1977 70hp johnson project

[Fowl_obsession]

we are moving along on our boat build project. after taking the boat to a mechanic we found that the power pack was bad causing the center cylinder not to fire. i had the starter rebuilt which fired the moror up about 10 times before going bad again. when it did fire, it would only do it while being choked then it would rev really high and cut off. any idea on what could be causing this?

 

[sutor623]

Have you checked the battery cables for internal corrosion? Did you replace the starter solenoid as well? Normally if the motor revs really high like that there is a chance the motor is running lean or has an air leak somewhere, or the timing is off.

 

[emdsapmgr]

You may want to also check these ignition components: timer base and stator. If you check out the on-line ignition troubleshooting guide at: cdielectronics.com, you will find some excellent tips on how to test both components: done while the engine is being cranked. You will need a special "peak reading" voltmeter in order to validate both items.