Just one thing after another, 96 Sportster

[Apeman]

Thought I was done. But no. Just reinstalled the pump after rebuild. This is the 4th pump rebuild for me and never had any issues till this one. Took her out for a 30 minute ride to see how she behaved with the new wear ring and reworked impeller.
A little quicker out of the hole, and top speed went up 4mph. Put her back on the trailer, and opened the bilge plugs. A good two to three gallons of water drained. Before the rebuild, almost no water was taken on, even after hours in the water.

So, I'm guessing I'm leaking at the Carbon Ring or seal carrier? Everything looked great when it went back together. Haven't had time to open up an look, but plan to this weekend.
Any advice?

 

[mikidymac]

Make sure you have the rubber bumpers installed on both ends of the driveshaft.

 

[Dr Honda]

The carbon seal leaks by design. Seadoo's will always have water in them after a run. Make sure your bilge system is clear, and working.

With that said... don't assume... CHECK.


1) It could be leaking from the seal system. The tube in the back, where you clamp the boot could be broken. The boot could be split, the carbon ring could be cracked, or the O-ring inside the stainless ring could be split.

2) You could have a loose hose in the cooling system, or a rotted out plug in the pipe, and is putting water into the boat.

3) If you boat has the syphon bilge system... make sure the venturi tubes are in the pump nozzle. If they fell out, or broke... then you will pump water in, rather than suck it out.

 

[Apeman]

Good news I suppose. One of the welch plugs has a hole dead center, and it looks like the previous owner attempted repair with JB weld. What are the odds that the leak would springs immediately after I rebuilt the jet Pump?? Looks like I also have only one original stud holding the pipe to the exhaust manifold. Previous owner strikes again...
Currently the hole is roughly 1/8 to 3/16 inch, irregular diameter.
New and additional questions:
1. The proper repair, as I understand it, is:
a. pull the tuned pipe.
b. grind off the old plugs.
c. take it to a welding shop, with new welch discs, and have them welded on. (aluminum, tig, yes?)
(If I got any of the above incorrect please correct me)
2. To get me through the summer, can I drill out, and repatch the patch job? (cheese whizz approach, but Summer is wasting away and the missus is already pissed)
3. When I have the plug replaced properly, should I have them all done?

Thanks mucho guys!!

 

[mikidymac]

So, yes the correct way is to get the replacement plugs from @racerxxx and have them welded. A local shop might be able to do it quickly. I typically only do the two lowest plugs as those are the ones that go if fresh water. On a salt boat do all 4.

But.... to get you through summer get a new gasket, new stud and bolts with the correct thick washers and a skick of the JB weld putty. Grind back the paine to clean rough metal and put on the JB Weld Steel Stick and it should get you through summer. Put the gasket on dry and torque to factory specs.

 

[Apeman]

Hey Midi, two guesses how the JB weld patch, over an old JB weld patch went.
So, the pipe is out, the plug ground off, and I'm waiting for studs, gasket, and discs.
I'm actually relieved. I'd have been constantly worrying about when the patch would pop if it had held.
Boating is supposed to help relieve stress, not build it up.
You know, now that I see how much easier it is to do engine work in these boats versus skis, maybe a top end would be an idea for this fall.

 

[Apeman]

I regards to the condition of the Exhaust Manifold's bolt holes, I have a question:
How the hell do people strip these bolt holes? The two outside holes had been stripped, drilled, and tapped (poorly) to a larger bolt, coarse thread. They also used non SS bolts and snapped one off during reinstallation due to a poor tapping job. The stud was banged up a bit but OK. The inside bolt hole has been stripped and then I think they filled it with JB weld, and then reinstalled the bolt. How the heck are they stripping these holes??? I'm no master mechanic, but I can tell immediately when I've started a both cross-threaded. I just back off, realign and re-thread, repeat, till I have it right. Grrr....

 

[Dr Honda]

It's kind of normal on a poorly maintained ski. The hole will rot, and the threads get soft. Then, when they have a leaky exhaust, the automatic response is to tighten the piss out of the bolts, instead of properly fixing the issue. Then when it gets hot... the parts expand, and rip the threads out.

Depending on how bad the parts are... I've drilled to make a clean hole... tapped to a much larger size... filled the hole with Marinetex (a super strong resin) then drilled and tapped to the proper size. If done right... the repair will last the life of the ski. The other way is to install a thread saver/heilicoil. (just make sure to use a stainless coil)

Assuming bolt holes are good... the proper way to fix a leaky exhaust is to replace all the gaskets, bolts, and lock washers, and to torque properly. The torque on the exhaust bolts is only 18 Lb/ft. The spark plugs are tighter. Here's the deal...............

The exhust gets hot, and the parts expand. Then, when it cools... they all contract again. RIGHT? OK... so they are always moving. And because of that... you need a "Spring" in the system. That spring comes from good, properly torqued stainless bolts. When they are excessively old, and been reused a bunch of times... they work harden, and loos their spring. SO... when the parts get hot... they stretch past their spring point, and don't maintain pressure on the gasket. In turn... it leaks again. Along with that... an old gasket is hard, and won't seal. And finally... even new bolts... when over torqued, will get over stretched after a couple heat cycles... and you get a leak, again. At this point.. people think... "It has to be tighter", and casue damage.

So the moral of the story is... do it right, and things work, and last.

Oh... I know the book says what sealant and glues to use... but I personally use a heavy shot of copper spray on PWC exhaust parts to stick them in place. (it's an old-school head gasket sealer, but takes the heat of an exhaust well)

 

[Apeman]

Wow, now that's an answer! Thank you for the how, the why, and the what! I thought that SS bolts and fasteners were used solely for their resistance to corrosion. Never would have guessed regarding the ductility factor.
BTW, I have the copper based gasket sealer paste that I usually use for exhaust joints, and use only a very thin coat. Hope that's OK. It's how I did the previous three engine rebuilds and all seem to be holding well.
Thanks again,
-andy-

 

[Dr Honda]

Sure... the brush on stuff always goes on thicker than the spray. But it works the same.

 

[Apeman]

Thanks again sir!