Dreaded 4000rpm wait 4-8 seconds then goes Fast!

[NapaMatt]

93 Seadoo XP 657


I'll start here..

Fresh engine.

New crank
New pistons
New Rotary Valve
New Rotary shaft

new impeller
new wear ring


Rebuilt carbs Mukini kits
Black fuel lines with inline filter right before carb


I lined up the Rotary valve with the mark on the case. and MAG tdc .

Could i be off one tooth??


or half?


this seams to be a Normal problem with the 657 and timing..!!!


i can ride it .. but starting off.. it makes it right to 4000 some times 4500.. but says right there and pauses for any time.. 3-10 sec.. dependin on the load.. acts like it is loaded up..



when going full bore.. when u get there is kinda ok.. you hold it there it is ok.. full power is what i think, but no throttle response if say u let go just for a sec or 2 .. u have to wait again another 3-5 secs then takes off??


kinda boggy..!!!! no sudden acceration??


What am i missing...

any help here??

one guy said to try jetting.. the mains down a jet!
after he looked at the plugs?

it is stock jetting. stock air box


yes.. i lost one of my bolts off the carb throut too. yes. Ran great before????



thanks guys

 

[my787]

yes.. i lost one of my bolts off the carb throut too. yes. Ran great before????

Lost a bolt? Seadoo had that bolt there for a reason....

 

[scooper77515]

Did you do a pop-off test on the carbs?

I am wondering if your high speed circuit isn't kicking in on the carbs giving you the fuel you need for the higher rpms?

 

[NapaMatt]

rpms pop off

Did you do a pop-off test on the carbs?

I am wondering if your high speed circuit isn't kicking in on the carbs giving you the fuel you need for the higher rpms?

I first tested pop off.. Being at high 34 psi..

Then i lowered it to the right spec to 26...


Now it set at 16 seams a little better..

 

[seadooya]

lsa = 1.25

hsa = 0

Pop-off around 22-29psi, and your rv timing should be at 130/65.

 

[NapaMatt]

Tryed...

Yes pop off 22-29.. psi


Tryed that it got worse i thought more time delay..


you guys think my Rotary valve could be off..



All so in the garage.. out of water revs to 7000 rpm..


in the water i can only get 6000... maybe 6100 if i hit a wave..


Trying to only take the engine out one more time.. it is a chore that sucks!

hope this helps

 

[NapaMatt]

Going to try to jet the mains down one ...


i'll report back...

 

[NapaMatt]

hey..


Just to let u guys know..

Fixed my problem drop the main down from 125 to 120

HALLS ASS

 

[scooper77515]

Cool! Glad that worked out for you! :cheers: