thermo advance on my c40tlrw 1998 yamaha ob?

[takara]

Can anyone tell me if I have some type of cold start thermo device that advances the timing on a cold engine until hot, then lets the timing return to the normal idle setting? I am aware of the fuel enrichment valve and how it works, but my Seloc also refers to this thermo device for timing advance on cold engines. I want to pull the s/plugs, spin the engine, and check idle timing with a light. If there is a cold start advance on my engine I will get the advance degree reading, not the normal reading. If I do have one I will have to locate and disable the device to check the timing. Any help will be appreciated. thanks

 

[pine island fred]

Re: thermo advance on my c40tlrw 1998 yamaha ob?

New one on me, never heard of advancing the timing on a cold motor. If anything you would want to retard the spark. Long time ago there were spark controls on the steering column. Retard the spark, hand crank the motor, then go back and advance the spark. Is also possible that when REAL men had to kick start their chain drive HARLEYS, there was a retarding lever to prevent the motor from firing before TDC and kicking the operator off. However, if SELOC says it is there, has to be something to it. FRED

 

[99yam40]

Re: thermo advance on my c40tlrw 1998 yamaha ob?

Yes the CDI box advances the timing electronically at start up to get higher RPMs until the temperature switch closes and then it returns to normal timing and RPM.
If you look at the head there are 2 switches one with the pink wire is for over temp and the other for engine warmed up.

Spinning a motor without the spark plugs hooked up to the wires and not a place for the spark to jump to can cause the spark to jump internally to what ever it can and may harm windings or other things. It is always best to short the wires to ground through a spark tester to give the spark someplace to go.

Setting spark is normally done by adjusting the wiper to the mark on the CDI box like the manual states and then checking while motor is idling and warmed up. Adjusting linkage as needed and rechecking

 

[takara]

Re: thermo advance on my c40tlrw 1998 yamaha ob?

Thanks for the help, Ill check out thses switches, aint no way anyone can learn to much about these engines. Found out my retard stop screw adj. is 22 instead of 20mm (Seloc). This could have some effect on my timing because this is where you start linkage set up. The boat is 150 miles south so I try to get as much info as I can before I go down there. Aint no computers or reference books there. Ill be asking questions for a few days so any time you can help out please do. Thanks