1991 Johnson 155 HP Commercial Sputters and backfires but will not start.

[weirbt]

After opening the manual primer for about 10 seconds the motor will spudder and back fire but will not start. Almost seems as if it runs and then runs out of gas. Tried maintaining this by pumping the bulb but it still quits. Bulb does remain hard the entire time. I have cut and plugged the oil line to the VRO and premixed in the tank to remove the chance the VRO is over oiling and fowling the plugs. Also noticed the spark on all plugs is very dim or not existent but since it sputters and tries I figured this may be OK.

Any ideas on what next to try?

Thanks

 

[boobie]

Re: 1991 Johnson 155 HP Commercial Sputters and backfires but will not start.

First thing to do is check the compression. Sounds like you have an ignition prob so get an open air gap spark tester and set it at 7/16 ". If no spark, go to CDI Electronics.com as they have good troubleshooting procedures.