1979 115 rower of power outboard no idle

[Georgesalmon]

Sooo, long story short. Couple of years ago rebuilt carbs, new fuel hose's etc. Ran fine two years. Last fall last trip started missing at idle. Left till spring, put in new plugs this year. Seemed OK on muffs. Will not idle at less than 1200rpm and will stop when put in gear. If can get it in gear it is fine accelerates fine reaches WOT rpm, etc. Have adjusted idle screws several times like book says. still won't idle. Can't be starved for fuel or fuel pump as its WOT perfect. Can't be swithbox as its fine at WOT.


No distb. or idle stab on this one either.

 

[444]

Plugged idle or low speed passage in one carb? Don't forget to do a link and sync after you pull the carbs apart.

 

[Georgesalmon]

Did linc and sync. Also, if I can adjust the needles and achieve on all three carbs the points where its to rich and to lean doesn't that mean my passages are clean? I mean I can adjust according to the manual. But that's at 1200 rpm. I know I have to go to the water to finish this but it won't even idle on muffs.

 

[Chris1956]

George, 1200 RPM is about the time the main jets in the carbs kick in. To me that indicates you have clogged idle passages. Make sure those pesky pin holes in the throat of the carbs are clean, as well as the idle restrictor and the other passages.

 

[racerone]

Waterpump impeller been inspected / replaced recently ?----Compression test done?---Checked for good spark on all leads ?----Check bleed restrictors ?---Make no assumptions when trouble shooting.

 

[Mi duckdown]

1200 rpms is tough on the lower end when shifted into gear. should be about 800/900 if the tach is correct. when I rebuild carbs. I used 25 lb mono fishing line thru All passage to make sure they are clean.

 

[Georgesalmon]

Thanks fellers. Guess 'll pull those darn carbs off today.

 

[Georgesalmon]

well, pulled off carbs, looked clean, blew them out anyway. Every itty bitty hole is open. No help. Still won't idle below 1200rpm.
Next, I rechecked the lync and sync. every thing I can do checked out. No dial indicator sO I can't check the pointer, but its not been moved.

What next? It still runs fast just fine if I can get it there.

 

[Chris1956]

George, You can use a caliper or steel ruler to set the timing pointer. Measure to the top of piston #1, and add .464 inches to that number. Now turn the flywheel CCW 1/4 turn. Stick the caliper or ruler into the plug hole to the sum of the depths, and turn the flywheel until the piston hits the caliper/ruler. Set the timing pointer to .464 BTDC.

On another thought, whereas you have set the idle pickup timing to 0-9* ATDC, you can use the throttle to retard the timing until the motor slows down. Loosen the idle stop screw, and adjust the throttle cable barrel nut to push the throttle closed, and retard the timing some more, until you get 900 RPM or so.

 

[Georgesalmon]

Hmmmmm, you said 0-9 ATDC??? My book says primary pickup-idle timing is 4-6 BTDC.

And thanks for the tip of using a caliper, I'll do that just for peace of mind.

 

[Chris1956]

George, 0-9* ATDC is the idle pickup spec for ADI ignition. 4-6* BTDC is the spec for battery powered (distributor) CDI Ignition.