Omc 25h.p.

**JohnsonM50** · 07-09-2006

If when I get into the sacrificial omc foot I find that the yamato foot studs make it impossible to save the omc pump then that will have to be Plan B. Im not going to alter the Y foot, and a local pal told me he electric pumped a race lower and cooked a motor anyway. My hydro cockpits small to me at 195lb so Id rather keep it as simple as possible,, throttle, wheel & killswitch.
I think it has the potential of being pretty fast anyway though.

**JohnsonM50** · 07-20-2006

Ive mulling over how to do this gearfoot morph. The 102 foot studs clear the OMC water pump the rear 1s easy, the front 1 is close to the limit of still being in the case once drilled. The exhuast/water pick up is close to the prop area so will need to be moved back. Ill need to make an adapter plate to 2nd as a replacement anticav plate. Its alot of work but if you like that kind of thing its fun.
The biggest obstacle is aluminum welding, Im going to try an aluminum brazing system on some minor stuff to see how it does. Otherwise I can get welding done at about $30.00 an inch and a re-diculous wait time and I always do my own prep and jig work. Has anyone had any experience with these type welds? Ive got lots of braz and steel gas weld time from the autobody days, some arc too but a different brand of stuff I tried was very challenging.
I took my airborne to Lk Wallenpaupac Pa last weekend and found out you cant run altered exhaust in Pa. At least they didnt get me till I was leaving. Thats the 1st thing Im going to try the weld stuff on to divert the sound down [Id really like to figure out how to make my midsection into a tuned exhaust thats reasonably quiet]. Oh, the Ranger didnt write me up, he acknowledged that I was driving responsibly and he liked my pals and my boats.

**Roy Hodges** · 07-20-2006

Suggestion ; i am a welder. I suggest you try and find a welder who does sheetmetal welding 40 hours a week. especially one who speciallizes in aluminum & stainless . (you don't need the stainless , but that guy will have the savvy ) and that guy can be fast. & that means more economical. or should, anyway. If he has a mig machine with a spool gun ,he can do it so fast , it'd make your head spin. it would behoove YOU to prep it first , just before welding . that means wire brush it w/a Stainless steel wire brush, then wipe it sterile with a rag saturated with acetone . nothing else . a cleaning is only good for 24 hours before welding. Aluminum is NOT like welding steel. Don't let anybody tell you it is . Cleanliness is next to godliness ! I hope this can help some of you .

**JohnsonM50** · 07-21-2006

Thanks Roy I have access to a mig welder and have found it not too hard to weld steel, judging around the end takes getting used to compared to arc. Id guess aluminum is harder or everybody would be doin it.

**JohnsonM50** · 07-29-2006

Originally Posted by JohnsonM50

Ive mulling over how to do this gearfoot morph. The 102 foot studs clear the OMC water pump the rear 1s easy, the front 1 is close to the limit of still being in the case once drilled. The exhuast/water pick up is close to the prop area so will need to be moved back. Ill need to make an adapter plate to 2nd as a replacement anticav plate. Its alot of work but if you like that kind of thing its fun.
The biggest obstacle is aluminum welding, Im going to try an aluminum brazing system on some minor stuff to see how it does. Otherwise I can get welding done at about $30.00 an inch and a re-diculous wait time and I always do my own prep and jig work. Has anyone had any experience with these type welds? Ive got lots of braz and steel gas weld time from the autobody days, some arc too but a different brand of stuff I tried was very challenging.
I took my airborne to Lk Wallenpaupac Pa last weekend and found out you cant run altered exhaust in Pa. At least they didnt get me till I was leaving. Thats the 1st thing Im going to try the weld stuff on to divert the sound down [Id really like to figure out how to make my midsection into a tuned exhaust thats reasonably quiet]. Oh, the Ranger didnt write me up, he acknowledged that I was driving responsibly and he liked my pals and my boats.

I tried the aluminum brazing rods on my above the water line exhaust, I angled it down at about 45 deg. to tame the noise. The weld so far held up to about 50 mph / 50 mi. so Im happy with it. Sort of difficult but w/ practice who knows. Acetylene / oxygen would be the way to go cause map and propane take a long time to heat and thick to thin welds are harder yet.

**Skoontz** · 07-29-2006

The only way to weld aluminum in my opinion is Heli-Arc. I've seen other ways work in a pinch but I feel Heli-arc will get the most penetration and control over a non ferous metal. But hey, if what you did werks, does that not say it all????

**Roy Hodges** · 07-29-2006

It depends on the thickness of the allow. mig alum. with a SPOOL gun is the way to go, if the alum is at least about 1/8th " or thicker . I know , most of you don't know what a spool gun is . ask any real pro welder .If conditions are favorable , you have to see it , to believe how good and how fast it goes . it can weld aluminum faster than steel can be welded. I KNOW what i am talking about . P S ; penetration is way OVERRATED . in a properly welded weldment, you don't need a lot of penetration, too deep is actually contra indicated , and can actually weaken the joint .

**Skoontz** · 07-29-2006

Good knowledge Roy...Never even thought to use a mig spool but I'll try it on a few scrap hunks and see what/how I do. Too many years welding moly cages and buggy bars I guess.

**JohnsonM50** · 07-29-2006

I just did some more brazing on the omc gearfoot, a filler to drill the rear stud thru. Acetone seemed to improve the tinning step, it brushed out instantly. The foot is cast, varied thickness and the filler is 3/8 thick it seemed to take well.