Engine Rebuild advice for a 787 engine.

[Matt82]

Hi all,

I am newbie jet skier and am loving it but unfortunately for me last season, I had my jet ski towed in after a break down and I think water must of got into the engine.
I am thinking of doing an engine rebuild myself, but have never done anything like this before.
Now would I need to do a total engine rebuild or just a top end rebuild?
And is there any guides to removing the engine from the ski as I need to replace the starter motor as well.

Thanks.

 

[chucked]

Imho a sea doo engine rebuild is not for rookies.

 

[racerxxx]

If you got water into it, your in for a full rebuild. Crank, pistons etc.... As far as removal, I pull the exhaust, carbs, jet pump and drive shaft, disconnect the large oil lines going to the rotary valve and oil pump. Disconnect the main plug from the front of the magneto housing. Remove the bolts that go through the rear engine mount(2 of them one on each side going into the rubber mounts) and the one up front by the plug you just disconnected from the mag housing. Disconnect the ground wire on the starter and the hot lead to the starter. Remove the fuel line clamp on the starter bolt.

Here's a document on it:
http://www.shopsbt.com/pdfs/sd951.pdf

 

[Robj]

Time for a rebuild. Personally for me I rather get one of the shops to do it. Just do a search on this forum for engine rebuild and you'll get lots of info.

 

[racerxxx]

Time for a rebuild. Personally for me I rather get one of the shops to do it. Just do a search on this forum for engine rebuild and you'll get lots of info.

He's in the UK, a tad harder and more expensive.

 

[SabrToothSqrl]

if prices are that bad, can you find a running ski perhaps wrecked to pull the engine from?

rebuilding them is best left to a shop, I'm going to guess your engine is at LEAST 15 years old.

When you run a sea-doo or when you tow it, water is forced through the cooling system. When the engine is on, exhaust pressure pushes the water that's inside the exhaust system out the back. If the engine is not on, there is no exhaust pressure, and that mean old water finds it's way into your bare metal engine. causing rust, damage, and generally costing you lots of money. there are 3 things you can do, when you need a tow.

1. do not tow over 5 MPH this usually works fine.
2. pinch the line from the pump to the water cooling IN on the engine
3. start the engine after a tow on land. this will clear it of water (remove plugs first if you suspect significant water is in the engine).

I'm sorry to also say; you are looking at a full rebuild. Find a place that will also offer you a warranty.

You don't want a bill and a paper weight.

the 787 is one of the easier engines to remove / install, it's not very large, so you have room to work, and it's operation is fairly obvious.

while you are working on the ski, if your fuel over there contains any percentage of ethanol, you must replace the fuel lines as well. the grey colored OEM fuel lines are NOT ethanol compatible and will degrade and clog, starving the engine for fuel, and destroying it all over.

 

[Britrick]

Hi, where abouts in the uk are you? I'm near Brighton .

 

[Matt82]

Hi,

Thanks for your replys,
I am in Surrey near Heathrow so Brighton not far away.

 

[Britrick]

It's quite an easy job as long as you know you're way around a 2 stroke engine . Worst bit is all the seized stainless steel bolts that end up snapping, then having to be drilled out and re tapped !
Parts can be quite hard to get hold of in the UK and sometimes expensive , keep checking eBay .
This is a good forum , as the UK forum seems to be all about modern yamahas and stand up skis .

 

[Matt82]

Thanks for the info. Just out of interest what are the prices for a mechanic to rebuild the engine?

 

[Britrick]

Thanks for the info. Just out of interest what are the prices for a mechanic to rebuild the engine?

The sky is the limit, depends what they find wrong and how long it takes to get it all apart.
The crankshaft alone costs approx £350 gbp for a rebuilt one once you'res is removed or if you'res is to bad to rebuild a replacement is £500 gbp !