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787 rfi plumbing question

benaspx

Member
Hi All,

sorry this is probsbly a dumb question

Son wants to be a marine engineer so we bought a dead ski to do up.. We're reassembling our 1999 gtx RFI after engine rebuild and we've got a little stumped when plumbing in pipes.

The shop manual shows a different configuration for cooling tubing than the pipes we had installed when ski arrived. The parts manual shows the correct layout for our ski so we're working from that, however embarrassingly there is one port near the flywheel on the throttle /airbox side which we just can't work out where it should be plumbed.

please see photo, its for an 8mm hose
 

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Dang no one replied yet. :) Cooling water hoses are pretty simple for the RFI. The hose that comes out from under the rear of the engine cooler connects with a TEE to the hose that comes from left side (facing front) of the engine. This hose drains the cylinders. Here are a few pictures. Hope this helps.

Engine Install GTI 787 RFI (2).JPEG


GTX RFI Engine PTO Lined up.JPG

RFI Engine Start up  (4).JPEG


Oil Tank Line cleaning (10).JPEG

20180917_165820.jpg


Engine Bay (1).JPEG


😊
 

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That small line on the red engine where you have the arrow is the air line that provides pressure to open the rave valves. There is a check valve in the line. Need to make sure the check valve works. That air line connects to the rave solenoid.

GTI RFI Rave Solenoid.JPEG


RFI Engine Start up  (5).JPEG
 
You didn't pick the easiest ski to work on. Better pull the fuel canister in the tank and replace the filters. Good Luck !!
 
You didn't pick the easiest ski to work on. Better pull the fuel canister in the tank and replace the filters. Good Luck !!
It was the check valve I was missing, I had worked it out in the end, Plumbing wise it was weird that the shop manual differed from the parts manual diagram.. I went with the diagram from the parts manual because it matched the pipes already in the ski..

"You didn't pick the easiest ski to work on" tell me about it brother it's been a journey.. we were told all the ski needed was a new starter motor needless to say that was not the case :)

we got the ski working last christmas with a new starter battery and clean up.. and realised there was quite a bit more to our problems, garage said engine needed a rebuild and thats when the journey really began.. we wanted a project to teach us something new and have a cool toy at the end, we got a lot more learning than expected :)

replace oil tank
2 x split freeze plugs
3 x melted resonators
pistons worn,
seals gone
low pressure on both cylinders
sand throughout the engine cooling jacket
multiple seized snapped bolts and corrosion on underside of engine - so replacement crankcase
while we had the engine apart we did the marginal bearings on the crank and balancer

knowing what I know now I'd have walked away from the project.. but as it was my son and I just fixed things one problem at a time only to find the next problem waiting around the corner.

Everything is plumbed and wired in and now we've discovered electrics are non responsive... Argh!

We wired in negative to crank case, positive to starter, we're getting no beeps or action from the instrument cluster, checked the fuses Mpem and in the rear electrical box all good, had a multimeter on the battery and thats fine fully charged and only a year old.

when we unplugged everything we bagged all the connectors so there was no moisture / contaminants it was all working when we last unplugged it have no idea what has changed.

Any ideas ?

Many thanks for your time, great photos by the way it was helpful and reassuring to sanity check our work :)
 
I write some stuff up later. I fought the RFIs extensively. They can be confusing. Great skis though.
The ski is running :) cleaned all the connectors and earth cables, plugged it in and everything worked first time.

when running on a hose pipe does the ski eject water from the little tell tail spout at the back of the ski? there was nothing coming out, checked plumbing against the manual and your photos and it all looks good. could there be an air block somewhere?

many thanks

Ben
 
I can tell you my 98 GTX LTD does but sometimes its very little. I would say get it on the water and ride it or put it in the water on the trailer, run it and see how she does.
Also, as a friendly reminder, don't run the ski long on the hose, it doesn't cool other part of the ski. The driveshaft components can get really hot, really quick. I would suggest not more than 30 to 40 secs tops....IMO. It is really meant for flushing the system but if you need to do a quick diagnosis on the the machine it can handle that, just let it cool between checkouts.

Good luck
 
GREAT !!! Glad it started for you !! For the tattle tale at the back of the ski. Water should shoot out pretty good because you're under hose pressure. You might have a plugged fitting at the pipe connection or the hose. I use a air hose with about 40 psi. and check all the hoses and fittings. I don't like surprises when I get on the water. As @Grim stated on the water at idle you'll get very little flow out of that tattle tale. When you speed up you'll get a good squirt.

As @Grim stated you don't want to run the ski long out of the water. The water seal will get hot. Better to drop it in the water for testing and... you never know what it is going to do till you put it in the water. That is the real test.
 
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