92 Mercury 25hp 2Stroke will not start

[Jb1134]

First time boat owner coming from several years of kayak fishing. I finally convinced the wife to sign my permission slip on a small boat. I found a great deal on a small 1648 Jon Boat. A friend gave me his 1992 Mercury 25hp that was used on a Gheenoe but later swapped for a 9.9hp. When he stored the outboard he ran the motor with the fuel line disconnected until dry.

This week I finally was able to pick it up from him and mount it. After spending an hour trying to start it, I took it to my friends house the following day. My buddy and I were able to remove the carb and thoroughly clean it although it was not gummed up or any type of debris in the carb. We pulled the plugs, found a good spark but cleaned them and lightly sanded the electrodes anyhow. They appeared to be gapped properly and put off a bright blue spark when grounded to the block. There are two kill switches on this motor, one on the tiller handle and the other on the back of the outboard. The tiller handle was disconnected when I initially opened the cowling. We tried swapping from both kill switches to just one or the other. Still no dice. We also used a little starter fluid into the carb but would not crank.

Is there anything that I should check into?

 

[timguy]

Can you test the spark with a good tester? Indicated spark by just using a spark plug is often not good enough. Why? Under compression, with vapors in the cylinder, spark plugs act differently and often are not producing adequate spark for ignition. Please check to see that you get a spark with a good strong 7/16" arc, blue/white, "lightning like". You then, if substantial spark is observed, might want to do a compression test. This motor should run around 120 psi. If this all checks out, a new set of plugs is usually a pretty good idea at the start of every years boating.

 

[Jb1134]

Can you test the spark with a good tester? Indicated spark by just using a spark plug is often not good enough. Why? Under compression, with vapors in the cylinder, spark plugs act differently and often are not producing adequate spark for ignition. Please check to see that you get a spark with a good strong 7/16" arc, blue/white, "lightning like". You then, if substantial spark is observed, might want to do a compression test. This motor should run around 120 psi. If this all checks out, a new set of plugs is usually a pretty good idea at the start of every years boating.

Tim,

Thanks for the reply! No I haven’t tested it that way. I’ll have to get my hands on a set and give it a shot. I’ve got a friend coming by tomorrow to do a compression check on the motor with his gauges. Would the kill switch completely shut down any spark? Thanks!