Sno Cat Repair

There isn't a lot of snow in the Big Horns, but enough that you need the Sno Cat to get in and out of the cabin. Dad brought it up a couple weeks ago, but right away it showed some problems. So we set out today to fix them.

This guy is trustworthy. But after 50+ years of service, anything is liable to breakdown. After the first trip into the cabin, Dad noticed the fuel pump leaking. It has shown some troubles before, so he just ordered a new one. After putting it on, the carburetor started leaking and the engine began to miss. So he brought the carburetor home, but found no real issues with it. 

Having a troubleshooting game plan, we headed up to Deer Haven where the cat is parked. Beyond beautiful day.

The engine is a simple flathead Chrysler. In general, it has always ran good for us. 

Our basic thought was that the new fuel pump was putting out too much pressure, overriding the float in the carburetor. We learned that this can be a scenario with new fuel pumps on old engines. This speculation was further confirmed by the liquid gasoline in the intake manifold. All fuel that comes through the carburetor should be gasified. 

The ultimate test was going to be through testing the actual fuel pressure. For this we got a low pressure fuel gage tester. 

So Dad held it tight on the line and I cranked it over good. There was at least 5 lbs of pressure, which is on the higher side but not off the charts. 

Wanting to lower the pressure, we installed a regulator that Dad had purchased. With the pressure gage, we were able to turn the pressure down to 3 lbs. 

Then put the carburetor back on and hooked everything back up. 

Ran like a champ with no leaks. 

So to make sure we had enough pressure for the job, we ran the cat into the cabin. 

It's always fun to cut new tracks. 

Looks like winter up here. 

No one has really spent any time up here yet.

So we cleared the deck and went in. 

It has been real warm, but up here it was about normal.

So we kicked up our feet and stayed awhile.

Good stuff. I'm thankful for old equipment. When it breaks down, it teaches you something about mechanics. There's always more to learn. Good way to close out 2025. It's been a fast and fun year. Now we're on to the next one!