hey
i have a lower unit from a 225 yamaha that has a crack in the housing in the exhaust tunnel,can this be welded if yes what kind off welding rods should i use ? material type?

I would tig weld if I was going to do it, you can control your heat better and it will look much nicer

Be careful gear lube could catch fire

I would not use the aluminum arc rod on that. It burns very hot and is kinda uncontrollable when welding something thin like that. Better off with a tig in this case...

I am a skilled trades tool & die welder for GM. If you need to ask what type of rod to use...you should not be attempting this. Take my advice sir, you can and probably will, do alot more damage to the unit. This will then double the cost to have it done correctly. Please have a knowledgeable welder look at it for you. Over the years, I have had many items brought to me that someone "attempted" to repair. In almost every case, they made the object wayyyyy worse than it was to begin with. Be smart...and know your limitations.

Even with a tig, you're going to put a lot of heat into this and the whole casting will twist. Maybe not perceptable, but enough to throw off machining tolerances. I'd seek out a new/used lower unit

thanks for the reply´s
i have a friend who is a tig welder who will do the job,but since i am not native english speaker i don´t know the tech name of the alu alloy ? that he should weld it with ?
do you have some kind of specs?
thanks again

Almost looks like its been "fixed" before. Alot of pinholes in the paint....

I do and have done alot of aluminum welding in my time. You must take out the internals first, bead blast not sand blast all the paint off a least 6 inches around the crack, it will be alot bigger then its showing also, then the outdrives are a poured casting and they are full of pits and holes, very pour castings all the time hard to weld and look good. pre heat is a key to stop warping also. It can be done but only tig!!! dan my 2 pennys

This is easier, has a warranty, and more reliable than welding that..........

http://www.sterndrive.cc/mm5/merchan...amahaLowerUnit