Suzuki DT 140 cracked LU.

[TownsendsFJR1300]

Obviously, this is a Yamaha forum however I know at least Rodbolt has posted on other Suzuki forums. The issue could apply to Yamaha's as well..

My neighbor has a 1999 DT140 2 stroke with a very cracked LU housing(sorry no pic's).


Parts fisch, carrier is part #28;

http://www.boats.net/parts/search/Su...ION/parts.html

Apparently, its a regular issue with these engines, piss poor metallurgy.

There are actually two cracks, one on each side. From the aft edge forward, even with the output shaft, then downward. These cracks are in total about 5" each including the downward travel. Suzuki also secures the MAIN output shaft carrier to the LU with two bolts.

The unit was removed about 4 years ago, the output shaft carrier removed and the case welded (and ground down). It was NOT primed at the time. I suspect, corrosion started up again and actually split the LU casing.

Anyway, We went to a place that "fixes them" 2 hours from here and didn't end up leaving the unit there(long story)...

I have a local machine shop that does excellent aluminum welding/work and looking at the parts fisch, to remove the carrier doesn't appear to be difficult. BTW, the cracks are approx 5" AWAY from the main carrier o-ring (to case).

My neighbor went back to Colorado, so we're on hold for now. I suspect we'll pull the carrier, (already have the LU off) and have the welding shop look at it.

Question, does anyone know of a reputable welding shop (in Florida preferably) that deals with LU's and this issue?

Thanks

[robert graham]

Without photos it's hard to say for sure, but I'm thinking the cracks may/can be welded, but the problem may be machining the welded surfaces where the carrier seals/O-rings must contact for a tight seal....Maybe explore used lower units that could be installed more efficiently and economically than the weld/repair.

[TownsendsFJR1300]

Without photos it's hard to say for sure, but I'm thinking the cracks may/can be welded, but the problem may be machining the welded surfaces where the carrier seals/O-rings must contact for a tight seal....Maybe explore used lower units that could be installed more efficiently and economically than the weld/repair.

New lower units are extremly RARE. One was found overseas (just the housing for over $1,000. plus shipping to the states.

The main o-ring is about 5" from where any welding would be so we'd likely pull it apart just so, if anything, we can clean up and prime it once done.. We've been looking for LU's for 3 years.. To find one used in fresh water, would be the ticket..

I'll post some pic's eventually (the LU is in the rentors garage)..

[boscoe99]

This one seems to be available and for not a lot of money in the scheme of things.

55100-94510-02M SUZUKI CASE ASSY, GEAR (SILVER)

[TownsendsFJR1300]

This one seems to be available and for not a lot of money in the scheme of things.

55100-94510-02M SUZUKI CASE ASSY, GEAR (SILVER)

At least its here in the states. I'll forward to my neighbor.

Thanks Boscoe.

[robert graham]

$938 seems pretty fair....what kind of condition is the rest of his motor in?....I mean, is it worth a new $938 gear case?...

[TownsendsFJR1300]

$938 seems pretty fair....what kind of condition is the rest of his motor in?....I mean, is it worth a new $938 gear case?...

Its a pretty good shape for a 1999. Fuel injected, very, very dependable.

Its flushed after use and does run very good. I wouldn't hesitate taking it anywhere short of the LU.

The crack is in such an odd place, especially with the very large internal carrier....

He was looking at a new case overseas but shipping here was a small fortune alone.

He's the kind of guy that would NOT sell his boat as it is(even thou it does run as is).

The "mechanic" at the other shop we went to said "run it till it blows"! The lower unit shifts and works great, no issues whatsoever with the internals..

He ran out of time down here to bring it to the welding shop and get a "yea or nay" on welding the case.

If the shop says they can weld it, we'll pull the carrier out over here. Contemplating welding some additional pieces(1/8" aluminum) in the same area and buy some more time too..

[robert graham]

Heck, if the cracks are more cosmetic than structural and it's working fine as is, then seems like the aluminum welding, maybe add some metal, grinding, painting and run it some more. I had some aluminum welding(TIG) done last week on my rail buggy and it came out good, a bit pricey compared to regular steel welding, but still O.K....good luck!

[TownsendsFJR1300]

I agree. The place we went to is a "specialized shop" in this type of tear down / repair, put back together for Suzuki LU's. Real nice web ad.

We found out, once there, they worked out of a storage shed, no office, the guy couldn't gaurentee the unit wouldn't be sold before we could get back up there (WTH???).. (more of a marine junk yard)

Very shady...

