PTO Flywheel Won't Turn (93 Doo)

[SurfBeat]

While on the River my 93 Doo stopped. Starter would not spin; all I heard was a "thud" when I depressed the starter button.

Upon docking, I tried to turn the PTO flywheel - won't turn.

Someone on this site advised to pull the cylinder head, but did not advise what to look for when I did that.

Taking the advice, I removed the cylinder head.

Now that I've done than, what am I looking for?

To use my crystal ball, I figured, to faciliate further instructions, I removed the rear cylinder, since that looked like the easiest one to remove.

Everything looks very clean.

Should I be looking for rust or other abnormalities?

If not, what should I be looking for to ensure I don't have an engine seizure problem?

Maybe I should have pulled the jet pump first???

If I do that next, what should I be looking for to determine my jet pump is defective.

I am movign slow, but I would like to get this project done this week.

All help appreciated.

 

[kustomkarl]

It's possible the jet pump seized up. Since you gt the head off is the cylinder walls all scored up or real smooth? If the engine seized up it would cause damage to the piston, rings and cylinder walls. If the inside looks ok, it still just might be the bearings in the jet pump. Pull the jet pump and see if the impeller spins ok. If you can get to the PTO, put a pipe wrench on it to see if it will turn counterclockwise. With spark plugs out, or the heads off, be carefull not to strip up the PTO with the pipe wrench or hurt your hands trying to get it to spin. It has to be either the jet pump bearings or the engine seized up.

Karl

 

[SurfBeat]

Karl:

Thank you for the prompt reply.

In response to your question, "is the cylinder wall all scored up, or real smooth, it is the latter: Very clean, not scored at all. (I've been using Vavoline TCP since I purchased the Doo.)

The piston is smooth, rings look like new, and the cylinder walls are not scored.

Just to be sure I am reading your comments correctly, when an engines seizes, the cylinder will be scored as well as the piston??

I surmise, lack of oil causes an engine to freeze?

Based on the foregoing, can I presume the engine is okey dokey, thus, I can get out of my dungarees and get dinner ready for my man when he gets hom, then, tomorrow, pull the jet pump?


. If the inside looks ok, it still just might be the bearings in the jet pump. Pull the jet pump and see if the impeller spins ok. If you can get to the PTO, put a pipe wrench on it to see if it will turn counterclockwise. With spark plugs out, or the heads off, be carefull not to strip up the PTO with the pipe wrench or hurt your hands trying to get it to spin. It has to be either the jet pump bearings or the engine seized up

 

[kustomkarl]

Yes, if the engine seized it would score up the walls of the cylinder and drop pieces in the bottom end of the engine and cause it to "seize up"...lock up solid. If all looks smooth and clean. Reassemble the heads, and move to the jet pump. If those bearings seized, it would do the same thing as the seadoo is a direct drive from the crank to the jet pump. so it would stop the jet pump and the engine from turning over. Just by chance, look in the jet pump assy and be sure something isn't stuck in the impeller...you might decide to get a manual from our "premium section" to help with torque specs and disassemble and repair of the jet pump assy.

Karl

 

[SurfBeat]

Karl:

So, according to your theory of engine seizures, it is the metal shavings from the cylinder walls and/or pistons that is the root cause. Yes?

I shall surmise, then, that it is lack of oil that causes this problem? Yes?

Now, back to my problem.

So I can help others in the park that encounter a similar problem, was my procedure the correct one?

If the PTO does not turn, first pull the cylinder head AND cylinders and look for scoring?

If no scoring, then the next step is the pull the jet pump?

Of course, check for debris before pulling anything!

What causes the jet pup to seize; simply bearings going bad on a 16 year old Doo.

One last question.

Since I have a 587 engine, and the top end of engine looks brand new, I shall surmse the Vavolione TC-3 has been doing its job?

Maybe the APC oil is for the nest generation engines??? Whatcha think?

This gal rocks.

 

[kustomkarl]

well... if the engine seizes, from water ingestion or lack of oil or the wrong oil, it will cause a non lubriciation situiation and the pistons will over heat from friction and cause the pistons and ring to fail and score the cylinder walls when teh rings and piston over heat...the pieces usually jam in the bottom of the engine and wipe out the crank bearings in the process. If the engine looks ok, disconnect the jet pump from the engine and pull the jet pump to inspect the bearings and see if the engine turns over with the jet pump not connected. It is possible that water got in the jet pump bearings from a bad seal and caused bearing seizure of the pump. I wouldn't jump for joy yet, till you know exactly what went wrong and what is seized up.

Oh yeah...you rock girl! Good job so far.

Karl

 

[SurfBeat]

Karl:

Thank you so much for taking the time away from your family on a Sunday evening and explaining to this retired teacher what may have gone wrong with the PTO seizure on my 93 GTX, what to look for to find the problem, and providing a remedy.

before signing off toninght, I have a couple of questions regarding pulling the "cylinder."

Was pulling the cylinder wasted time and energy? Could I have simply looked at the walls on the cylinder and not fret about looking below, into the engine to check out the condition of the crank?I thought it would be the wise way to proceed, get a better look at the crank and into the bottom of the cylinder. Whatcha think?

 

[kustomkarl]

Usually if you pull the head off and the piston and cylinder walls look ok, it isn't an internal problem. If something went wrong internally and the engine and the engine stopped dead...it would show big time by puling the cylinder head off. Check out the jet pump to figure the problem and go from there. You still need to find out what exactly is bad and has the engine from not turning over. You have to be the eyes to see what is wrong. I can only give you my advise by what you tell me you see.

Karl

 

[SurfBeat]

Thank you Karl. Tonight my eyes will look at my Clymer's manual to get an idea how to pull jet pump. It can't be as difficult as pulling the carbs.

Again, thanks.

 

[hardtarge]

hey surf you'll find a few how-too for pulling the pump. Follow them but the physical pulling part is usually left un-answered

If you head down to your hardware store (home depot doesn't count) they do make Metric threaded rod

you'll need M8 1.25 2 rods and 12 M8 Nuts and 4 Fender washers Take one of your pump bolts with you to dry fit everything

cut it in half with a dremel or die cutter then clean up the threads with a Dye

take 2 boards use the reduction/steering nozzle as a pattern mark the holes on the board with a sharpie, DRILL

puller assembly

put 1 nut on the end of a rod about 1/4in then thread the rod into 1 of the 4 bolt holes 4-5 turns (it should be easy to thread by hand if it isn't you're doning something wrong, Cross threaded, wrong type of rod) is good then lock it down with the nut

do the same for the other three

guide your board over the rods followed by the fender washers and one bolt each

Tightening each of the 4 bolts in a criss-cross pattern will pull the pump away from the hull.

finding M8 Rod made this easy for me just look

why 12 nuts when you're done double up the nuts on the pump side of the rod over the end of the threads threads damage easy.