HM100 won't start or throttle

[Eric]

I have an older Tecumseh HM100 in my sailboat that I recently bought. It seemed to be running fine (a little slow to start is all) until I added new gas to the tank about 10 days ago. That day it started running slow and then quit on me when I put into idle. Happened again the next day, and was even harder to start, when it would. Replaced the spark plug yesterday and was able to get it started right afterwards, but was not able to get started again today. When it started yesterday, adjusting the throttle had no effect while running. Noticed that the new plug tip was black after only running the engine for 5 minutes. Yesterday I cleaned the tip and was able to restart the engine a second time, but have not had luck since.

I am not an engine expert by any means, but want to try to solve this on my own. Any suggestions on where to start? Telling me I am in over my head and need to seek professional help is a valid answer... :-)

Thanks!

[Eric]

After several hours more playing with the engine, I got it to run (rather roughly) by doing some serious adjusting to the carburator. It still is not running well, but I am assuming that further adjustments to the carburator should fix that, at least to some degree. Any advice is still welcome.

[Wgoodrich]

Not sure the hm100 model. However if you have a high speed and low speed fuel adjustment try turning both the fuel adjustment screws in snug the back out 1 1/4 turns. That should be close. Then adjust a 1/4 turn at a time to get optimum power and speed.

Are you sure you have a 4 cycle engine or is it a 2 cycle engine needing oil mixed with teh gas?

Curious

Wg

[Eric]

It had better be a 4 cycle, since the previous owner never used a fuel-oil mixture!!! :) I am going to go down this weekend and play with it some more -- I'm pretty sure it is running too rich right now so I may just adjust it from there and see what happens.