Re: 1991 40 hp yamaha #3 cylinder
hello<br />nope that model does not have the CDI that kills a cyl at any speed unless its on the rev limiter. <br /> its rare a yamaha coil fails. usually its a poor ground and yes then it can come and go.<br /><br /> the CDI can fail and only affect one cyl.<br /><br /> the 91 40 has 3 pulser coils. a failure of one will affect that cyl.<br /> a "galling" cyl means a piston is sticking. your compression numbers dont indicate it.<br /> to test the CDI charge coils and the pulser coil outputs as well as the CDI output you MUST uses a peak reading multimeter. no other meter will work. there are some adapters to use on some digital meters called a DVA adapter. I dont own one of those but I do own 3 cd-77 meters and the merc one. I dont like digital for CDI testing. the resistance test is iffy but heres some numbers.#1 cyl white red to black 196 ohms w/b to black is #2 196 Ohms and W/G to Black is #3 196 ohms.
hello<br />nope that model does not have the CDI that kills a cyl at any speed unless its on the rev limiter. <br /> its rare a yamaha coil fails. usually its a poor ground and yes then it can come and go.<br /><br /> the CDI can fail and only affect one cyl.<br /><br /> the 91 40 has 3 pulser coils. a failure of one will affect that cyl.<br /> a "galling" cyl means a piston is sticking. your compression numbers dont indicate it.<br /> to test the CDI charge coils and the pulser coil outputs as well as the CDI output you MUST uses a peak reading multimeter. no other meter will work. there are some adapters to use on some digital meters called a DVA adapter. I dont own one of those but I do own 3 cd-77 meters and the merc one. I dont like digital for CDI testing. the resistance test is iffy but heres some numbers.#1 cyl white red to black 196 ohms w/b to black is #2 196 Ohms and W/G to Black is #3 196 ohms.
This weekend i will pull apart the hole electrical system clean all contacts. And I guess I will soak the carb at the same time.<br /><br />there is a broken ground wire that got pinched off behind the starter the wire is doubled 1 wire goes to one of the trim relays and the one that is pinched is in the same eye ring but cant find its partner <br /><br /> 