Dominator Jet Pump needs attention

[nodigg]

Who are the go to people in Lake Havasu these days for Jet Pump work? (Model 12 TD A)

 

[rivrrts429]

I would reach out to Peterson Specialties or Kornowski for who those guys recommend.

Out of curiosity what attention does the pump need?

 

[nodigg]

So far, it seems likely a bearing failure due to lack of grease to the zerk from what little I know about pumps. BUT, I can hear a slight grinding noise just behind the U-joint it seems.

 

[RACER J]

So far, it seems likely a bearing failure due to lack of grease to the zerk from what little I know about pumps. BUT, I can hear a slight grinding noise just behind the U-joint it seems.

If the bearing went out, make sure you cut the engine oil filter apart also and look for metal. That bearing keeps the thrust off the crank.

 

[nodigg]

This bearing is outside and behind the flywheel/the motor, and behind the U-joint so no chance of engine oil contamination that I can figure out.

 

[SW_GLASS]

Harold Bruce at R&D Marine rebuilt my Dominator 12S pump a few years ago and I am very happy with his work.

 

[redone76]

This bearing is outside and behind the flywheel/the motor, and behind the U-joint so no chance of engine oil contamination that I can figure out.

What he's saying is check the oil filter for bearing material because that bearing on the jet pump keeps the pump from trying to shove the crankshaft out the front of the engine. Happened to my brother when that bearing took a dump. Had to rebuild the bottom end as well

 

[RACER J]

This bearing is outside and behind the flywheel/the motor, and behind the U-joint so no chance of engine oil contamination that I can figure out.

It wouldn’t be from contamination, it would be from taking out the thrust bearing in the engine.

 

[jetboatperformance]

This particular Dominator drive is "uniquely" easily serviced (by design) with some basic skills and if I can help feel free to call

 

[nodigg]

It wouldn’t be from contamination, it would be from taking out the thrust bearing in the engine.

AHHHH yes now I see.

 

[nodigg]

This particular Dominator drive is "uniquely" easily serviced (by design) with some basic skills and if I can help feel free to call.

I am supposing the pump has to be removed to replace or inspect the bearing?

 

[nodigg]

This particular Dominator drive is "uniquely" easily serviced (by desann) with some basic skills and if I can help feel free to call

Can you direct me to any manuals or videos to help?

 

[jetboatperformance]

I am supposing the pump has to be removed to replace or inspect the bearing?

No thats the unique part , The TD = "Transom Drive" unlike the majority of jet drives Its designed to allow basic repairs in the hull without removal of it or the engine I take calls 7 days a week happy to help , my shop phone rings to my cell

 

[Your ad here]

I wanna say the dominator pump on the Commander I had, had splines on the driveshaft between the flywheel/flexplate and the pump. That would prevent any forward thrust on the engine, unless it bottomed out.

 

[nodigg]

I wanna say the dominator pump on the Commander I had, had splines on the driveshaft between the flywheel/flexplate and the pump. That would prevent any forward thrust on the engine, unless it bottomed out.

Well, that's interesting since it is on a Commander as well!

 

[traquer]

D1 performance actually does excellent jet work. Not sure if he still works on em though. Or just talk to the guy above!

 

[nodigg]

D1 performance actually does excellent jet work. Not sure if he still works on em though. Or just talk to the guy above!

Been on the phone with Tom. Very helpful.

 

[rivermobster]

Been on the phone with Tom. Very helpful.

He's alright.

 

[jetboatperformance]

He's alright.

Bite Me

 

[lbhsbz]

This bearing is outside and behind the flywheel/the motor, and behind the U-joint so no chance of engine oil contamination that I can figure out.

You missed the point...that bearing supports all the thrust load from the pump....when it goes away...and they do, all that thrust is put into the crankshaft and tries to push out the front of the block. It takes about 30 seconds to kill the engine thrust bearing and the crankshaft after the pump bearing goes away. The oil filter will be full of the rear main bearing from the engine...not the pump thrust bearing.

