Evinrude 6hp fuel consumption

[Tunkioperho]

Hi!
I have Evinrude 6hp 1979 model 69B66E.

I?m worried about the fuel consumption of the engine, 8 litres or about 2 gallons/hour when driving on full throttle.

Motor starts everytime on firts pull, never had to use choke when starting, when idling or running at low rpm the motor just barely keeps alive whitout stalling.
Motor allso revs very slow even whitout on gear.
I just got the motor so i have no idea how much power it should have but it feels like it is lacking some power, even my 4hp tohatsu outruns this evinrude monster anytime.

I changed new spark plugs but no affect.
Both cylindes seems to fire equally.
Compression on cylinders are 82 and 80 psi.
I checked that the carburettor doesent leak.

Any ideas what should i do with the engine?

P.S. sorry about my bad english, i?m from Finland and english is a bit dificult for me.

 

[JB]

Re: Evinrude 6hp fuel consumption

Hello, Tunki.

I think your engine is running very rich. Check the float level in the carburetor and the sealing of the inlet needle.

When running, see what effect you get if you turn the high speed mixture control a bit clockwise.

Finally, if all else fails, get a factory Service Manual and perform the linkage and synchronization procedure.

Good luck, and let us know how it responds.

P.S. Your English is a lot better than many people who have been using it all their lives.

 

[Tunkioperho]

Re: Evinrude 6hp fuel consumption

Thank you JB for quick response!

I don't think there is high speed mixture screw on this model. Or is there?

I just disassembled the carburettor, it was clean and float level was ok. Allso float valve was ok.

High speed nozzle gasket was only part that looked pretty akward.
Can it affect the carburettor fuel intake if it leaks?
Part number 21 on this page: http://www.marineengine.com/parts/j...905E&manufacturer=Evinrude&section=Carburetor

 

[SeaKaye12]

Re: Evinrude 6hp fuel consumption

Yes that could be it. Called a boss gasket among other things. Sometimes supplied as a cork gasket in the rebuild kits; quite thick. I've heard of people using a proper size O-ring there as well if a gasket is not available.

The proper gasket is so thick that it has to be squeezed when assembling the bowl. That's normal.

Chuck

 

[AlTn]

Re: Evinrude 6hp fuel consumption

make certain that each cylinder's spark is capable of jumping a 7/16" < 12mm or so > open air gap

 

[boobie]

Re: Evinrude 6hp fuel consumption

The old rule of thumb for fuel consumption is 10 % of the horsepower at WOT. Your mtr should use .6 gal per hr.

 

[Tunkioperho]

Re: Evinrude 6hp fuel consumption

Carburettor has now new gaskets, high speed nozzle and float.
Spark tested without any specific tester, but spark jumps easily at least 1/2". Spark plugs are NGK BPR6HS are those ok?

I haven't measured the fuel consuption yet, but at tank testing it still sounds a bit lazy.
Motor revs up quite slowly and just before top revs without gear on it starts to cough very badly, and allmost stalls because huge amount of unburned fuel on cylinders.

Next step might be the carburettor/ignition synchronization.
Does anyone have any easy advice for the synchrozation operation? I found some old pdf. documents about it, but those were pretty complicated and hard to understand.

 

[AlTn]

Re: Evinrude 6hp fuel consumption

google..leeroysramblings...outboard motor related articles...6 hp....that should help you....the synchornization process on your motor is really simple, carb roller on timing cam mark just as the throttle plate < not choke plate > begins to open...then at wot < wide open throttle > the roller is at the highest point on the cam and the throttle plate should be perfectly horizontal in the carb throat

 

[Tunkioperho]

Re: Evinrude 6hp fuel consumption

Thank you AITn!
Sync was way off.
Throttle plate was horizontal when cam follower was in halfway of the throttle cam, at full throttle the plate was closing 1/4 of the throat.

Now it runs smoothly and revs up without any hesitation.

Thank you all for helping and smooth sailing!


With best regads, Tunkioperho from Finland