Honda PA50II stutters at 20 mph

[otto-man]

I'm working on a 1980 Honda PA50II and can't seem to get it to run smooth at WOT. It starts and runs great up until about 15/20 mph, then stutters for a few seconds, clears up a little, then repeats. So far I've put in a new spark plug, new air filter, Fresh 25 to 1 gas, new gas line with inline filter, points looked good but cleaned and adjusted anyway, compression is at 120 psi. This thing is driving me nuts. Anybody have any input. Thanks.

[otto-man]

Finally got it! The air filter was WAAAAY to restricted. Honda no longer makes an air filter for a PA50, so I used one from a Spree. I cut it to fit and was still too dense. I sliced it in half and that was the cure. Runs great!