Well after finally getting a chance to really put the Bush Hog HD-12 to some hard labor I was able to see how it would do. Overall it does great and I like running it. It does a great job plowing as long as I don't lay in to the hydro pedal too far.
When I first noticed it was when we did the tug of war at plow day. I ended up stalling the motor because I tried going full bore with the pedal. If I go more than half way it starts to kill the engine. I just can't tell if it is because the engine doesn't have enough muscle or if there might be some sort of issue with the hydro creating too much pressure. I would think the tires would spin before killing the engine.
The tug of war was on Friday and Saturday when we were plowing I only made one round because I wanted to shoot as much video as possible. I wanted to see if it would do the same thing while plowing and sure enough it did. I can plow with the engine at idle, 1/4 throttle, full throttle or anywhere in between but even at full throttle as soon as I try to go past 1/2 to 3/4 pedal with it pulling it wants to kill the engine.
Alan and I were talked later Saturday and he mentioned the points gap which during our discussion I realized I never checked it. So today I took some time and checked the points gap and it was off a little bit. It was too tight on the gap. Manual calls for .023 and I would say it was around .010. So I re-gapped the points. The other thing I did was I only had the governor spring on the 4th hole and I moved it to the 7th hole on the governor arm.
Took the HD-12 for a drive around the yard and the one smaller hill I tested it on. I had it at full throttle and about 1/4 pedal starting up the hill and tried giving it full pedal about mid way up and it wanted to bog down and die. If I am running on the flat or light load it will run with full pedal travel even at idle.
I am guessing that the hydro unit might need rebuilt or replaced or the engine just doesn't have enough snot to it.