Ted Williams 1972 7.5 HP Question/Problem

[allaboutheu22]

i have a 7.5 sears outboard motor which is do believe was manufactured somewhere in the early 1970's. the motor has been sitting in my dad's basement for about 15-20 years and i have recently had brought it up and tried to start it. It started and idled fine, but it didnt sound right. the engine breaks up at full throttle and does not run smoothly, i changed the spark plug. if it ran long enough, the plug would get fouled up and the motor would not start at all. i have come to the conclusion that this motor is not able recieve its maximum speed when at full throttle. i have tried to clean out the carbueretor and numerous other things but nothing has seemed to work out. i would appreciate it if anyone would have any ideas on what is wrong with this motor. any ideas?

 

[big dreamer racing]

Re: Ted Williams 1972 7.5 HP Question/Problem

Maybe the points are corroded/defective someway, try Filing them with fine course sandpaper then reset the gap, maybe the rubbing block is worn out for opening the points, also is it getting enough fuel try a little enrichment with propane for a moment during the breaking up time. Mine was a mcculloch engine. I had one maybe a little newer, worked great till the fuel pump quit doing it's job.

 

[allaboutheu22]

Re: Ted Williams 1972 7.5 HP Question/Problem

thanks but im not really sure how to get to the points.

 

[wizzy214]

Re: Ted Williams 1972 7.5 HP Question/Problem

whats your mix ratio? it sounds like its running rich and not wanting to run at WOT.

 

[allaboutheu22]

Re: Ted Williams 1972 7.5 HP Question/Problem

my mix ratio is 24:1...what do you think the mix ratio should be? 25:1?

 

[esemilio]

Re: Ted Williams 1972 7.5 HP Question/Problem

I had a somewhat similar peoblem with a two-cycle engine on a lawn mower. Engine would not run at fullspeed, not much power, and spark plug fouled with carbon deposits. After much trouble shooting, I found out that the exhaust holes were almost completely shut with carbon deposits (previous owner used too rich oil/gas mixture?). After opening exhaust holes, engine ran like a champ! Hope this helps.