1981 115 HP Evinrude - rough idle, hard to start

svdk

Seaman Apprentice
Joined
Jul 29, 2005
Messages
36
Condition: Engine is tough to start and idles rough (mildly) but eventually dies (seems to not get enough fuel) if I keep it close to idle (for trolling). Under full load the engine runs like a champ.

Engine did not have this problem in the spring. It sat idle for a couple of the summer months and just exhibited this problem. No changes to method of operation or equipment that I know of.

Question: I'm thinking this is a carb issue, probably just gummed up a little from sitting idle during a couple months this summer. Is there an easy approach to cleaning the carbs with some type of fuel additive.

Thanks,
Stephen
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 1981 115 HP Evinrude - rough idle, hard to start

Nope, you are going to have to pull them and clean them properly.
 

keefallan

Petty Officer 1st Class
Joined
Jun 23, 2010
Messages
219
Re: 1981 115 HP Evinrude - rough idle, hard to start

It sounds like the idle circuits are gummed up(runs good at high rpms). Make sure you run something thru the idle passages that run from the float bowl up to the top. I had to use some fine copper wire strands twisted together to get the gum out of mine. Ran like a champ after that......
 

Mburucuya1

Cadet
Joined
Aug 19, 2010
Messages
6
Re: 1981 115 HP Evinrude - rough idle, hard to start

You can use soft brushes, that you can get at the hardware store, the one to clean paint spray, I just bought some fronm the store today to recheck my carbs passages, good lock.
 

Al-53

Chief Petty Officer
Joined
Jul 17, 2008
Messages
491
Re: 1981 115 HP Evinrude - rough idle, hard to start

the wire in bread ties work good also.....and those plastic tooth picks with a little brush on one end and a point on the other end

Al
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1981 115 HP Evinrude - rough idle, hard to start

Use a can of aerosol carb cleaner to blow out the passages in the upper carb body. Compare the flow from one passage to the same passage in the other carb. Make sure they all flow the same prior to reassembly.
 
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