Welding mating surface on Yamaha powerhead

[rpambrun]

Has anyone in the Wilmington, NC area had any experience having some welding done on their powerhead to resurface the mating surfaces? I discovered that I had just enough corrosion around one side of the exhaust port on my powerhead to allow gasses to escape and allow water to run in to the exhaust tube.

[TownsendsFJR1300]

Glad you finally found the leak.

If you can't find any reputable welders, try a prop shop. They weld aluminum props to like new...

How long is the corrosion?

[rpambrun]

The corrosion was not too bad, just enough to make a leak. This picture shows the line I made with a sharpie, but the corrosion was mostly on the curved part. I took a file and whittled it down to bare metal. I'll call around to the prop shops tomorrow. I got one possibility at a machine shop here locally/

[Keith Ohanesian]

Call Warren Racing Engines in Clinton 9105926724. If they can't do it they should know who can.

[rpambrun]

Call Warren Racing Engines in Clinton 9105926724. If they can't do it they should know who can.

I took a drive out Clinton to see these folks. After about a half hour of deliberating and looking at the power head, they said they would not be able to clamp the PH to mill it, so back to the drawing board and still looking

[TownsendsFJR1300]

A mill would be real nice but as noted, ain't gonna happen...

Way back, I had a Yamaha MC engine with 1 of 4 main studs that hold the cylinder and head on, strip out and the edge of the block crack (1970 ATI 125cc).

We had the block / hole welded back up. (I was 15 or 16 at the time) and I spent many days with a file and flat edge filing and drilling/threading.
I suspect you'll be doing the same.

At least now a days, there's more tools to work with, dremels, etc.

Worked great after that, no leaks (no sealer either) and that sealed the lower end of the two stroke which has fuel/air being pushed thru it, (piston/port configuration)

[rpambrun]

A mill would be real nice but as noted, ain't gonna happen...

Way back, I had a Yamaha MC engine with 1 of 4 main studs that hold the cylinder and head on, strip out and the edge of the block crack (1970 ATI 125cc).

We had the block / hole welded back up. (I was 15 or 16 at the time) and I spent many days with a file and flat edge filing and drilling/threading.
I suspect you'll be doing the same.

At least now a days, there's more tools to work with, dremels, etc.

Worked great after that, no leaks (no sealer either) and that sealed the lower end of the two stroke which has fuel/air being pushed thru it, (piston/port configuration)

Well, I've got a few other irons in the fire, but I'm slowly moving to the fact that I will probably have to get a good file and a couple of good stones and do it myself.

[rpambrun]

I finally got to filing the power head down and it was not as hard as I had envisioned. The two pictures show the results. The only thing I am concerned about is that the welding was not as good as I had originally though and maybe the curved area of the exhaust port should have had a little more metal added to it. It may be OK, but I would like an opinion or two.

Thanks

[TownsendsFJR1300]

Short of a new block, looks really good! That won't leak like before.

Does Yamaha call for any sealer or just the gasket?

[TownsendsFJR1300]

If any doubt, NOW is the time to have the welder run a short bead in that area, but it looks good!

[rpambrun]

Short of a new block, looks really good! That won't leak like before.

Does Yamaha call for any sealer or just the gasket?

According to the SM, no sealer or gasket seal is used. I would think that the area on the gasket that surrounds the exhaust would be something more like exhaust gasket material, but there seems to be a sticky substance in that area. I have to pick up my new fuel tank Monday (when it rains, it pours) so I think I will have them put a bead around the thinner area. That shouldn't take long to get it leveled.

[TownsendsFJR1300]

If the gasket has some sort of sticky film in that area, I don't think I'd put additional sealer on it. That may hamper the sealing properties of the seal itself.

Any place, the gasket is just gasket material(no film) I would think some Yamabond won't hurt anything.

Anything (sealer) near where the exhaust is blowing out has to hold up to very high temps...As good as your block looks now, I think your fine without anything additional..

[rpambrun]

I went out to Gore Marina tp pick up my new tank and one of the brothers did some more welding on the PH. I filed it down and it does look a lot better than before I had them do that.

[TownsendsFJR1300]

Heck, your good to go!

Lots of wrenching, saved a bunch of $ too!!

[panasonic]

I went out to Gore Marina tp pick up my new tank and one of the brothers did some more welding on the PH. I filed it down and it does look a lot better than before I had them do that.

First thing you learn in machinist school is how to file....a lot of filing. Nice looking work, I hope it seals up good.