Missing/Rough idle

[MillBubb]

1968 Evinrude, 65 Horse - Sport Four
Hi All! New boater here. First want to say what a blessing this site is and also great motivation. I reciently aquired this Lapline and was told it had a new power pack but still needed carb work. To Date I've done... 1) Carb Kit. 2) Compresion test (1/3 90psi) (2/4 80psi). 3) Sparks jump 1/4" on all 4. 4) Decarb. 5) New lower unit seals and impeller. 6) When I pull the plugs on 2 or 4 It dosent make a very noticeable rev drop and both plugs are dark and wet. When I pull the 1 or 3 wires the motor stalls and those plugs look correct-slightly tan and dry. Another couriosity.. When trying to set the lowspeed idle, the PORT side responds as expected but the Starboard needle dosen't make a smooth setting. This would make sense if it was supplying the weak 2/4 cylinders.
Thanks for any suggestions!

 

[tashasdaddy]

Re: Missing/Rough idle

i would say that 2 and 4 are not running. if wet they are either flooding, or not getting good spark.

 

[MillBubb]

Re: Missing/Rough idle

Could this carb be a "cross Flow", Right barrel feeds Cylinders 2 and 4? I guess it could be flooding. New question; does the low speed needle need 4 packing washers? The parts break-down look like four.?

 

[Evinrude Boater]

Re: Missing/Rough idle

Do you have four spark testers that you can install and watch them while it runs? You say you have spark on all four but your plugs seem to indicate otherwise. How does it run at high speed? Good power?

 

[MillBubb]

Re: Missing/Rough idle

I haven't tried a tester yet, just held it close to the block and watched the spark jump. It did look a little erratic though. Not a quick bold jolt like 1 and 3 did. (it started once with three plugs dissconnected!) It will get up to high speed after a stall. At high speed it will have a frequient "hard" miss.