Hero or Zero?......"Resealed" my Jet Pump

[2kwik4u]

OK, Where's @swatski and @gmtech16450yz ?!??! I need someone to tell me I didn't just make a ginormous mess out of my pump housing.

Been fighting a cavitation problem under load when tubing. Might be technique on my part, but still bugs me. Put an L13 cone on a few weeks ago, lost some RPM, but still had the cavitation while turning/tubing. Read lots of talk of resealing the pump to keep cavitation at bay. So here's what I did about it.

Picked up some marine sealant. Finding 3M 5200 around here on a Saturday is like pulling teeth. Loctite has a comparable product, so I'm gonna give it a go:


Here are a couple before pictures. You can see a few places where there appears to be missing sealant, or maybe it has failed and been sucked out. Either way I can see where this is maybe not the greatest thing ever. boat has 48hrs on it I think, is just over a year old, and hasn't been touched inside the pump since it left the factory.


SO.....I got to work with the adhesive/sealant. I made a humongonamous mess. There is sealant on freaking everything. I wore latex gloves, but tore one. I think at one point I had multiple fingers adhered to each other. This is NOT something you should do on your back under the boat without good lighting. I pushed through and got the below results. Was really just trying to cover every seam that I could find with a good healthy coating of sealant. I smoothed what I could, but with only a finger to work with as a "smoothing device" it could've been done better I think.

Here's the results:


So there we go. Have I completely fubarred the pump? Is it not enough? it looks similar to what others have done, but this is the first time I've done it, so I suspect it's still not quite right. I'm anxiously awaiting some feedback from the experts. I'm headed out tomorrow with 4 adults and 2 kids. Should have plenty of time to tube and test so long as the rain holds off.

 

[Beachbummer]

I did something similar with 4200 and so far it has held, and resolved the issues I had. My worst offender was piece of old silicone that was interfering with flow. Hopefully your ailments are fixed!

 

[Speedling]

You did fine. Would have been far easier pulling the pump out though.

 

[Betik]

Please post an update tomorrow whenever you finthet come unstuck fro each other ( I always wear 2 pairs of latex gloves because I have been burned in the past)

 

[swatski]

OK, Where's @swatski and @gmtech16450yz ?!??! I need someone to tell me I didn't just make a ginormous mess out of my pump housing.

Been fighting a cavitation problem under load when tubing. Might be technique on my part, but still bugs me. Put an L13 cone on a few weeks ago, lost some RPM, but still had the cavitation while turning/tubing. Read lots of talk of resealing the pump to keep cavitation at bay. So here's what I did about it.

Picked up some marine sealant. Finding 3M 5200 around here on a Saturday is like pulling teeth. Loctite has a comparable product, so I'm gonna give it a go:
View attachment 75232

Here are a couple before pictures. You can see a few places where there appears to be missing sealant, or maybe it has failed and been sucked out. Either way I can see where this is maybe not the greatest thing ever. boat has 48hrs on it I think, is just over a year old, and hasn't been touched inside the pump since it left the factory.
View attachment 75233 View attachment 75234 View attachment 75235 View attachment 75236

SO.....I got to work with the adhesive/sealant. I made a humongonamous mess. There is sealant on freaking everything. I wore latex gloves, but tore one. I think at one point I had multiple fingers adhered to each other. This is NOT something you should do on your back under the boat without good lighting. I pushed through and got the below results. Was really just trying to cover every seam that I could find with a good healthy coating of sealant. I smoothed what I could, but with only a finger to work with as a "smoothing device" it could've been done better I think.

Here's the results:
View attachment 75237 View attachment 75238 View attachment 75239 View attachment 75240 View attachment 75241 View attachment 75242

So there we go. Have I completely fubarred the pump? Is it not enough? it looks similar to what others have done, but this is the first time I've done it, so I suspect it's still not quite right. I'm anxiously awaiting some feedback from the experts. I'm headed out tomorrow with 4 adults and 2 kids. Should have plenty of time to tube and test so long as the rain holds off.

