottom of the hull on the return line and install the primer fitting on the bottom of the loop.
The primers always fail and suck air, the return line doesn't care if it gets air in it.

 

[Stevie96xp]

Nice sounds like you found the problem

 

[kenneth.mccoy1]

Well I took it out today and after trying LITERALLY everything I could think of nothing worked, as a last resort I changed my plugs and that was the issue. It runs awesome now just gotta fine tune it now. I appreciate all the help guys!

 

[Stevie96xp]

Well glad you got it plugs do some crazy stuff sometimes

 

[kenneth.mccoy1]

Yeah man, I literally put the ski on the trailer and then I was like well I’ll try swapping it lol