Still no idle

[87Merc115]

Cleaned the carbs again found the needles were plugged up. Yesterday, I had the timing set, and seemed to idle okay. Today put a timing light on the engine and adjusted the idle timing to 25 degree's BTDC. Checked timing with motor in gear, and was steady at 25 degree's. The weird thing is now when the motor starts it rev's very high then drops down to close to an idle and then dies. Lots of smoke. I was thinking maybe my mixture is a little on the rich side but have yet to get it to idle long enough to set the idle/Air mixture. Just rebuilt the fuel pump as well. The fuel supply is good just not sure what could be causing this. The motor is a 115 inline 4.

 

[CharlieB]

Re: Still no idle

Do you have the manual for this motor?

MAXIMUM timing at WOT is more likely 25 BTDC

As the throttle is reduces so should the timing until near 0 at an idle.

Idle speed is set by adjusting idle timing and idle mixture.

Set idle timing about 4, idle mixture screws out 1 & 1/2 turns out from lightly seated, adjust idle mixture to best idle plus 1/4 turn out then set idle speed with timing advance or retard to bring idle speed to 800.