thompsondockside.com

I have a 1968 100hp Johnson on my 1967 21ft Thompson Offshore Camper. I have been working on this outboard for the past year and cannot seem to get her to run right. She has a sensor trigger. I put in a new wiring harness, pulse pack, stator, coil and rectifier. I get spark and she starts right up. She runs for about 15 minutes and then starts to sputter and deteriate. She then stalls and I can't get her to run again. No Spark at that point. Lost on what is causing her to shut down after the 15 minutes. Am I missing something? What can cause this? All suggestions are welcomed. Restored the boat, but cannot use becasue of the Outboard. HELP! I really want to get her out on the water this season.

Thanks! Chris

Do you have a 4bbl down draft carburator? Electric choke? I have a manual for a 1965 90hp johnson that might have some info. Sometimes they can shut down do to lack of cooling. Is there enough water coming out of the exhaust port?

Yes - 4bbl. Have a manual for the boat, but not much help! I will take a look at the Water pump, but I did rebuild it and put in a new impeller?? worth a shot. Thanks!

Chris,
Have you been able to get a spark again since it sputtered the last time? When you stated no spark, was it from the coil to ground or from the spark plug to ground? If no spark out of the coil to ground make sure you have 12 volts to the coil primary. If no spark out of the spark plug lead to ground, first check to make sure that the breakers (points under the cap) are opening and closing properly with the correct gap.

Will

Chris

My first new outboard was a 1968 100 hp Evinrude, same as yours except for color and remote control.

I was an outboard mechanic in high school for an Evinrude dealer. Worked on mine and a lot of customer's. Engines were great except for the electrical system. I quickly learned to trouble shoot them by using the factory manual, lots of checks and a wiring diagram. Still have a manual. if you need I can send email copy of electrical part.

Never saw your problem, but with the electrical check list you should be able to find it.

Unfortunately decided to give up on the 100hp Johnson. Picked up a 1984 115hp Mercury inline 6. Have it on my 67' Thompson offshore and hope to have her in the water soon!

Anyone know a good place to sell my 100hp Johnson? Had it on eBay a few times and no bites. Figure I need to find a site that is for older OB's. Still a good OB and finaly got her running , but just not experienced enough to get her running right.

Appreciate the recommendations!
Thanks!

List it on the AOMCl.org web site.
All old outboards,all the time.
Karl.

also www.fiberglassics.com. also an outstanding source for help in troubleshooting odd issues (the forums)