This summer my father-in-law gave me his Troy-Bilt Super Tomahawk to use since he hasn't used it in a number of years. I had borrowed it probably 4-5 years ago and had no problems with it and he thinks that might have been the last it was used. I did some basic maintenance - drained and re-filled gas, changed plug, oil, etc. Ran a little rough the first time out, but smoothed out with 5-10 minutes.

The flail edges were worn so I got a spacer kit and replaced the spacers and flipped the flails to a good edge (looks as though they never were rotated before). I ran it a few times in August/September shredding/chipping some left over leaves from last year and some light brush from trees. I use it maybe 1-2 hours max at a time. I had no issues, seemed to run OK.

Engine is an 8HP B/S Model-190412, Type 3020-01, Code-88082910.

After using it a few weeks ago, I saw some debris under the top shroud (just covers the top of the head). I thought maybe I should clean out under there. I started loosening a few of those bolts and realized those are probably head bolts. I stopped and re-tightened and left it.

I went back to use it the following weekend and it seemed a little harder to start maybe and when I tried to engage the chipper flywheel I stalled it. I've learned how to engage without stalling, so that raised a flag. Started over and got the engine started and chipper flywheel running. Used it for maybe 20-30 minutes OK and then it started to lose power. An easy load of leaves in the hopper would slow it down and almost kill the engine. Obviously something was up so I shut it down and brought it back to garage.

After letting it cool down, I found that the spark plug was very loose in the head. I thought OK maybe that was it. Actually replaced the plug and tightened it back up. For a weekend or two, seemed to run OK. In fact, seemed to run very well the first time after installing the new plug.

Today though, after maybe 30-45 minutes, I lost power again. If I run it at about 1/2 choke, it seems to run Ok, not great, but it won't bog down when shredding or chipping. Again, obviously something wrong, so I shut it down and back to garage again (things heavy to keep dragging it back to garage!!).

I check the plug and it was tight in the head - so that didn't happen again. I decided to check on the debris under the top shroud by pulling off the front shroud (part with the recoil starter). I found a fair amount of debris - primarily what looks like a mice operation. Fins on the head were minimally blocked, left side of the cylinder looking from the recoil starter side was pretty much clear, but the right side was probably 75% blocked (or maybe more).

I've got a number of things going on, so I'm not sure where I should start. I cleaned out the debris, but I haven't gone any further. The problems seem to have begun when I loosened up a few head bolts and re-tightened. Even though the I probably had some cooling issues with the some the fins blocked, it seemed to have run OK even with that.

I was thinking maybe I should pull the head, clean it, replace the head gasket and start from scratch with clean cooling fins. But maybe that is not the problem or have I done permanent damage with a combination of loosening some of head bolts (I re-tightened but didn't torque them)and the probably 50% overall blocking to air cooling. I kind of doubt that just cleaning the fins will solve the problem, but maybe the uneven heating/cooling is my biggest issue. Does seem to run OK for a while after starting it cold, at least 30 minutes - hopefully that is a good sign.

Thanks in advance for anyone with some advice on where to start. After I rotated the flails, it was running great - really a nice unit, great job at both shredding and chipping.