89 Yamaha 40HP idle/full throttle problem

[nussbaum_99]

Hi all, I have a 1989 Yamaha 40HP outboard that i can either get it to idle or be able to go full throttle depending on how i adjust the linkage on the CDI box. If i adjust the linkage so that it will idle good, when i go full throttle the linkage over extends and jams and stays full throttle and if I adjust it so it will not jam then it will start and idle for about 5 seconds then kill. I would just replace the CDI box but at $400 and everything i have read on them they either work or they don't. Has anyone seen or heard of this?

Thank you for any help given.

[99yam40]

might help if you post your complete model # ID

[nussbaum_99]

sorry 40ETLF

[99yam40]

I see no CDI itself listed on the parts diagrams for some reason.
but with mechanical timing linkage, I would be looking for loose or bad bushings/ linkage.
looks like the timing plate just moves the coils around to set the timing.

also see if all of the coils on plate are putting out in spec voltages.
checking to see what timing is with a light may help see what is going on

[panasonic]

Do you have the Yamaha manual to be sure you are adjusting the linkage properly? Or are you just winging it?