1986 yam 115 cdi unit

[kcjones1504]

I have taken the boat in to the shop. Im starting to wounder about mechanics. 300 to 1 guy to rebuild lower carb and i rebuilt upper carb. Although I have had rebuilt both carbs and checked air leaks and so on. Couldn't get it to go right. Shop calls and says they can't figure out the cdi unit or the coil packs with the omh meter. Said I had no spark to two plugs and changed around a wire on something and got all 4 to fire then put wires back the right way and still all 4 fire. Thier telling me it could be the cdi unit or pulsar coils. Sounds like a bad ground wire to me, OR could it be a bad cdi unit or coils if all are working now? cost 300 just for them to tell me this. is this common to spend 5 hours checking on spark and timning? And still not besure if its that or not. Please help on this matter. I did disconnect the white wire on the cdi box and had fire. so whats next change both out?

Thanks K.C

[99yam40]

I would think it was not a Yamaha shop you took it to.
A Yamaha service manual and the proper test equipment should show what the problem is if it is electrical

[kcjones1504]

Starting to wounder. The dealer I tolk it to in omaha neb. has been here awhile not sure on the mechanic, The service guy said it tolk them 5 hours to say the cdi unit or pulsur coil is bad the couldn't figure out how to test the cdi because it was japan and eng jumbo not sure what that means. They stated that they fliped the bottom 4 wires believe they are 6789 and got spark on all plugs fliped them back and still had spark on all 4. If the CDI unit was bad it would it stay bad and if the pulsur coil was bad it would have no power on the plugs? anyways boat is running now. but don't want to get on the water and have it happen again. how long should it take to check cdi and spark? thanks again for all your help.

KC

[99yam40]

I would think less than an hour, but I know almost nothing about motor that old.
Testing charge coils, pulsar coils, and CDI output should not take very long, but as I said I have no idea if that motor is like the newer ones

[rodbolt17]

its just like the newer ones.
you test the charge coil inputs to the CDI, test the pulsar coil inputs to the CDI then test the CDI output.
using test wheel YB1624 and a peak reading meter this all takes about an hour for a trained tech.

[kcjones1504]

Thats what I thought. Its a sham a big boat dealer would hit me with 330. for the work they did to it. ? Rob if you don't have fire to two plugs and you flip the wires in the CDI unit around and you get fire and then put it back the way it was and have fire again, Does that mean the CDI or the Pulsar coil is going bad or just a bad connection or ground wire. I sent the GM of the boat shop an email not sure what that will do but thank you guys for all your help.

[seahorse5]

An engine that comes in with no spark and it turns out to be a bad CDI box doesn't take too long to find out the problem. But if the problem is intermittent and may take an hour of running before it occurs, then troubleshooting time can be a lot longer. Talk to the dealer and see what he says.

[kcjones1504]

The eng went in for a sink and link just to tune up the motor and to make sure the timming was set right. (that they didn't do). Eng ran fine b4 going to them had fouled plugs do to air flow valve. Came back starts right up and no probs, So I'm still not sure what all they did. Woundering if it was a bad connection, But the fact remains they didn't do what they said they were going to do. They said tolk them 5 hours to check cdi unit and pulsar coil, Thing is if you think that something is wrong dont you check it with the meter and not guess what it might be I mean they are a dealer. But then again Im just a guy trying to get back to the lake, I ended up doing the link and sink my self and the boat is running fine now. Still not sure about the timming on it it has a slight shake. But other then that running fine, Makes me wounder. anyways thats for all your help.