Bonneville America Forums Forums Technical Forums General Tech Safe-Start Epoxy

I think the "Safe-Start" idler boss reinforcement product is a great thing.

I do have a question though. Has anyone re-checked their Safe Start installation after, say a year or more?

Reason I ask is, I'm attempting something similar to repair a broken Shift Shaft lever boss on a '85 Kawasaki GPZ that has left a hole in the crankcase. Proper repair (replace lower crankcase) becomes a BIG hassle, because, for the GPZ, according to Kawasaki, you MUST replace BOTH crankcase halves, as they're machine matched.
I've engineered (BWAAA...) a slip-over and clipped reinforcement piece, that I want to "reinforce" with epoxy. There is no measurable tension forces on this piece, only shear. (so I think)
I intend to epoxy the broken piece to the crankcase, epoxy the slip-over washer to the piece and the surrounding crankcase surface, and epoxy the bolted clip that holds the washer against the piece.

I'd like to know if the epoxy holds up under the conditions surrounding the repair. (crankcase material, heat, oil, time, etc.).
IF it has, and I'm sure it has, I'd also appreciate the EXACT manufactures item info. (number?) of the JB Weld used, and the info. on what type "cleaner" was used for the crankcase surface. I believe the J. B. Weld mentioned in the Safe Start info. is available in a couple different mixes.(?)
I have Lacquer thinner, acetone, and alcohol at home.

1) THE HOLE

http://i422.photobucket.com/albums/pp309/Opissant/DSC_0006_zpskie4ual0.jpg

2) THE PIECE

http://i422.photobucket.com/albums/pp309/Opissant/DSC_0007_zpsozh8dze1.jpg

3) THE PIECE IN THE HOLE

http://i422.photobucket.com/albums/pp309/Opissant/DSC_0008_zpsenqjs6mv.jpg

4) THE SLIP OVER WASHER

http://i422.photobucket.com/albums/pp309/Opissant/DSC_0011_zpsvg7wufhs.jpg

5) THE BOLTED CLIP

http://i422.photobucket.com/albums/pp309/Opissant/DSC_0013_zpsowayolps.jpg

6) CLOSE-UP OF WASHER & CLIP INSTALLED

http://i422.photobucket.com/albums/pp309/Opissant/DSC_0015_zpstn2khv4i.jpg

7) COMPLETE (minus epoxy) WITH SHIFT SHAFT ASSEMBLY

http://i422.photobucket.com/albums/pp309/Opissant/DSC_0020_zps7hvjzity.jpg

You couldn't ask for a much better break in terms of being repairable. I would get that case as clean as possible and have a good tig welder weld that back on. If you epoxy it that may be a problem if you wanted to weld it later.

The best degreaser I have found is the prep solvent used prior to painting automobile surfaces. If you intend to weld it up, be aware that specially Aluminum castings must be preheated fairly hot prior to the weld procedure, only to be heated up much higher during the weld. You need to make sure you won't be cooking some adjacent seal beyond usability in the process. The strongest epoxy I have used to date is made by an outfit named Belzona and it's not cheap.

There is much less need to preheat with TIG, with MIG you need to get the object very hot first because you are basically arc welding the part. With TIG the heat comes from an arc but you use it more like a torch to create the puddle then add filler sort of like brazing or more so gas welding. With TIG you hold the heat on the object then add filler as needed where as with MIG the filler is what creates the arc and therefore the heat.

In my limited 10000 hours of arc time experience, i have found, it behooves both processes to preheat for good results. Aluminum sucks the heat from the puddle to the surrounding material due to the heat conductive properties of the metal. I do still hold a valid American Welding Society cert for Aluminum, all thicknesses, all positions, all alloys, x-ray clear, for both Mig and Tig procedures. Just in case you're wondering where I'm coming from.

Wasn't wondering since I was speaking from practical experience welding motorcycle engine cases.

Erle,
I believe you want JB 8265S which is the commonly known two tube package that every automotive store has. I've used it many times, exposed to heat and oil and it just won't fail. I clean with Dawn dish detergent, followed by acetone and then rough up the mating surfaces with some 600 grit, clean with acetone again then mix and apply. The ambient temperature of the materials and workspace make a difference, I've had difficulty with curing below 40° and above 90°. I've built up engine block bosses for valve covers and drilled and tapped it. Built up case bosses in an old 64 Triumph and used it to hold a Helicoil. None have failed. Just my 2¢.

That's what I'm interested in doing.

I BELIEVE I'd have to empty the cases to weld, due to the heat, proximity to other moving internal parts, seals, etc. Maybe not.

I do have an extra pair of cases, from the FIRST motor, that had a rod cap nut come loose, and bent the rod.
Due to the unavailability of aftermarket parts for the '84-'85 550 GPZ motors, the crank was sent to California to be checked to see IF it could be fixed, and it could, but the only fix was to "Spray-weld" the crank, and then turn it down to OEM spec. That was $500 alone. No aftermarket rods are available, so a used set would be required there, and the pistons/cylinders were scared to the point of needing replacement. The only aftermarket pistons are a Wiseco set (615 cc/$600), and a bore job. Gasket set's over $100.
The cost got high FAST.

We got a salvage yard motor ($490, including shipping), and after the install, while replacing seals after verifying it ran, exposed THIS!

For NOW, I want the cheap, easy fix. If I get a few thousand miles out of the motor, and it seems to become a keeper, I'll tear it down, do a full rebuild, and use the old cases for a proper repair.

Keep in mind, THIS motor ran and shifted great, and there was no indication of anything being wrong.
As you may picture in your mind, there seems to be no tension on the boss, and only a minor amount of shear forces/movement. The way the broken material is shaped, as long as it can be held in place, it shouldn't allow for sideways movement (picture snapping a wooden 1 x 2 in half, and then pushing the two broken ends back together. Kinda "locks-in", finger-joint style). Ay?
So I do believe this "epoxy" type fix, with the clip and washer, should work for a long, long time.

More importantly, IF there was a complete fail, it shouldn't have any dangerous consequences that could lock up the tranny going down the road. At most, it just wouldn't shift.

(I THINK)