Test tank for jet drive?

[nslsubject]

I have a 1993 Evinrude 90hp jet drive on my 16' jon boat. Is there a jet drive version of muffs available? If not, and I have to use a tank, is there some clever way to keep the engine from emptying the tank in about 5 seconds? Would it work just to put it in reverse so the deflector is in place?

Thanks in advance

 

[Chief101]

Re: Test tank for jet drive?

If what you have is an Outboard Jet drive on an outboard than you would need to purchase a fitting that screws into the jet outdrive and hooks into a garden type hose fitting. I don't think that a tank is going to work well as you say it will empty quickly. Where I live outboard jets are common so the obj water fitting is common. Chief Chief

 

[nslsubject]

Re: Test tank for jet drive?

Thank you Chief, love your avatar.

I do have an outboard motor with an outboard jet drive. At least I think I do. I am not sure what my other choices are. There doesn't seem to be any obvious place to screw a fitting into. Is it something you would have to drill and tap? Or unscrew some existing fitting? Where would I find ao o.b.j. water fitting?

Thanks again

 

[dajohnson53]

Re: Test tank for jet drive?

Thank you Chief, love your avatar.

I do have an outboard motor with an outboard jet drive. At least I think I do. I am not sure what my other choices are. There doesn't seem to be any obvious place to screw a fitting into. Is it something you would have to drill and tap? Or unscrew some existing fitting? Where would I find ao o.b.j. water fitting?

Thanks again

THe only company I know of that manufactures the jet units for outboards is Outboard Jet Company and I'm pretty sure that would be what you have. They do aftermarket units (usually painted red) as well as OEM units for the major manufacturers (same units, but painted to match engines).

Newer outboard jets have a hose fitting on the port side right near the grease fitting. It is a stainless steel bolt, which you remove for a special (but commonly available) hose adapter. It is the same threading that is used for other screw in hose flush fittings that are found on some outboards.

If yours doesn't have that, you can get instructions from Outboard Jet Company on how to drill and tap one. You can also get an owner's and service type manual (really, just printed instructions) for your unit.

go to outboardjets.com for info, FAQ's and contact email and phone numbers. I've contacted them a couple of times and their customer service is excellent. With the printed material they sent me, I can now do complete maintenance, including adjusting and sharpening the impeller.

If you find that fitting right near the grease fitting, and can't figure out how to use it, contact me and I can help. I run mine on the hose all the time.

With my old engine (early 80s rebuilt V6), I couldn't run it for very long on the hose, it would over heat. Just long enough to winterize really. My mechanic said that it is probably just a matter of not enough water supply for the large engine. With a jet, a lot of the water goes out through the jet impeller (it has to be wet too) and therefore less is available to circulate through the cooling water pump. I don't know how it will work on a smaller engine, I imagine it would work better.

I am currently putting a newer, better condition V6 on my boat with the same jet unit, in a few days I will be able to run it on the hose and see if it has the same overheating issue that the old one had.

As for a tank, it would have to be a very large and/or long tank because of the force and volume that is pumped, even in neutral. I have not heard of any substitute for putting it in the lake/river.

PS: I painted mine to match my Johnson white and it still looks very good after 4 seasons. If you're interested, I can give you my method (really, just careful prep and painting of aluminum).

 

[nslsubject]

Re: Test tank for jet drive?

Thank you for the detailed info dajohnson53. The jet drive unit was factory installed, I believe. At least that's what the previous owner told me. The jet unit is matte black, there is no indication of 90hp on the outside of the engine but there is 65hp decal that looks official. At any rate, I'll look when I go home tonight but working from memory I don't think there is an existing hose fitting. I will check with Outboard Jet Company. I have been wondering about the details for dressing the impellor edge, adjusting the shims for wear, tolerance between the impellor edge and housing, etc.

I am happy with the black color on my jet drive (which matches my Evinrude) but I am interested in painting aluminum and am not sure just how to go about it. I have an old Grumman aluminum from my childhood that used to be green but is mostly aluminum color now. It'd be great if you'd let me know what you did.

Thanks

 

[dajohnson53]

Re: Test tank for jet drive?

If the jet matches the engine, it's very likely factory installed. And a 90 hp being labeled as a 65 as a jet is what they would do. I

Dressing and adjusting the impeller is very easy with the instructions they give.

Using a piece of thin metal the correct thickness (measured with a micrometer I have), I made a long feeler gauge to accurately test the clearance between the impeller and the housing. My mechanic says he just eyeballs it. This is a "fine tune" adjustment (in my opinion) and I've never seen a significant loss in performance from one year to the next even if I don't get around to adjusting the shims.

I'm not an expert in painting aluminum, but what I did on my jet unit has held up very well with no flaking or such. Even though it was already painted (maybe powder coated?), I sanded it completely with 3M abrasive pads. Not to remove the paint, but to roughen it up. I then cleaned very thoroughly with chemical cleaner I bought at an auto paint store. I then primed the whole thing, even the parts with solid factory paint still in place. I used the appropriate aluminum primer (can't remember the type, but it is for aluminum and is green). I did a couple-three of primer coats. I then did several thin coats of final paint (used Johnson white paint) according to directions on can. I didn't bother sanding between coats or clear coating afterwards because as you know, the paint job on the jet unit get's a lot of abuse, therefore a super fine hand rubbed finish is wasted.

I'll bet if you search on line you'll find a lot of folks who have painted aluminum canoes. I painted my Gruman back in the 70s when my brother and I duck hunted with it. It's changed hands a few times since then, but I know the guy who currently owns it, and the paint is still in good shape, just rubbed off from normal wear and tear, not because it's failing. We used some sort of etching chemical (IIRC it was a gel-like stuff we brushed on before painting). But it's been 35 years, so I have no idea what we really did!