Yamaha Jet Pump Disassembly - From Grant Browne YouTube

[Bruce]

I found this great video today

 

[Julian]

Added to the FAQ!

 

[Magic]

Here is one I like for quick dis-assembly of the pump housing...

 

[jdonalds]

Its' much easier if you leave the reverse gate on and pull the whole pump. Less things to take apart and put back together.

My photo sequence here: http://jdonalds.smugmug.com/Boats/Pump-Removal/23215801_Dn8g6J#!i=1871556138&k=RmhwG6Q

 

[jdonalds]

I just had to pull a pump today to remove two pieces of wood.

We took a ride on Shasta Lake yesterday. There was no noticeable debris on the lake during our 3 hours, but the launch ramp had a lot of small pieces floating around. There was no way to avoid them. When my son was driving the boat onto the trailer both pumps picked up debris. I had to lower the trailer into the water a bit more and use the winch to pull the boat onto the trailer. Today I crawled under the boat and saw whatever was in the starboard pump was no longer there, but there were two pieces jammed between the impeller and the pump case. I could see they were too tight to remove unless I pulled the pump.

The only thing that slowed me down was a need for a breaker bar. The four large bolts holding the pump were all very tight because I had used red LocTite when I put them in the last time, which was a few years ago. It only took about 30 minutes to complete the job.

It was good to see the impellers are still in near new condition even though I have sucked rocks into both pumps numerous times over the years. Eight years on the original impellers is very pleasing. These boats certainly are low maintenance.

 

[Julian]

@jdonalds Yeah...not many prop boat owners that can say they ran the same prop untouched for 8 years....

 

[Glassman]

@jdonalds Yeah...not many prop boat owners that can say they ran the same prop untouched for 8 years....

haha, you got that right! My buddies have been known to drop major $$ on props throughout the years! And I'll admit to having gone through several before I owned the Yamaha.

Great instructional videos, thanks to all for posting these up. Anyone ever yank the housing using power tools? Could make it a ten minute job from start to finish.

 

[Julian]

I used an impact driver for the 4 bolts....and my pump loosened up after a couple of nudges from a small rubber mallet. It is a really quick thing to do though....I thought it would be much harder. I had to repull mine as when I did it originally I didn't know I needed gasket maker to reassemble. Not sure it is absolutely required....but the specs call for it.

 

[Julian]

Just took a quick look at the last video....and no gasket maker mentioned there!

 

[Glassman]

Julian, I was thinking the same thing...not even a quick wipe with RTV, I would think that would be prudent.

 

[TechRider]

Nice vids, thanks for posting. Very helpful!

 

[COtoFLsurf]

Wow, this video (the second one, to be specific) just saved me a bunch of time and a bunch of money. Sucked up an entire milk jug this weekend, limped home on one motor in the middle of an intense squall, was never so happy to get the boat home and safely on the lift. As seen in the picture the entire jug made it past the impeller and jammed on the fins. After many attempts to clean it out, decided the backend needed to come off. Armed with the info in the video, I pulled the backend, cleaned out the mess, and reassembled in less than one hour. And that was being uber-cautious since I was working on the water (via handy "inflatable work platform", ha !). Plan B would have been the dealer, which would have been an expensive 2-4 week ordeal, made more problematic since I do not have a trailer. Thanks JBers, and another thumbs-up to this being a very straightforward repair.

 

[buckbuck]

Ha, that is a great picture, @COtoFLsurf .

 

[Mainah]

@COtoFLsurf - what kind of boat lift is that?

 

[COtoFLsurf]

Elevator lift by Ace Lifts, very common type of lift in the Keys. Rated for 10K pounds, so theorectically can slam it for surfing and just leave the ballast on-board for next session. (Kidding, I would not do that, but my wakeboarding buddy did that for years on his private lake in Tampa.)

 

[DBamaC]

I used an impact driver for the 4 bolts....and my pump loosened up after a couple of nudges from a small rubber mallet. It is a really quick thing to do though....I thought it would be much harder. I had to re-pull mine as when I did it originally I didn't know I needed gasket maker to reassemble. Not sure it is absolutely required....but the specs call for it.

