wot timing

[riverboy39]

can anybody tell me what the wot timing should be on a 1975 mercury 65 hp 3 cyl. 23 or 27 degrees thanks.

 

[Texasmark]

If nobody answers try one and then the other. One thing to consider, if you have back drag carburetion whereby you go to full throttle and butterflies open fully and spark timing is fully advanced, and then cut the throttle back slightly, the spark remains full advanced and the fuel volume is reduced.....reason is Merc's economy of operation idea.

If running 87 octane fuel you might get some pinging (spark dedonation) which can burn a hole in your pistons. If you decided to go to 27 and you experience the problem you either go back to 23 or get premium fuel. Each engine is different but I don't recall having an engine WOT timed up at 27 BTDC.

 

[riverboy39]

thank you for the response .

 

[Faztbullet]

Wot timing is 23° and cranking setting is 25°as reduces 2° at RPM.

 

[riverboy39]

setting it at 25 thanks for the info .

 

[jimmbo]

There is no white sticker slapped on the engine that states the factory timing?