First like of defense is the impeller hitting the pump housing...but that doesn't last long before the housing is junk, the splines are bottomed out, and then the crank takes all the load

 

[Your ad here]

You missed the point...that bearing supports all the thrust load from the pump....when it goes away...and they do, all that thrust is put into the crankshaft and tries to push out the front of the block. It takes about 30 seconds to kill the engine thrust bearing and the crankshaft after the pump bearing goes away. The oil filter will be full of the rear main bearing from the engine...not the pump thrust bearing.

First like of defense is the impeller hitting the pump housing...but that doesn't last long before the housing is junk, the splines are bottomed out, and then the crank takes all the load

If you shift jet into reverse would it try to pull the crank out the back of the engine?

 

[Kbach]

If you shift jet into reverse would it try to pull the crank out the back of the engine?

Of course it would. Duh…

But only if you throttle it up too much in reverse.

Neutral is where the fore-aft loading on the crank is the least. Clearly.

 

[mash on it]

If you shift jet into reverse would it try to pull the crank out the back of the engine?

The pump/impeller still goes the same way, so no.

FYI, CJ7 transfer case front output yoke fits Berkeley and Dominator splines, and doesn't bottom out on the splines.

Dan'l

 

[jetboatperformance]

The only thing that changes from fwd to rev on a jet drive is the direction of water flow out the nozzle or back under the hull via a reverse duct (reverse bucket closes, nuetral=equal amounts + or - of water flow for and aft at the same time, the impeller always want to "push the pump shaft thru the bow" regardless of direction of the boat. The input to the jet is splined and the driveline has a mating female spline , when the jet thrust bearing fails there is nothing to control fwd. movement of the main shaft and eventually the uncontrolled fwd movement will wipe out the suction housing and can (like said) damage the crankshaft fore/aft thrust surface and bearing . A dial indictor and a careful push pull "prying" can tell if thrust damage is an issue (around .006 to .008 inches, specs differ )

 

[wzuber]

If the yoke, (the splined part that slips over the splined end of the pump shaft driving the pump impeller) if the end of it is open the shaft will not bind against it and wipe out the thrust bearing on the crankshaft. If that yoke is closed ended when cast/made then the pump shaft CAN push against it and transfer the thrust of the impeller into the engine after it destroys the wear ring, impeller and suction housing if ignored long enough.

 

[454Rocket]

I just tow mine all the way to Atascadero and go wine tasting after

 

[90 Laveycraft]

Thats what I did!

Post in thread 'Anatomy of a Jet Drive Failure' https://www.riverdavesplace.com/forums/threads/anatomy-of-a-jet-drive-failure.71336/post-1036320

 

[Your ad here]

The pump/impeller still goes the same way, so no.

FYI, CJ7 transfer case front output yoke fits Berkeley and Dominator splines, and doesn't bottom out on the splines.

Dan'l

The only thing that changes from fwd to rev on a jet drive is the direction of water flow out the nozzle or back under the hull via a reverse duct (reverse bucket closes, nuetral=equal amounts + or - of water flow for and aft at the same time, the impeller always want to "push the pump shaft thru the bow" regardless of direction of the boat. The input to the jet is splined and the driveline has a mating female spline , when the jet thrust bearing fails there is nothing to control fwd. movement of the main shaft and eventually the uncontrolled fwd movement will wipe out the suction housing and can (like said) damage the crankshaft fore/aft thrust surface and bearing . A dial indictor and a careful push pull "prying" can tell if thrust damage is an issue (around .006 to .008 inches, specs differ )

It was a joke guys. I may have used ski rope for tying to the dock, orange life vest as a flag, and the hot girls are my cousins but I do know the impeller spins one direction.

 

[mash on it]

It was a joke guys. I may have used ski rope for tying to the dock, orange life vest as a flag, and the hot girls are my cousins but I do know the impeller spins one direction.

No ski flag that doubles as a fuel gauge?

Slacker....

Dan'l

 

[Your ad here]

No ski flag that doubles as a fuel gauge?

Slacker....

Dan'l

Real jet boters don't have ski flags hence using the life vest in place of the flag. We aren't worried about running out of fuel as the engine will quit running shortly after spending 20 minutes on the ramp to get it started.