85 hp evinrude starts but won't stay idling

pooz · #1 August 17th, 2003, 04:04 PM

First time at this forum - appreciate any help

I have a 1980 85hp evinrude - was running great just a few weeks ago. Now, it starts fine when I use the idle lever, will rev up to 4500rpm, but dies when I bring the idle lever down to normal "run" position. I tried pushing the idle lever down quickly and putting it into gear before it died and it stayed running, but won't get any power - stays below 2000rpm at full throttle. It seems like it starving for gas or "sucking air". I changed gas, gas lines, fuel filter screens, etc. No Luck. This motor runs too strong to be put out of commission because of a bad idle problem. Any Help?

Solittle · #2 August 17th, 2003, 06:25 PM

You might try squirting some pre mix directly into the carbs when it starts to die. If it perks up:

http://www.outboardrepairs.com/carburetors/

The Marine Doctor · #3 August 17th, 2003, 06:27 PM

If there is an "Air leak" problem...the spark plugs with be a dry tan/white.

I would suspect that something has plugged up one of the low speed jets.

Time to remove the carbs and get them fixed up.

A way to check for this....press the choke as the engine starts to die...this will tell you if its a lean condition.

TMD

pooz · #4 August 18th, 2003, 11:24 AM

Marine doctor - thanks for the tip - but it seems to me to run too rich - not lean. smokes, gas on the water around the motor, etc. Someone told me about a rubber diaphragm behind the fuel filter- if it tears, it won't run right. Any thoughts?

Also, if the carbs are dirty - does it happen that suddenly? like I said, motor ran terrific last time I took it out a few weeks ago.

Another piece of info - after I ran it a few eeks ago -it went into the shop for repair. Power trim ram was leaking fluid. Got two used rams put in and no more leak, but now motor is messed up. Could the shop have bumped something under the hood that would make the motor run bad?

The Marine Doctor · #5 August 18th, 2003, 11:28 AM

Do a compression test and spark check on the engine.

Them get back to us.

TMD

dulind · #6 August 18th, 2003, 06:50 PM

the last suggestion of the spark test is a great one, i was having an identical problem with my 135hp due to a bad sensor coil shutting down two cylinders.

pooz · #7 August 19th, 2003, 01:32 PM

Marine doctor - thanks for the suggestion. When you say do a spark check, do you mean just grounding the plug and cranking the motor to see if it sparks, or is there a more involved test that I'm not aware of. Thanks