1988 115hp CDI problems? Need Help

[brett]

I have a 88 115hp V4 that is very inconsistant at starting. Appears to have a weak spark sometimes. Does anyone have a method to test the CDI module? When I measure the coils for the charge and trigger coils, I get values that make reasonable sense. Any help, advice, or procedure would greatly be appreciated.

Thanks,
Brett

[jb123]

inconsistant starting ? how does it run when it starts? if it were electrical it would run bad the whole time. i`d suggest checking pickup tube screens,all fuel fittings,separators,filters,delete quick disconnects and a good carb cleaning. it is sooo cheap to replace all fuel lines to alleviate any future problems. also, your motor is aged so the wires are gettin brittle,run it at night to look for coil leakage, you might have to expose the coil leads.

[Ken]

Brett,
To do the type of testing of the coils that you want, you really need the Yamaha shop manual for your particular model.
You might want to check the choke on that 115. When you engage the electric choke, make sure the butterfly valves in the throats of the carbs are closing all the way - if they don't, that little V-4 is hard to start. Pull the manual choke, which should close the butterflies all the way and compare to the electric choke. You may need to do some adjusting of linkage on the electric choke.
Good luck,
Ken K