motor is tight I need help

[jetski9010]

I was out riding my 760 superjet today and it was running great. I was out riding for almost 2 hours then all of a sudden my motor just locked up and shut off. I tried to crank it over and it would either crank super slow like to motor was tight or not be able to turn over at all. I towed it back and in the process of towing I flooded the hull.
When I got home I first wanted to check the flywheel to make sure it had not come off and was rubbing the cover or something because I just had it out to be lightning and I was having trouble with keeping it tight on the motor.
I check the flywheel and everything looked good. I put it together and tried to crank it over with the spark plugs out. It was hard to turn over for a sec and then it just turned over like normal with water shooting everywhere. I was thinking it just was flooded with water and that was my problem but then while I was cranking it it started to stop cranking and get tight again and then would crank over normal for 10 secs or so and then would get tight for a sec or two and back and forth.
Now it is tight again and I cant get it to break free. I looked at the flywheel again and the stater bendex and it looks ok. I tried to turn it over with a wrench at the flywheel and it is really tight.
I did check the pump too there is nothing stuck up in there. I cant figure this thing out and really dont want to tear it all down if its and easy fix. Anyone got any ideas?

 

[Mark44]

Sounds like you probably bent a rod, time to pull it apart.

Mark44

 

[junkyardj]

i guess the water is from when you got towed? hope its not hydro locked! good luck but sometimes its better to pull it apart rather than start it and cause more damage$$..

 

[jetski9010]

Sounds like you probably bent a rod, time to pull it apart.

Mark44

I was thinking that at first too but then somtimes it cranks normal.

 

[OCD Solutions]

If you did just a quick visual on the pump you may have missed some binding from the wear ring. Corrosion gets between the pump housing and liner and it swells, binding the impellor. Very hard to see but it will do exactly what you are describing. I had that on my SN years ago. I couldn't see it until I pulled the pump.

It would only take a few minutes to pull the pump and it would narrow down your problem. If that is your problem, then you can file it down for clearance and get back on the water but it will continue to swell so you should get a new one coming.

Whatever you are going to do, do it fast. after flooding that engine with water you ony have a few days before your crank will start to rust.

 

[Matt_E]

OP said it shut off and slow cranking before he towed it.
Sounds to me like it seized.

 

[jetski9010]

OP said it shut off and slow cranking before he towed it.
Sounds to me like it seized.

If it was seized then why would it sometimes crank over normal?

 

[Matt_E]

Because a seized engine can and will crank after it cools for a few seconds to a few minutes.

 

[jetski9010]

I got the top end off the motor and there was not anything wrong there. The motor is still real hard to turn over by hand with the top end off. I am about the pull the rest of the motor out now and check the crank out.

 

[blaster4life]

i bet a crank bearing is f-ed up........it will seat for a bit and roll fine but then it gets bound up and makes things tough

 

[jetski9010]

I got pistons off and the rod bearings are still good. I left my flywheel puller over at my friends house so thats the last thing I need to take off tomorrow but unless its some crazy thing where the flywheel is hanging up on something it looks like its got a bad crank bearing.
Also while I was taking this all apart I had seen on the inside of my pistons it says 61X00. The guy I bought this from told me it was a 760. Are there 760 pistons out there that say 61X00 or is this a 701? It has 62T cases and 61x cylinders. Is this what came on the 1996 superjet or did these cylinders come off a 93-95 701 superjet?

 

[blaster4life]

hahaha i ment crank....sorry few to many beers

 

[SUPERTUNE]

I got pistons off and the rod bearings are still good. I left my flywheel puller over at my friends house so thats the last thing I need to take off tomorrow but unless its some crazy thing where the flywheel is hanging up on something it looks like its got a bad crank bearing.
Also while I was taking this all apart I had seen on the inside of my pistons it says 61X00. The guy I bought this from told me it was a 760. Are there 760 pistons out there that say 61X00 or is this a 701? It has 62T cases and 61x cylinders. Is this what came on the 1996 superjet or did these cylinders come off a 93-95 701 superjet?

All years of Superjet's come with 61X cylinders...Measure the bore, stock 701-81mm, stock 760-84mm.