89' tohatsu 25 horse

[Bgtmfsher77]

Hi everyone,

I purchased this motor today and was told that it might a new CD Ignition unit as spark was leaking out of the bottom of the boot and the motor was missing. I am very much a novice at boat motors so had a couple questions. I cut the wire down a little and put a new boot on but noticed some spark coming out of the bottom of the boot at times still. I also pulled the wire from the spark plug when it was running and it didn't change the way it was running at all.... Now like I said I dont know much about outboards so not sure if it really is missing the entire time and I just can't tell. Should the motor run significantly different when pulling one plug? I'm really hoping I don't have to change the cd ign unit as its 250-300$ so just trying to make sure that's what it is. Thanks for any help.

Brandon

 

[pvanv]

Re: 89' tohatsu 25 horse

Brandon,

What is your exact model/serial? Do you have a fouled plug? If spark is jumping off instead of going to the plug electrode, that is the path of least resistance. I doubt that the CD is bad. You will need a good analog meter and a Factory service manual (available from any dealer, including me) to properly dx the problem.

 

[Bgtmfsher77]

Re: 89' tohatsu 25 horse

Brandon,



What is your exact model/serial? Do you have a fouled plug? If spark is jumping off instead of going to the plug electrode, that is the path of least resistance. I doubt that the CD is bad. You will need a good analog meter and a Factory service manual (available from any dealer, including me) to properly dx the problem.

The model is NS25C2. I changed the plugs and it had the same problem. The guy I bought it from said a mechanic told him it was cdi

 

[pvanv]

Re: 89' tohatsu 25 horse

I don't have any documentation older than the 25C3. That motor has a separate CD unit and a siamese (both plugs connect to it) ignition coil. In that arrangement, a CD problem will NOT cause spark to leak from a plug boot. Your setup may be older/different, but I would not armchair diagnose a nad cd from your symptoms.

Yes the motor should slow significantly if you pull/ground one plug wire. What happens if you pull/ground the other wire instead?

What is your compression?