Carburetor or Fuel or Electric???? Clear Description. Stumped????

[Joedice456]

I have a 1978 Johnson 85hp outboard motor that left me stranded the other day.
Had a refurbished impeller installed before the summer.
It ran great all summer over 10+ trips. The motor has been sitting for about 30 days since last trip out.
It had about 3 gallons of fuel since last trip so i put another 9 gallons in that morning.
Went to start the motor and it wouldn't fire up.
It was turning over fine but just wouldn't start. I changed spark plugs. Checked fuel lines.
Everything looked fine. But still nothing.
I bought a can of the carburetor starter fluid. Sprayed it in the carb and boom she started right up.
Took off the earmuffs and went down to the water. Again started up fine in the water.
Started heading out of the canal in 5 mph wake zone. once I tried to open her up she started stuttering.
It sounded like she wanted to go but just wouldn't reach her max rpm.
Kept trying to throttle down and then throttle back up to catch it in between stutters and eventually i caught it at the right time and got her to full rpms.
After 4 hours of boating I ran out of fuel. This is extremely unusual since I can usually go out all day on a full tank.

After reading on the forums I am assuming it could be one of my floats in the carburetors that was stuck open.
Is there any chance the fuel went bad after sitting for 30 days? Would bad fuel cause these types of symptoms?
I am wondering if anyone has any other ideas on what it could be before I bring it in the mechanics to have the carbs rebuilt.
What should I do before bringing in to rule out any other problems?
Would it too hard of a job to do myself. Should I order the manual and give it a go?

Thank you in advance for looking through the thread and any advice you can give. I am new to Boating and continue to learn something everyday I am out on the water.

 

[metriccrescentwrench]

Had a refurbished impeller installed before the summer.

While this has nothing to do with you problem it piqued my curiosity as to how the heck someone could 'refurbish' an impeller.

I bought a can of the carburetor starter fluid. Sprayed it in the carb and boom she started right up.

DON'T DO THAT!!!! Starter fluid will instantly wash all oil off of cylinder walls and bearings. That's a very fast way to do serious damage.

Is there any chance the fuel went bad after sitting for 30 days? Would bad fuel cause these types of symptoms?

No way did gas go bad after sitting 30 days. If you want to give yourself a little peace of mind on this issue you can use StaBil, OMC gas treatment, or one of the others. But in any case gas doesn't go bad anywhere near that fast.

I am wondering if anyone has any other ideas on what it could be before I bring it in the mechanics to have the carbs rebuilt.

Check the basics. Do a compression test. Buy a variable gap spark tester (around $10 or so at any auto parts store), set the gap to 7/16" and check the spark on each cylinder. Do a cylinder drop test where you pull the plug wire off one cylinder at a time to see if there's an equal drop in rpm. Visually inspect the spark plugs, do they all look the same or is one significantly cleaner (or dirtier) than the others?

What should I do before bringing in to rule out any other problems?
Would it too hard of a job to do myself. Should I order the manual and give it a go?

A factory manual is always handy to have. Stay away from the generic 3rd party manuals, go with a genuine Evinrude/Johnson manual. You can usually find them on ebay. Most of the time someone with decent mechanical skill can do nearly all maintenance on an outboard engine.

 

[Bob_VT]

Hmmm refurbished impeller - that's a new one on my - I have never heard of one?????

Never use starting fluid on a two stroke since it has zero lubrication and could damage the motor

You never stated what other maintenance had been done. When was the last time the carbs were done completely?

That motor will use 8-9 gallons per hour at wide open throttle and the V-4 motor are notorious for being thirsty.

I would start by getting a manual and do so systematic trouble shooting. All of the maintenance on a V-4 can be intimidating to do the first time then every other time it gets easier. The carbs can be a chore and if you are not comfortable or experienced with carbs I would recommend you get help.

 

[Scott Danforth]

welcome aboard

on-line manuals can be found via the stickies at the top of the forums.

sound like a fuel system issue. time to start diagnosing

regarding the fuel. you state it sat for 30 days since last ran. you did not state how old the fuel is.