The welding would be the cheapest, its just that whatever Suzuki used in their "aluminum mix" was crappy... Hopefully that won't be an issue once / if its under the TIG tip and heated....

[robert graham]

Maybe you need just a darn good TIG welder and not necessarily a "marine welder"....probably a good idea to add some metal with the welding to strengthen it and hopefully not have to do this again....I had some cracks welded up in my old Tanaka lower unit maybe 20 years ago and the welder built up a good bead on the outside and it's still fine to this day....a bead on the outside shouldn't slow you down much....good luck!

[TownsendsFJR1300]

Maybe you need just a darn good TIG welder and not necessarily a "marine welder"....probably a good idea to add some metal with the welding to strengthen it and hopefully not have to do this again....I had some cracks welded up in my old Tanaka lower unit maybe 20 years ago and the welder built up a good bead on the outside and it's still fine to this day....a bead on the outside shouldn't slow you down much....good luck!

Thanks Robert. I suspect that's how we'll proceed. I don't have a TIG welder but MIG and arc welders...

This company I'm looking at I have an account with, and they do excellent work...

[99yam40]

I had the block on my C40 welded and watched while they did it. High frequency tig machine.
had problems with gassing off as metal melted and blowing holes in weld. I cleaned all the corrosion I could with stiff wire brushes and he used a clean grinder to grind back down even before he started to weld and after, but kept happening.
If it is the metal they use or if the salt water and corrosion puts something into the metal as he claimed I do not know.
But he got the corrosion hole covered and I then filled in the crater from the inside of stat housing with marine JB weld and shaped it after curing.
working OK for now anyway

[TownsendsFJR1300]

I had the block on my C40 welded and watched while they did it. High frequency tig machine.
had problems with gassing off as metal melted and blowing holes in weld. I cleaned all the corrosion I could with stiff wire brushes and he used a clean grinder to grind back down even before he started to weld and after, but kept happening.
If it is the metal they use or if the salt water and corrosion puts something into the metal as he claimed I do not know.
But he got the corrosion hole covered and I then filled in the crater from the inside of stat housing with marine JB weld and shaped it after curing.
working OK for now anyway

Yep, that's what I'm afraid of. That housing is pretty thin to start with. I guess they count on the carrier to do most of the support.

I suspect the outer edge of the carrier is corroded, expanded and forced the actual LU to crack.

If successful with the weld, we'd clean everything (including the edge of the carrier) up spotless and prime to slow down the corrosion. I'd likely put a light layer of the Yamaha waterproof grease (that's used on the the middle of the main shaft/splines, really good stuff) on all those edges as well..

[99yam40]

I believe I have read they normally drill a hole at the tip of the crack before welding to stop it from going any farther.
But I always wonder how do you deal with the inside sealing surfaces after welding the outside.
But if the weld does not cross them you should be OK.


As always there is another but,
if the corrosion in there was that bad, what does the o ring sealing surfaces look like

[TownsendsFJR1300]

I believe I have read they normally drill a hole at the tip of the crack before welding to stop it from going any farther.
But I always wonder how do you deal with the inside sealing surfaces after welding the outside.
But if the weld does not cross them you should be OK.


As always there is another but,
if the corrosion in there was that bad, what does the o ring sealing surfaces look like

I worked in a machine shop when I was 19 and the boss/owner was literally brilliant. He could do some serious Tig welding, he just started teaching me before we moved. But back then, I did the prep work on the aluminum, cast iron (very difficult to weld), etc. Narrowed auto rear ends, made race axles from scratch, I made roll bars, disassembled 9' Fords, 12 bolts, 8 & 3/4 chrysler rear ends (for narrowing), a very neat job.

You are correct about drilling a hole at the end of the crack.

I already have it sanded down to bare metal so we know how long each one is.

The main carrier, large o-ring is MUCH deeper then the crack, probably 4-5" away. Oil/water intrusion isn't an issue. So there wouldn't be any grinding / welding near the sealing surface.

A "V" is usually ground down the lenth of the crack, almost thru. Your actually adding filler into that groove and hopefully getting good penetration to each side. Unfortunatly, this housing is very thin to start with. You definitly want it ground down to clean/bare aluminum. Any corrosion left in the work area is NOT good...

Any burn thru, would have to dremeled off so it doesn't catch that main carrier O-ring (which would be new anyway).

The lower unit isn't leaking at all so I'm not overly concerned about that. If we get the ok for welding, we'd break it down and inspect that sealing surface to make sure that's still good(should be)..