You should be good and hopefully no/less cavitation. Will it hold? hard to tell. The last time I ported the pumps I used Marine Tex and then flapper sanders, it was a hellish job, and even that is not 100% after few months. But anything helps!
I have not figured out a way to not get 3m5200 on absolutely everything around me when I work with that stuff, but I guess that is what it is designed to do! So - if that Locktite stuff is similar, that's a positive. (yeah, explaining this to your wife is a different story, lol)

--

 

[Jgorm]

If it's like 5200 it takes days to cure. You could probably clean it up with a paper towel tomorrow.

 

[SamCF]

Here's a link to some info on transom plate sealing. I'm going to tackle this job next week.

http://www.greenhulk.net/forums/showthread.php?t=117375

 

[Ilmmct]

I’d have to say hero. I don’t have the mechanical prowess to comment on the results of your effort. But reading your post it’s obvious that you were working in a cramped space. Light was fading. You were operating with only one gloved hand. As the goop and gravity started making a mess of things, you pushed through to completion of task. So for this poll I vote HERO. Hope the cavitation was reduced and the 5200 was cured when you went out yesterday.

 

[2kwik4u]

Thanks for the replies and reassurances. It looks far messier than I had envisioned when I set out to complete the task. If it helps out a bit and holds up for the season then I might tackle a larger smoothing/filling project in the off season. I'll climb under the boat before launching and see if the sealant has cured up or not. I suspect it will be OK though. Lists 24hrs as a full cure time and I'll be around that at launch. It was already tacking up aignificantly when I posted last night. Hopefully I don't undo anything with today's use. I'll check on it when we get it home as well of course.

I considered pulling the pump, however I've never done that before and was more worried about screwing something up there before a family outing than I was attempting a reseal from below. Might add that to the list of things to attempt on a rainy saturday in the off season as well. Another one of those thing 's that everyone with experience says is easy, but still feels very intimidating to me. I've rebuilt rotaries engines and automatic transmissions before so I shouldn't be scared, but for some reason a mod to the boat has me as nervous as can be.

Looks like the rain will hold off for today. Inlaws are coming along and we have plans to meet up with some friends at the local lake. The typical group includes a dedicated wake boat, a couple pontoons, a few I/O runabout's and our jet. We usually end up with a group of kids that want to tube, so I should have some good amount of time to test. I'll be sure to report back the results of the sealing.

 

[njmr2fan]

Im wondering if this can be done with JBWeld and then smoothed with power tools / sanders? Or, do you not want such a permanent seal? Ive never thought about looking inside my pump to check this. I guess after 4 years this is where I've lost some of my speed and power?

 

[2kwik4u]

Im wondering if this can be done with JBWeld and then smoothed with power tools / sanders? Or, do you not want such a permanent seal? Ive never thought about looking inside my pump to check this. I guess after 4 years this is where I've lost some of my speed and power?

That is exactly what the two guys I mentioned at the top of the thread did. I'm not quite that comitted to it yet.

It appears that the sealant held just fine for my trip yesterday. Didn't put but about about 2hrs of use on it. Lake was super busy with holiday traffic so we didn't pull the tube any either. Basically just cruised out to the party cove, dropped anchor and socialized for 6hrs or so then headed back. Did get to launch a few times. No cavitation there, although that's never really been the issue for me.

Have a camping trip planned in a few weeks and there are some "watersports guys" going I'm told. Will try and talk them into heading out early one morning to try and get some good flat water testing done.

 

[2kwik4u]

Had the boat out again yesterday (against the will of my sunburnt back) and had some time to do a little testing. The results are good. Again, not a silver bullet that instantly made all in the world of jet boating right, but a small improvement. Had to break from the raft up to take the 6yr old to the marina. Was maybe a 2-3 mile ride, no big deal, but with just him and I (mom and the 2mo old stayed behind on a friends pontoon) I got some good top speed, start acceleration, and turning w/throttle input testing done.

