787 RFI Problems

[Mr. Bill]

Why would the engine sound better out of the water because you changed the wear ring ?

Bill O'Neal
WCM

[srcpaint]

don't know, guess the prop was catching on the chunk of wear ring, causing the motor to seem like it was bogging, I put the ski in today and it ran like new, i'm still going to get a new battery too, I was very suprised, everyone elts who heard it thought it was a engine problem too

thanks
Bill

[Mr. Bill]

No, what was happening was the impellor was not connected to the water going through the jetpump and compressing that water to produce thrust. By having a huge gap between the wear ring and impellor the engine freewheels and instantly hits the rev limiter at just about any movement of the throttle lever. This causes the engine to hit the rev limiter which retards the ignition timing and puts the engine into limp mode ( running on one clyinder ) to prevent engine damages.
The same thing will happen if you suck up a plastic bag, get rope wrapped around the driveshaft ( even alot of fishing line around the driveshaft ) or if you severly bend the impellor blades, have a bad seal between the pump and pump support plate, ride shoe and hull tunnel, or a bad carbon driveshaft seal.

BTW, if your impellor is now bent even a little bit, it will soon need another wear ring. For cheap impellor repairs, click on the SBT advertisement on this webpage.. They send you a good rebuilt oem impellor that looks like new, you pull yours out and stick it into their shipping box, stick the pre-paid return label onto the box, and call UPS to come and get it, or put it into a UPS drop box. Your price is about $20.00 plus shipping. You cannot beat that deal !

Bill O'Neal
WCM

[x-track]

old thread ....but ....i have the strange problem that only one injector sprays ...if i chnge wires the other one spray ....if i measure i have 6 V on bot connectors ...but still only one spraying .

one thing i suspect ist that on the inner side of the flywheel there s a litte bit of xtra material added to the flywheel .....i thought as a means to balance it ...on this boat this piece of steel is missing .....can it be a trigger for the injector to open ?? thx , chris

[Chester]

old thread ....but ....i have the strange problem that only one injector sprays ...if i chnge wires the other one spray ....if i measure i have 6 V on bot connectors ...but still only one spraying .

one thing i suspect ist that on the inner side of the flywheel there s a litte bit of xtra material added to the flywheel .....i thought as a means to balance it ...on this boat this piece of steel is missing .....can it be a trigger for the injector to open ?? thx , chris

RFi runs on one cylinder at idle. You're good.

Chester

[x-track]

RFi runs on one cylinder at idle. You're good.

Chester

all right , thx ....that being mag or pto ??

[Chester]

all right , thx ....that being mag or pto ??

I don't remember. Does it matter?

Chester

[WFO Speedracer]

Actually it swaps from cylinder to cylinder every time it goes back to idle so it does not foul out a spark plug

[Chester]

Actually it swaps from cylinder to cylinder every time it goes back to idle so it does not foul out a spark plug

Makes sense, I didn't know that.

Chester