Ride Plate/Pump Shaft Sealing

[timhood]

My ride plate is not fully sealed. I believe this is why I have a slow hole shot, where the boat hits max RPM but doesn't gain a lot of speed, then the RPMs drop some and the boat picks up speed and RPMs. I have no trouble reaching max speed or RPMs. I'm looking for tips on sealing the ride plaate (what's the preferred material, anything special with the procedure, what else should I do at the same time, etc.). Also, I assume I should seal the entire perimeter? Finally, does the same go for the pump shaft? Photos attached.

 

[jombie]

I've been experiencing the same problems but it appears everything is still fully sealed on my boat.
Basically I'm interested in what everyone has to say in case I need to reseal.
thanks.....

 

[timhood]

Lacking any other reply, I suppose in the off-season I'll probably take off the plate and intake grate, sand and re-paint them and fully seal them. I'm not motivated to do anything now that might jeopardize missing an on-the-water day.

 

[Macster]

I've seen photos and threads of guys sealing the bolt holes on their ride plates but not usually getting upinside the pump. Your photo shows a lot of excessive silicone - possibly removing that could help.

Have a look on Green Hulk, there's plenty of threads there on how to do it and what products to use.

Apparently, on average it gives a 1mph gain in top end speed. In my opinion hardly worth the effort.

 

[timhood]

I'm not interested in improving top speed. It was my understanding that slow starts due to cavitation, where the engine revs to max RPMs quickly but doesn't take off quickly, then the RPMs drop some and the boat starts to move, was because of some kind of leak in the seal or because the plate wasn't fully sealed. My boat doesn't have any problem reaching 8100, it just doesn't get off the line very quickly.

 

[thor7000]

Have you checked your wear ring?? I have the same problem on my speedster200 and will be re-caulking everything next week. I purchased 3M 5200 sealant from West Marine, everything that I have read states it's the best for the job. I would seal around every joint/lip of the ride plate and the shaft guard. I just recently removed my pumps and had new wear rings replaced, but I re-used the old neoprene seals without using any of the Locktite 454 gel, so I am also going to pull the pumps again and replace the seals. I also bought 2 tubes of the Locktite 454 gel to use on the seals....hopefully that fixes the problem.

 

[timhood]

Without taking everything off (I did take off the venturi), I shined a light and couldn't see any real wear ring damage. Maybe ever-so-slight marks, but almost imperceptable. The clearance between the impeller and the wear ring was tight. I couldn't get a decent photo to post. I think I'm going to follow the ride plate seal option and see if that helps. It seems like an easy inexpensive route.

 

[Macster]

Keep us posted.