787 Rebuild or Replace?

[FireAsh]

Just looking for some insight on what the best (most cost effective) options are for me. I have a 99 Challenger with 787's and one of the engines is filled with oil, I've tried clearing it, but still won't turn over with the plugs in. I need to get this fixed, so what's the best option, have the motor rebuilt or just replacing it all together? Thanks for any help, FireAsh.

 

[Dr Honda]

How long has it been sitting?


The center seals can give up, and cause the engine to fill with oil. BUT... if it takes 6 months for it to happen again... then Work a little harder to clear it, and it may be fine. Then... when you park it for the winter again... put a "Pinch" on the feed hoses.

If this happens after a week... then, it's best to just replace the engine. IF... you can do all your own labor... you can save some $$$ by replacing the crank, RV shaft/seals... but if it's the original engine... the top-end is going to be warn. AND... there isn't any warranty. If you get a premium engine from SBT, then you get a 2 year no-fault.

 

[FireAsh]

This all started back in mid August, the boat sat from July 4th til then. I was going to do a compression test on the engine and found out the hard way that the engine was filled with oil. I do have a valve installed on the oil lines, but of course I forgot to close it. So basically in a month and a half, all the oil drained out of the tank into the engine. The boat has sat since then. Last night I took out both spark plugs and used a shop vac to try to clear the oil out of the engine, but as soon as I put the plugs back in, it wouldn't crank. I'm pretty sure the top end of this motor was rebuilt back in 2010 or 2011 before I bought it.

 

[Guest_User]

This all started back in mid August, the boat sat from July 4th til then. I was going to do a compression test on the engine and found out the hard way that the engine was filled with oil. I do have a valve installed on the oil lines, but of course I forgot to close it. So basically in a month and a half, all the oil drained out of the tank into the engine. The boat has sat since then. Last night I took out both spark plugs and used a shop vac to try to clear the oil out of the engine, but as soon as I put the plugs back in, it wouldn't crank. I'm pretty sure the top end of this motor was rebuilt back in 2010 or 2011 before I bought it.

at this point don`t reuse anything of the top end rebuild. you might as well start from scratch with a fresh complete rebuilt engine. either you send yours out if the core is in very good condition, or simply do an exchange with a company like SBT...

DITTO, Plus 1+ what the Doc said!:thumbsup:

this is of course you want a trouble free season. and you`ll also need to check every hose/clamp throughout the boat and take care of anything else along the way...

including the condition of the rotary valve and rotary valve cover...

plan on spending a lot of $$$...

Good luck...

 

[FireAsh]

Other than using a shop vac while cranking the engine, is there a better way to get the rest of the oil out of the engine?

 

[howie099]

Like other people suggested time to rebuild or swap that engine. It has been filled wth oil for like a year now. Plus your exhaust might have some oil in it to depending on where the rotary valve is positioned. You can suck the oil out with a hand pump or suringe. Think about the engine like this it will cost you about $500 to do the crank and about $1000 to do a whole engine w/1 year warranty yourself. You get a warranty with the whole engine the crank you get pretty much nothing.

 

[racerxxx]

Other than using a shop vac while cranking the engine, is there a better way to get the rest of the oil out of the engine?

Yep, pull the air box off and remove the flame arrestor. The open the throttle all the way, stick a 3/8" inside diameter tube through the carb into the bottom end and then tape the tube inside your shop vac. Wrap the tube and the end of the shop vac tube with duct tape. You now have a small but powerful shop vac.

 

[Stevego]

How long has it been sitting?


The center seals can give up, and cause the engine to fill with oil. BUT... if it takes 6 months for it to happen again... then Work a little harder to clear it, and it may be fine. Then... when you park it for the winter again... put a "Pinch" on the feed hoses.

If this happens after a week... then, it's best to just replace the engine. IF... you can do all your own labor... you can save some $$$ by replacing the crank, RV shaft/seals... but if it's the original engine... the top-end is going to be warn. AND... there isn't any warranty. If you get a premium engine from SBT, then you get a 2 year no-fault.

If you pinch the feed hose do you need to bleed the oïl pump before attempting to re-start? I have a similar issue and my tank is now empty after sitting all winter. I have not yet started the engine or refilled the tank. Should I be worried about bleeding it or just re-fill, let it fill the tube and start it up?

 

[howie099]

If the tank is empty you need to bleed the system.

 

[Stevego]

Whats the trick or easiest way to bleed it?

 

[Stevego]

How long has it been sitting?


The center seals can give up, and cause the engine to fill with oil. BUT... if it takes 6 months for it to happen again... then Work a little harder to clear it, and it may be fine. Then... when you park it for the winter again... put a "Pinch" on the feed hoses.

If this happens after a week... then, it's best to just replace the engine. IF... you can do all your own labor... you can save some $$$ by replacing the crank, RV shaft/seals... but if it's the original engine... the top-end is going to be warn. AND... there isn't any warranty. If you get a premium engine from SBT, then you get a 2 year no-fault.

If the seals give up, would the compression suffer? I ask because mine is consuming the oil but compression is perfect at 150 PSI. I have been told the oil pumps often fail, is this possible?

 

[howie099]

My one 657x in my GTX still had pretty good compression but the oil would fill the engine in few days from sitting. Most seadoo oil pumps or any manufactures pumps rarley fail. Mikuni pretty much makes all of them. Usually the little lines break or come off or people run the eninge with to low of oil and get air bubbles in it.

Most people go to pre-mix since it is easier to know you have oil and long as you put oil in the gas, but seadoo's need oil for the RV assembly so I say why removed it? You need the oil tank or a loop system you still need to check on. On a boat with 2 engines the oil pumps will save you money over the long haul. Only my Yamaha GP1200 is pre-moxed since yamaha's have a tendency loose the oil lines. That engine is not as cheap as most seadoo's 2-smokers are. You 2 engines cost alsmost as much as 1 1200 Yamy..

 

[FireAsh]

Turns out that the center crank seals on both engines were shot, so I had both the cranks replaced and finally got the boat back. Took it out for it's first run in over a year, so nice being back on the water.