01 GTS with new engine has no throttle response I am stumped please help

[xprider02]

I have a customers 2001 Seadoo GTS 717 in the shop. Ill start off with letting you guys know I work on PWCs daily and work on them for a living and I am stumped!!! The ski came into the shop because the customer put the wrong spark plugs in the ski and it burnt a hole in the top of the piston.



Before the customer put the wrong plugs in and blew it up the ski ran great



I sold the customer a premium SBT engine.



I installed the engine

Cleaned the carb and installed a rebuild kit with new fuel pump gaskets, etc

Blew out the cooling lines to get sand out

installed new fuel lines and fuel filter

cleaned the fuel valve

installed New plugs as well



The ski starts great and runs great on the hose

I put it in the water and it will start fine

run it in the water and it has bad throttle response

You can floor it from 0 throttle to full and it just gradually will get up to speed

you can hold it at 1/2 or 1/4 throttle for 1 minute then punch it and it will just gradually get up to speed

It runs good on top end

The excelerator pump is working

I tried new plugs multiple times

I checked pop off and tried every gram spring

I tried turning the low speed screw and high speed screw in both directions slightly and it made no difference



The carb has all seadoo recommended jetting straight from the manual and the exact same thing it had in it before a 75 pilot, a 165 main jet, 1 turn out on low speed screw, 0 on the high, it has a 2.0 seat and the needle is in great shape



I checked and the fuel pump holds pressure at 10 psi for 10 seconds

The needle and seat is not leaking any air when under pressure, (no bubbles)

I tried unplugging the voltage regulator and that makes no difference

I checked rotary valve timing multiple times and it is correct

Compression is 145 in both cylinders and I have checked that many times

The impeller is like new and so is the wear ring

the engine will turn over freely like it should by hand with the plugs out



Any ideas or comments will greatly be appreciated!!!!!!



Thanks

 

[xprider02]

anyone with any info to help would be appreciated!!

 

[NapaMatt]

Dealing with the same problem...


so let me know..

I am still thinkin it in the carbs or Rotary valve timing..


But both look great

 

[yamahammer man]

2001 seedoo gts

i have the exact same seedoo! i am having the same problem!! its about to drive me crazy!! I am a certified motorcycle , PWC mechanic and i CANNOT figure this out!!!! lemme know if u come up with something thanks alot

 

[Bills86e]

My guess is the Flywheel is the wrong one for the motor. A 650 & 727 are different
position keyways. If ya throw a timing light on it, I bet it is off the chart! Bills86e

 

[xprider02]

yea I am going to check out the flywheel timing...anyone else figure theres out?

 

[Bills86e]

587-657-657X-720 motor prob

SBT is a shotblock, Installer updates and corelates tolerance & spec, insures the
correct part in the application. Picking up a different part, like flywheel has been
done by pros & Joes alike. Its happened!

When you install the stator plate onto the motor it has two alignment marks at about 9'oclock, one on the stator plate, one on the engine cases. The marks have to be aligned. That sets the ignition timing position.

It is simple. Look for a line at the bolt slot on the 9:30 o'clock position of the stator when the stator is mounted so that the harness is in position to be clamped into place by the harness braket plate that goes on over the wires.

Now look at the left side of the case at the stator mounting area by where that 9:30 o'clock stator hold down bolt goes. See the line in the case ?

After you bolt the mag housing back onto the motor, place the stator in there so those two lines are alinged with each other and bolt down the stator. Bolt the harness bracket back on over the wireing harness from the stator. Place the mag flywheel back onto the crankshaft. Replace the mag cover. Your motor is properly timed.

Actually the "line" in the case is more of a "notch" because it is on the thin piece by where that slot goes. It can't be more than about 1/8th inch long.

At most, when I need to fit a questionable flywheel onto a crankshaft, I lap it in with valve grinding compound, clean it throughly and bolt it on, using a new woodruff key.
A blueing is applied to shaft to show the fit to the machinist during this action.

A machinist manual for taper fits will tell you that there should be no foriegn substances between the two tapers at all. Why ? because any substance will take up some space and the best fits are clean metal to metal fits. Appying The

Correct Torque is what melds the two parts from slipping. All Bolts torque are specified in your Shop Manual. Very Important to consult that.

A woodruff keyway is for locating the flywheel to the crankshaft position only. Bills86e

 

[xprider02]

Nope it is the correct magneto flywheel and stator.

The Stator is timed correctly. I checked it again just to make sure and it is correct.

I am stumped on this ski and losing money!!!!

 

[xprider02]

what aout exhaust? I highly doubt it but could there be anything there causing this problem?