Overall top speed is back up. Maybe a 1mph gain, might have just been wind helping me out. 43mph with the top up, flag out, windshield open, 2 coolers and a full tank of fuel. Typically would've been in the 40-41mph range with that load/setup, so it appears the top speed is doing just fine. Revs (I forgot to switch over to the digital rev counter, instead of the analog tach, that was dumb) were around 7500. Up from just above the 7k mark the last time out when I had just put the cone on. I'm assuming this is from the ribbon delete and not the pump sealing.

Dead start sees ZERO cavitation, but a little less "surge" than before all this started. Wondering if the cavitation let the revs climb higher initially similar to a loose torque convertor at the drag strip in a car?!?! No big deal, still plenty of grunt, just not the "hit" that was there before. It's smoother perhaps? Hard to describe for certain. Either way, this is no problem at all. I never had a problem with cavitation on launch, and I still don't. Have a camping trip coming up with some "watersports guys" that will test how well it does on launch. I'm 6'2"/225lbs so getting me up in deep water on a wakeskate is a tall order (I've bent several cheap ski handles in the past). The boat has never had a problem with that for me, but I'm experienced. We'll see how some inexperienced guys fair, and if I have to ramp up slowly to keep from yanking the handle out of their hands.

Now the biggest problem, turning while applying throttle. This is improved slightly. I didn't have a large load, however with say 50% steering input I could still add throttle and actually get some thrust. Full 100% turn input yielded more cavitation as before. This is is a little better than before, but still not 100% where I would like it to be. Perhaps it's just a jet thing?!?! Something else I did notice that is a big plus is the recovery from cavitation. Before, once it started to cavitate, you almost had to back off the throttle, let it gain traction then ease back into the throttle to regain speed. Yesterday all I did was turn straight and the pump caught back up and off we went. Once I get a chance to test with the tube and a full compliment of people I'll get some more solid answers. However, the initial results are pretty promising to make tubing a better experience. If the next outing proves otherwise I'll be looking for one of those powerball bungee things.

I suspect I could "tune" the entire system now for more revs with the L13 Cone, and some nozzle porting. Not sure if that's beneficial or not though for me. Not looking for more power or speed, just more "hookup" from the pump.

SO........Overall impression in case you didn't want to read that 1/2 novel I just wrote. Worthwhile mod/effort. For a couple hours worth of work, $7 in sealant, and the $300 L13 Cone I was rewarded with less cavitation and a few more mph. I'm curious if just the pump sealing and ribbon removal would have gotten me there, so if you're reading this in the future and trying to decide.......try the cheapest easiest stuff first and report back

 

[2kwik4u]

Reviving another old post.

I'm 4 days shy of exactly two years since I made this post initially.

Crawled under the boat tonight and snapped this picture. Roughly 70 hrs on the engine in those two years, and the sealant still looks pretty good and seems to be holding up really well.



Guess I'll check it again in two more years eh?

 

[ScottS]

Thanks for the two years follow up. Always leary of a bandaid fix - prefer to put in effort that lasts.

 

[2kwik4u]

Thanks for the two years follow up. Always leary of a bandaid fix - prefer to put in effort that lasts.

No worries. I hate when I find a thread with either no resolution, or no updates over time. I attempt to prevent that if I can remember.

 

[jEt_jAk]

I will be doing this soon. Is there a torque needed when putting the intake grate back on?

 

[2kwik4u]

I will be doing this soon. Is there a torque needed when putting the intake grate back on?

I Used about a 6 on the TFAR scale. My uncalibrated elbow clicked while I was putting it in, and I figured that was enough.

TFAR = That Feels About Right.

I suspect there is a torque spec, but I don't know what it is.

 

[jEt_jAk]

Got it. Did you use threadlocker?

 

[jEt_jAk]

Before and after.

 

[2kwik4u]

Got it. Did you use threadlocker?

I did not. Had some leftover silicone on it from the previous insertion by the shop. I had it replaced at the 10hr service because the original was broken.

Have you run the boat with the new sealed intake tunnel? Better/Worse? What product did you use?