need help with 140 looper

1slowcamaro

Cadet
Joined
Jul 29, 2012
Messages
13
I just recently picked up a 1985 140 evinrude and threw it on my little ski boat. this motor had sat for a while before i got it. it surges at wot and spits and sputters and dies at idle. it seems a little low on power. it only pushes my 15 foot ski boat at 44mph with a 19 pitch prop. compression checks out good vro has been replaced with a normal pump and i have changed all of the fuel lines. where do i need to go next
 

nphilbro

Petty Officer 1st Class
Joined
Dec 19, 2011
Messages
304
Re: need help with 140 looper

As they always say- what's the compression and what's the spark (7/16 gap jump) on each plug?

I had a 1980 140 on my big boat and it pushed me to over 41mph so something is amiss. In fact, I'd be concerned that's way too much motor for that boat.

Sounds like timing to me. If you are getting pre-ignition you can kiss that motor good-bye so you'll want to do a link and sync before you take it out again.

Could be carb too - a lot to check out on a new motor.
 

monnewbie3

Petty Officer 3rd Class
Joined
Sep 12, 2011
Messages
90
Re: need help with 140 looper

I gotta 78 140 rude. Sounds like how it ran when I got mine.

Your timing is off, guaranteed.
Once you get that in check let us know how it's running :)

Oh and don't run your motor like that.. It'll toast it. Read up on how to do timing and link and sync... Or just pay a mechnic for a few hours and get him to do it...

My 17.5 foot glass bow rider does 43mph with a prop that needs to be replaced lol
 

1slowcamaro

Cadet
Joined
Jul 29, 2012
Messages
13
Re: need help with 140 looper

Compression is exactly 120 across the board. i have been idling it up using the shifter cable is this the correct way?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,041
Re: need help with 140 looper

First things first!!
Comp good!! Good spark???Get a tester that measures the gap(npilbro) weak spark ??
Then check for water in the fuel.
Clean the carbs.Anytime a boat sets for a time they should be cleaned.
They have lots of crooks and hidy holes so do a thourough job.
Then rebuild the fuel pump.

Speed??? You have a tach?
What RPM's at WOT?
I believe that motor should be about 5500 WOT.
Do these things and get back.
 

1slowcamaro

Cadet
Joined
Jul 29, 2012
Messages
13
Re: need help with 140 looper

Fuel pump is new.
spark jumps a 7/16 gap
fuel lines and tank are new
fuel is clean
carbs are spotless

i don't have a tach
now it has different symptoms since i have been messing with it
i can idle it up high enough to make it idle but randomly its like the motor stops firing . everything goes quiet and all of the sudden it wakes back up. now when you give it any throttle it just breaks up really bad
 

monnewbie3

Petty Officer 3rd Class
Joined
Sep 12, 2011
Messages
90
Re: need help with 140 looper

Still think it sounds like timing.

You'll need something called a timing light, you usually hook it up to the number 1 cylinder (should be marked, and is usually the highest of the 4) and check the timing on the flywheel or timing window (flywheel in this case I believe).
Check the forums on the exact procedure, I believe there's 2 different ways.

If you're sure the carbs are clean, good fuel, and electrical is good, I would spend the 60$ on a timing light or get a buddy to come by with one.

Cheers,
 
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