Lost half the plugs!! Yam 115 BETO (1996)

[LewisB]

Guys,

I've got a Yam 115 BETO V4(1996), been suffering intermittent power loss and whilst bringing the boat up the river the other day I lost power again, took out the plugs and saw that the both the port side were wet and oily, and the stbd side dry.

Does the loss of just the port side plugs immediatly give any of you guys an idea of what it can be? I initially thought I was losing one and that maybe I had a bad coil - but two at the same time? I'm borrowing a peak voltmeter to check that this weekend.

The sparkplugs are new this season, so is the fuel pump and the carbs were cleaned 4 weeks ago (for the 3rd time!) so i'm pretty happy its not the fuel that is the problem.

So, anyone had this and is it a pointer to an obvious problem?

Got a manual and tools....just need to know which bit to check/fix

thanks

Lew

 

[douglloyd]

Re: Lost half the plugs!! Yam 115 BETO (1996)

When it happened to me it was the CDI box. Got one used from a dealer.
The first tech diagnosed as trigger points that wasn't it.

 

[LewisB]

Re: Lost half the plugs!! Yam 115 BETO (1996)

Thanks Douglloyd, I'm going to check the stator, CDI and coils and hope that I get an indication that one of those is not working.

I will not get to the boat till the weekend but i'll run through the checks then.

Thanks again,

Lew

 

[LewisB]

Re: Lost half the plugs!! Yam 115 BETO (1996)

Well after too long with work getting in the way of sorting out my boat, I managed to do the tests suggested. All resistance tests checked out ok on the stator, coils, etc. This indicated that it was probably the CDI. I replaced the CDI and I've now done two runs of about 10 miles each and it sounds like a new engine, quiet and looks to be a bit more fuel efficient. Sea state has been a bit lumpy to really open her up but its more responsive than before.

I think I've been running round with a failing CDI for some time for it make such a change to the engine.

I hope this helps anyone else with a similar problem

thanks for your help all,

Lew