The Bathtub - Engine

The engine is an old two-cycle Kohler K295-1T. From the serial number I would estimate it's a 1971 but Kohler sold off its two-cycle division a long time ago and disavowed all knowledge of the engines. Research suggests it was, like the Hurricane's Chapparral, used primarily in snowmobiles. Displacement is 295cc, producing a staggering 20HP. Okay, not exactly staggering but not hateful either for an engine this size. The two-cycle technology cut down on weight and prevented oil starvation due to its mounted angle. The mixture is an oily 20:1 which, given the advancements in oil technology, can likely be thinned a bit into something more manageable.

Though the engine turned over by hand and recoil, the whole thing was dirty and in need of a wash. The worst of it was cleaned off and a few experimental pulls were given, not really thinking it would start. I was not disappointed. Neither was I disappointed when the recoil decided break after a half-dozen pulls. So, time to remove the recoil assembly and see what I could see. A few empty mud dauber nests cleaned out and I found a broken recoil spring. Hmmm. Now, where to source parts?

For the recoil spring, I don't exactly remember where I got the information but I ordered in a Rotax recoil spring off eBay which seemed to fit the bill. After a few minutes to install it and new rope (because, I mean, who doesn't need new rope?) it was ready to go back on. Surprisingly, the mounting bolts seemed to have grown taller at some point and my new recoil couldn't even pull over to recoil. I'm embarrassed to admit how long it took me to figure that out. I still don't know what happened as I had numbered the bolts and put them back in the same holes. Strangeness.

Once the dust and cursing had settled, it was time to start the engine. I said, start the.... Oh, nevermind. I had rigged up a fuel tank from an iced tea container and fuel lines. Nothing was being pulled into the carburetor and it wasn't going to start no matter how many times pulled at it. Taking off the spark arrestor and giving a quick sniff indicated that special cologne reserved for varnished carburetors. Some spray lube squirted through the carb would get it going until it burned off so at least I knew spark and compression were there. Removal of the carb "required" I buy a set of crowfoot wrenches to remove the ancient Tillotson from the engine.

Unlike my prior experience with the Hurricane, this carb was able to be identified. Tillotson is still in business and parts are still made. Most of the fourms I stumbled into showed mixed opinions of the HR-78A but I took heart I could heal this one. Besides, I didn't have the funds to go out and buy a new carb like on the Hurricane. Without even opening the carb, an order was put in for a new gasket kit. In retrospect, it probably would have been a but smarter to wait but things worked out in the end. So, off to the races.

Disassembly showed pretty much what I would have expected for something stored outside for so long. The gaskets were shot and the diaphragms were wibbly, never mind the amount of gunk in the actual metal passages. The good thing about this carb and its age is the passages are huge compared to some others and it was relatively easy to get all the important parts cleaned. After a few days, the new kit arrived with new needles and everything was reassembled and installed. In the interim, I had managed to find some information about where to set the high and low needles and crossed my fingers I had gotten it correct.

Using my makeshift fuel tank again, I hooked up everything and set to pulling. Now, instead of nothing happening, I could watch the fuel beginning to be pulled, only for it to retreat halfway. After a stupid number of pulls with no love I decided to cheat. Using the afore mentioned spray lube, I pulled the rope and got the engine started then used the spary to keep the engine running long enough to prime itself. Turns out, this solution worked.

For the first time in who knows how long, the vintage Kohler was running under its own power. Maybe not well, but running nonetheless. So, pulling out my trusty screwdriver to make adjustments to the needles I decided I wanted to keep my hands more than a few inches away from a fan spinning at 3,600 RPM. Letting the engine shut off, I made a few adjustments and was pleased to see the fuel hadn't drained away. Again, I started the engine and everything seemed to be working fine...until the screwdriver I had used to make adjustments decided to shimmy its way down the cowling and into the propeller. Yeah, that just happened. Picking up my screwdriver from where it flew thirty feet away, I took a closer look at the damage and sighed. I had only broken one of the blades which, on this model, there are eight, all independent. Muttering...things to myself, I removed the broken pieces and the blade opposite so balance wouldn't be affected. So now, instead of a round prop, I have a bow tie.

The next few starts came and went with much less fanfare and I eventually got the engine dialed into where I wanted it (so I thought). Suffice to say, there are some things which are going to need adjusted now that I've been away from it for a short while and it may end up the Tillotson gets scrapped anyway. Still, I have a couple things up my sleeve to try. Until then, enjoy the sounds of a 197? Kohler K295-1T engine with a Tilloston HR-78A carburetor turning a six-blade bow tie propeller in a nearly fifty year old hovercraft.

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