Welding up a Yamaha 2 Stroke Block

A Bud that builds Racing Outboards brought me this block. I saw it a few months ago and told him I thought I could fix it. My Bud blends this area to improve flow but this block was very thin from corrosion.

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Being Cast I need to use a filler that has a bit of Silicone in it, wets easily, and not prone to cracking. 4043 Alloy in 1/16th inch will melt fast, wet out well flowing over the damaged area, and remaining there forever.

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To ensure a positive flow of 4043 into the substrate I use my TIG machine set to 65 amps, 50/50 Argon Helium gas mixture set to 20cfm, 65% polarity (heavy cleaning), 75Hz Frequency, and instant on - no foot pedal ramp - instant 100% 65 amps. This lets me either burn off contamination or flow it. I took the pictures before going all the way around so you can see how I'm stitching a layer of good alloy over the damaged area a arc at a time. I pop it, fill it, and get off it within a second. Got to move fast or the damaged metal will fall out.

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Now this can't be blended down enough to match the flow of the other Ports but it can be placed into service for a "Daily Driver" so to speak saving a very expensive Engine Block. My Bud will do the dressing, he is a professional at that.

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Much more metal around the damage to support the repair.

I think your friend will be very pleased.