787 RFI rough running

[Seadoo787GTX]

Hey guys

My new to me 787 GTX RFI is driving me crazy. Rough running at lower revs (seems to rev up ok on trailer) and only 4700rpm in the water. Currently has maintenance light on too.

So far -

New rectifier (tried 2!)
New stator
New battery
Cleaned earth's
Cleaned Rave valves
New plugs gapped

The front plug come out really clean, like almost new but the rear was greyish like it should be. Both plugs wet.

I tested the coilpack primary side and got 0.020k ohms. Manual says it should be 0.41 ohms. I believe 0.020k ohms is 0.2 ohms so it's out of spec?

It sparks well out of the engine but wondering if it could be the coil? Can't get them locally (UK) and few weeks wait so that's this season gone for me.

Seems strange it revs so well out of water and would a bad coil bring on the maintenance light?

Thanks in advance

 

[POPPS]

If I read you correctly, a "grayish" plug usually indicates piston/ring damage,,,its the aluminum from the piston.

 

[Seadoo787GTX]

Sorry, I say grey but I mean the usual colour plugs should be.

So basically one good used plug, one plug not looking like it's doing anything but they're both wet.

Would a coil from another model fit? I know they're different looking but I can't get the right one anywhere in the UK

Thanks

 

[POPPS]

On the injected motors, the electric fuel pumps eventually become fuel delivery gremlins.

 

[etemplet]

Did you do a compression test? I'd check the fuel pressure and see if it holds. Fuel filters in the tank rarely get changed so they could be a source of problems.

For the rest, the best thing to do is print out the section of the manual on component testing and get busy with the multi meter. Send the fuel injectors off. I no longer use Fuel Injector man but he does good work. Check the fuel pressure. I have found the Air Pressure sensor can cause problems.

Make sure your little check valve and line that feeds the raves is operating properly. Check/test the rave solenoid.

 

[Seadoo787GTX]

I'm fairly confident its spark related, fuel filters all changed, new fuel (tank cleaned out) and also with head off and cracking, seems to be a nice atomised spray of fuel into each cylinder?

Compression is good also and even.

Do you have any further information on the check valve and how to test to solenoid please?

Kind regards