Funny that you mentioned a gasket in the old thread. I don't ever remember that being mentioned on the videos I'd watch on the disassymbly of the pump.

I sucked up some wood earlier in the season. I pulled the pump and removed the debris, inspected the impeller and wear ring (looked pretty good...pics below) and reassembled...no gasket. Didn't think about it at the time. Due to family issues, I've only been back out twice. The first time back out I was making a little lower than normal rpm's and my top speed was down about 10 mph (5 adult occupants). Before I went out the second time I pulled the plugs, checked the gaps (were a little tight) and reinstalled as they were new may 10 hours ago. Got on the lake, same thing...top rpm's were just over 7K and top speed a little under 40 (6 adult occupants). My son was driving and I (oddly) was sitting in the center of the rear seat. The amount of water coming up on my back was way more than normal. Had a lot to think about on the drive home.

I'm thinking the lack of seal at the impeller is my issue. I've read some on syptoms of a failed SC clutch and my issues are not as severe as what's described (top speed in the 30's for a ski and rpm's in the low 6k range). I really don't think my impeller looked bad enough to cost me 10 mph and wouldn't explain the loss in engine speed (links to pics below from my post when I pulled the plug). I surmise the slight loss in engine speed is inefficiency being cause by the lack of pressue at the impeller.

Thoughts?

https://jetboaters.net/attachments/3a432e54-ba27-4809-a01b-497a88405fd7-jpeg.74799/
https://jetboaters.net/attachments/86e77b84-74a5-4182-a846-221b0fa6b1ee-jpeg.74800/

 

[Julian]

Funny that you mentioned a gasket in the old thread. I don't ever remember that being mentioned on the videos I'd watch on the disassymbly of the pump.

I sucked up some wood earlier in the season. I pulled the pump and removed the debris, inspected the impeller and wear ring (looked pretty good...pics below) and reassembled...no gasket. Didn't think about it at the time. Due to family issues, I've only been back out twice. The first time back out I was making a little lower than normal rpm's and my top speed was down about 10 mph (5 adult occupants). Before I went out the second time I pulled the plugs, checked the gaps (were a little tight) and reinstalled as they were new may 10 hours ago. Got on the lake, same thing...top rpm's were just over 7K and top speed a little under 40 (6 adult occupants). My son was driving and I (oddly) was sitting in the center of the rear seat. The amount of water coming up on my back was way more than normal. Had a lot to think about on the drive home.

I'm thinking the lack of seal at the impeller is my issue. I've read some on syptoms of a failed SC clutch and my issues are not as severe as what's described (top speed in the 30's for a ski and rpm's in the low 6k range). I really don't think my impeller looked bad enough to cost me 10 mph and wouldn't explain the loss in engine speed (links to pics below from my post when I pulled the plug). I surmise the slight loss in engine speed is inefficiency being cause by the lack of pressue at the impeller.

Thoughts?

https://jetboaters.net/attachments/3a432e54-ba27-4809-a01b-497a88405fd7-jpeg.74799/
https://jetboaters.net/attachments/86e77b84-74a5-4182-a846-221b0fa6b1ee-jpeg.74800/

It is entirely possible you could lose some, but I can't imagine it being much. Imagine what the tollerences are between those parts.. how much air or water could blow between them (or get pulled through)? I'll bet the racing guys ensure they have gaskets....but probably not many more. @Cobra Jet Steering LLC do you?

 

[Cobra Jet Steering LLC]

I always use red silicon very sparingly, especially where the cooling water passes through the pump sections but no one I know of makes any gaskets You should also use bees wax where the stainless pump bolts pass through the aluminum housings to prevent them from corroding and welding together. I learned to do this many years ago ok decades ago, when doing the trim bolts on Johnson outboards, I also used it on outboard water pump impellers to reduce impellor wear at idle speeds, wax won't wash off , a round wax ring toilet base gasket is about 99 cents . Good for drilling through stainless also

 

[Bruce]

@HockeyDave13, this video shows how to pull the pump.

 

[skyrme802]

J

Here is one I like for quick dis-assembly of the pump housing...

Very helpful as I believe the bearings have seized in starboard pump and is stopping rhe engine spinning. Feel more confidant to pull the pump off now

Thanks
Mike
South Wales
UK