1974 9.9 one cylinder frustrations

[ironworker]

i have a 74 evinrude 9.9 that insists on running on the number 1 cylinder only. quick rundown... good compression(105 in the number1, 110 in the number 2), fuel pump rebuild, new gas, carb cleaned inspected, new plugs, points filed and cleaned regapped. i felt like it was electrical so i started switching the electrical components to try and isolate the weak link. all electrical parts look good. Coils, condensers, points, chased all the wiring for pin holes. number one runs on all of them, number 2 wont. number two cylinder has spark, (i have a compression spark tester gapped at 1/4 inch and the spark looks the same as 1) is getting fuel mix in the cylinder and is forcing unburned fuel out the exhaust. Starting to feel like a valve issue but i dont know enough... any insight would be greatly appriciated... by the way i am new to this site and already i have learned a lot. thank you to everyone involved

 

[oldrudedude]

Re: 1974 9.9 one cylinder frustrations

Are you saying you swapped out all the ignition components for# 2 with no change? But you are getting good spark on #2? How do you know number two is not running? Have you strobe checked timing on #2? Is this a new motor to you? Do you know the history?

 

[Rick.]

Re: 1974 9.9 one cylinder frustrations

A stranger set of circumstances for you. How does the non-firing cylinder plug look after it has run for a bit. Wet or dry? Have you pulled the plug wires while running to determine #2 isn't running? If your fuel pump gasket has a leak where it connects to the power head I've been told it will draw gas straight into the #2 cylinder and flood it. I have not experienced it but it may be worth checking. oldrudedude has asked some good questions that I would be interested in hearing answers to as well. Here is a great site for us 9.9 and 15 owners. I feel it is a must read for us. It may hold the answer to your problem and it may not but you will learn lots reading it. Best of luck. Rick.

http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm

 

[ironworker]

Re: 1974 9.9 one cylinder frustrations

i switched all the ignition parts, one set at a time (coils, then condensers, points, 3 sets of new plugs...) and it fired easily every time on number 1. i would pull the plug wires one at a time, and it would run with 2 pulled with no noticable change, but would die immediately when 1 was pulled. Dont know about strobe testing, what is it? checked the flywheel key and it looks new and doesn't seem to have any slop. It seems to have decent spark... blue same size as number 1

 

[ironworker]

Re: 1974 9.9 one cylinder frustrations

hey oldrudedude, the motor is new to me, i picked it up for a song and the first time i ran it something felt wrong. it wasnt idling well and felt under powered. im new to 2 stroke outboards so i started poking around. i dont know the history, but it looks loved

 

[JB]

Re: 1974 9.9 one cylinder frustrations

GRRRRRR! Double post.