125 hydro dragster
Posted: Wed Mar 16, 2011 11:10 pm
Hi all. Just found this site and have been enjoying combing through the old posts. Lots of good info and interesting builds. I am currently working on a 125 project that has become a dragster instead of the parade only tractor it set out to be. The history on this actually goes back to a 125 my dad had since I was about 9 yrs old. By the time I was 12 I was mowing with it, but by the time I was 17 that job fell to the neighbor kid as I was working in my dad's garage. Well the little Kohler developed an oil leak which the kid didn't notice and it didn't take long for the 30 yr old engine to lock up. A replacement engine was hard to come by used and too expensive new. As we lived in Maine it occurred to me that there were lots of horizontal shaft engines to be had cheap...snowmobile engines. So we scored a 440 Rotax for $100 and I grafted it in. It was pretty easy and the hydro doesn't care where your engine makes its power just keep your revs up and modulate hydro input. So we went from 1 cyl to 2, cast iron to aluminum, 4 stroke to 2 stroke, tired 12 horse to tired 30ish? (guessing on that last one) It worked out ok, but drove my dad nuts because he kept trying to lug the engine like it was still a 4 stroke and consequently fouled the plugs pretty fast. I actually mowed the lawn with it a couple times without a problem (the neighbor kid didn't work out) and it would pull a wicked wheelie. After I went off to college dad just hired someone else to cut the grass with their own mower and it didn't get used any more. I got married and moved down to Florida, Dad sold off the garage and let the 125 go with the property. Well, when I heard that I got all indignant that he would let my creation go so easily and decided I needed to build something similar. I had scored a military surplus 4a084 opposed 4 air cooled 84 ci engine off ebay earlier intended for an unrealized generator project . (apparently any generator I build needs another generator as a backup just in case mine doesn't work when needed, according to my wife....you know, a backup for the backup. So I just cut to the chase and bought a "real" generator) I found a 125 locally for $200 and decided to put the two together. It was just supposed to be a fun parade-type tractor but I recently found out that a local dragstrip has lawn tractor drags twice a year and I couldn't resist. So the plan changes slightly and I start looking for more top end. Sorry for the long post. I'll let the pics take it from here.