1978 115 No spark

bigguy6f4

Seaman
Joined
Aug 2, 2007
Messages
61
Inherited my fathers old boat and motor. Dad said it ran fine last fall when he last used it, But couldnt get it to start recently. I installed a new fully charged battery and pulled the plugs and they looked great. Hooked up my timing light and NOT showing any spark. I did happen to find a Repair manual at a store as well as the downloadable ones here online. However since These things are a little bit different than the old trucks i work on I thought i best ask the pro's where they think i should start.

Here are a couple things i did before I noticed no spark.
I did do a compression test but not a leakdown test. (cant find my leakdown tester at the moment.) but all cylinders are around 120 and within a few psi of eachother. Seems to be getting plenty of fuel. When i choke it i can see some fuel dripping out when the engine is trimmed up.

Plugs looked great. Plug wires look old. I did see online that these things can be easily injured if someone tinks around the electrical system. So before i fry something I again call on you guys to help me out. Thanks!
 

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: 1978 115 No spark

my guess is stator..or wiring issue. you need to test your stator, switch boxes..you will need a multi meter and a DVA adapter and a spark gap tester. look you parts up on CDI electronics web site and download the install sheet, this has the test process for each part. Or just guess at it and start changing parts..I would start with the stator..,.
 

turtles11756

Petty Officer 1st Class
Joined
Dec 5, 2007
Messages
260
Re: 1978 115 No spark

fuel will drip when priming, the motor will not spark while tilted up due to a safety switch to stop spark. begin by closely checking condition of all wiring .stop back here , the parts are available if needed. it will fire , and the lower unit must be in water or on muffs at the intake when it does. and take care of your Dad's old black beast
 
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