1985 120 Evinrude

[daleb]

When I first start the motor it runs good for aboult 3 minutes then I loose 2 cyl's on same side, if I hit the choke for a second or 2 it runs on all 4 for a few seconds and I loose the same 2 cyl's again. Its getting spark and I went over carbs, could it be fuel press ? it has a VRO pump but I'm running a pre mix and oil inlet comming into motor by fuel inlet is plugged off. Or in ign system ?
Thanks
Dale

 

[kenmyfam]

Re: 1985 120 Evinrude

Sounds like fuel restriction to those cylinders. Elaborate a little on the "went over carb's" statement. Does it improve if you squeeze the fuel bulb ??
Welcome to iboats

 

[tashasdaddy]

Re: 1985 120 Evinrude

Which cylinders are you loosing?

confusing. only has one power pack, the top carbs are for the top cylinders, bottom for bottom.

 

[daleb]

Re: 1985 120 Evinrude

I cleaned the carbs and the 2 jets on the front of carbs, checked float levels and all seems good. The ball stays hard and no improvment when I squeze it. Its the 2 port cyl's, I can pull off the plug wire's when its running and there is no change, I can hear and feel the spark.

 

[tashasdaddy]

Re: 1985 120 Evinrude

seeing that it is the port cylinders not firing, check for power pack, coils, other electrical. but seeing you did not service the carbs properly, it still could be them. do some reading here http://forums.iboats.com/showthread.php?t=299680

those carbs have 6 jets in them, 3 for each cylinder. #3,5 15. in the diagram http://shop2.evinrude.com/ext/index.aspx?s1=86d3d72aeba35dacbc349b439cb45104

3 and 5 are in the upper 1/2 of the carb, 15 is deep behind the drain plug, on each side of the carb. also use a rebuild kit
http://shop2.evinrude.com/ext/index.aspx?s1=86d3d72aeba35dacbc349b439cb45104

 

[kenmyfam]

Re: 1985 120 Evinrude

Agree completely with doing a full carb service.

 

[daleb]

Re: 1985 120 Evinrude

Thanks for the info, the one thing that I didn't do is when I serviced the carbs I didn't replace the needle and seat which to the eye looked good but I will replace them know and try that. As far as the jets I didn't mention the one behind the drain but I had removed all the jets ( 2 front which I beleive are idle,mid and the one behind drain is the high speed ) I also removed needle and seat then soaked in a kerosene and crc mix and blew through all the orfaces etc. Never the less I going to take your suggestions and do the complete rebuild w/new parts. I am seeing some wetness on the spark plugs there not completely wet but they are getting some fuel possibly not enough . I wiil keep you updated. Thanks again..

Dale