97 787 rebuild

[russianphil18]

I have been rebuilding the 787 for about a month now. the reason for doing it was cause it wouldnt start and one of the cylinders was showing 90 compression while the other 155. well the top of that piston had dents in it everywhere ands even in the head. I pulled the piston off thinking that was the only problem and saw that the rod was moving up n down. I pulled the engine and while it was upside down to start to remove the bottom end i noticed metal was falling out of it. Obviously thats never a good thing. i was guessing that the pieces of metal were from bearings.
Pulling the bottom end off was more work then i thought. the starter housing is in the way of one bolt so the flywheel and that whole side had to come off. bought a flywheel puller and got that off today.
I found that the bearings on the bad rod dont exist anymore but i also saw that the rod doesnt have any bolts on it which would allow me to easily remove it. the rod is a solid piece attached to the crank. I have never seen this before so any help on how to get that off would be great.
The other bad thing is that the rotary gear is eaten up. how should i go about replacing that.
Im also looking for where i can buy a gasket set for the entire engine

advice? was/is this rebuild really worth it? i have pictures to show so ill try to upload the most important ones in as few posts as possible.

any help is appreciated. thanks alot

 

[russianphil18]

more pics

just one more post after this. sorry for the amount of pics, im only picking the most important ones. a picture is worth a thousand words so its better to see what i was explaining.

 

[russianphil18]

more pics 2

I hope these pictures also help who ever comes across this thread later. thanks for any help once again.

this engine doesnt fail to surprise me. the way the flywheel came of compared to cars is just so unusual and the way the rods are attached...also very unusual.

 

[Minnetonka4me]

The crank has to be pressed apart/together with special tools. Very normal in small motorsport engines. I would Recommend a reman from Seadoo.

The RV gear was taken out by a needle bearing; Your RV valve should have a huge ding in it too. Pull that circlip out, then get a nice big socket, a long 10mm bolt that has full thread and a nut, and a washer. Put the nut and washer on the bolt, stick it through the socket and thread it into the RV shaft...its got a threaded hole. Then hold the bolt head and tighten the nut. It will pull out. There is a clip you remove and then you can replace that gear.

I have good used heads for $80, and $60 for one that just has a couple dings...like 20. Totally usable still.

If you dont have a service manual get one...they are free if you become a premium member.

 

[DooWacka]

:agree:
The crank can be pressed apart and together with new rods, bearings, and seals. I have done it with fairly normal tools and a press. However, the real trick is aligning the various crankshaft "pieces" after it is back together. You most likely have local shops that work on these small motorsport engines (motorcycle, snowmobile,...) that can do the alignment. They have a special jig or a lathe to hold the crank so you can rotate it and "tap" the throws into the right "balanced" positions. There are a few sites online that give info on the "art" of crank re-alignment.

Unless you really want the experience, Minnetonka is right, that a reman crank is a much easier way to go.

787 crank rebuild kits (bearings, rods, seals) are about $200.
Crank alignment probably about $150.
Rebuilt cranks about $500.
Rebuilt 787 motors about $800

Good luck and have fun.

 

[From_me2u]

Crankshaft seals

Hey great pictures. Im also just rebuilding a 787. I was looking for a picture of a crank and found just what I was looking for from your post. I trying to figure out if there are crank seals on the mag side of the crank shaft. I didn't take the engine I have apart, so I'm not sure if it's missing or there not one there. It looks like your picture don't show one either. I'v looked on parts list and can't see one there. So I'm kinda thinking there's not one. Is this right ?

 

[Minnetonka4me]

The crank seal is pressed into the mag housing. You will have a paper gasket between the housing and the cases too. So what you have so far is correct.

 

[From_me2u]

Thanks for the fast reply.:thumbsup: I got it now. Had some how over looked that big piece ( under work bench ):redface: Got a little tunnels vision. The engine Came in 3 boxes, So I keep thinking " I must be missing parts "all the time.

 

[Minnetonka4me]

There you go...no problem.

 

[russianphil18]

more help

if you need a closer picture of that area i can get that for you but the description is correct.

Im hesitant about getting a reman crank cause i dont know what shape it will be in. the one i have i know is good but i just need to change the rod. How can i remove part of the crank that is on the flywheel side up to the rod so that i can take the rod out and put in the new one then press it all back together. I bought a standard two arm puller but it is not pulling the crank off cause the bearing is in the way of the puller being at the center.Where can i find these parts:
rod + seals or washers
bearings
complete engine gasket set
rotary valve gear
piston

or where can i find a new engine?

I also need some tips on how to put the piston back on the rod with the bearings. it seems like once u take it off its impossible to put back on. the picture shows how i want to pull the crank off the piece that holds the rod. If its doable please let me know how. thanks

 

[SabrToothSqrl]

Your in Philly, right?

so your fairly close to this guy:

http://seadooengineshop.com/

I'm sending a 2nd engine to him this week.

Was impressed with the first one, but I haven't had it on the water yet... what with it being 19 degrees this AM.

 

[Minnetonka4me]

A reman crank will have all new bearings, seals, and rods if you order it thru BRP.
I think sabr though...since that company is close enough not to ship, it might be the best option for you.

 

[SabrToothSqrl]

Up to you, but what's the cost of the part + doing all that work only to have something not be 'right'.

After 3 engine failures rebuilding on my own... I gave up.

I'll do everything to a ski, but the engine. I defer that to people with more tools and skill.

Crank + top end + time + no warranty for me was NO fun, and within a few bucks of these prices...

 

[russianphil18]

Thanks alot for telling me about SES. I took my engine to them and got it back and its now back in the jet ski. The engine looks fine as of now but once i break it in and run around on it for a lil ill write on here again. as of now i recommend SES and hopefully my opinion doesn't change after i run around on the ski for a bit.

My question now is.....I dont remember where my oil hoses go. also do i need to suck the liquids in the hoses up to the ends so that the engine doesnt need to run dry for a few rotations. the first time i start it, what should i do? maybe oil in the gas, maybe some gas under the spark...any suggestions? thanks

Can someone write on here what my carb settings should be for the idle, low speed, and high speed. just a rough description of how many turns off of fully turned in. This will be for the break in period until i start the tuning. thanks alot