retarded F40TLRC

Henry D. · #1 (**permalink**) 07-28-2010, 04:39 PM

Have A F40 Yamaha that Ignition timing is running 5*retarded instead of 5* advanced. Have replaced flywheel sensor & CDI unit (no help).anybody run into this before?
New find: If I disconnect the thermo switch the timing retards to 10*???

99yam40 · #2 (**permalink**) 07-28-2010, 04:45 PM

My C40 starts and warms up at 5-7 BTDC but after warm up idles at 7 ATDC .

It is designed to do that. have you checked your manual to see what it says?

Henry D. · #3 (**permalink**) 07-29-2010, 09:23 AM

My Yamaha manual calls for 8 to 28 degrees btdc

boats.net · #4 (**permalink**) 08-01-2010, 10:32 PM

At idle it will run about 5 degrees before top dead center.

Henry D. · #5 (**permalink**) 08-02-2010, 01:00 PM

Quote:

Originally Posted by boats.net

At idle it will run about 5 degrees before top dead center.

Got any suggestions to change timing from 5*atdc to 5*btdc. have replaced pulsar coil & cdi unit. Thermo switch checks out for resistance. Oil press switch is closed (engine off) & open (engine on). My manual indicates it should the opposite.