Engine quits when throttle advanced

[Kettler]

Happy summer everyone, Been out on the boat once a week or so since May hope you have done the same.

I run an 1986 evinrude 40 hp on a 15' Hobie Power Skiff and was out in the ocean today running full tilt for a mile or so.

I throttled back down to 6 mph for a few then throttled back up, started to plane and the engine quit.

Checked the vent on the fuel cap was open, Squeezed the bulb,primed and choked and finally the engine turned over and was able to come in with the throttle not much above nuetral

Tried again same thing but didn't quite get the boat to plane. (she flattens right out)

I was thinking fuel pump and squeezed the bulb a few pumps all the way back. Bulb seem to be hard but not rock hard.

Got back to the cove and stopped pumping and cruised slowly around for 3-4 min. then when I advanced the throttle a bit the engine quit.

Any ideas?

 

[Kettler]

Re: Engine quits when throttle advanced

Wow 15 views and no replies whats up with that?

i thought we were a community??

 

[HighTrim]

Re: Engine quits when throttle advanced

Just be patient, ppl will come along to help.

When were the carbs last rebuilt? May be time for a bath and rebuild. Also check to see if the timer base (starboard side, under the edge of the flywheel, linked to the throttle lever) moves smoothly without sticking when you advance the throttle.

Take the airbox cover off & observe whether the throttle plates are parallel.

Also, the timer base should start it's travel *before* the throttle plates start to open, else she'll fall flat when you try to accelerate.

 

[noelm]

Re: Engine quits when throttle advanced

there is a couple of possibilities here, lets start with the no cost, non invasive first, can you try a complete new tank/hose and fuel? check to make sure the timer assy moves when the throttle is advanced, pull the plugs and have a look at them and let us know their appearance, is it a rope start? if so do you feel compression when pulling it over? does it make any bad noises when running? try those things, then get back to us, do not start pulling things to bits yet, you may end up with a new and unknown problem.

 

[jtexas]

Re: Engine quits when throttle advanced

also, inspect the wiring coming off the stator & timer base. look for chafed/missing/burned insulation. Look for a bare wire contacting the engine block or otherwise grounding out.

Sounds almost like the ignition is being shorted.

 

[Evinrude Boater]

Re: Engine quits when throttle advanced

My 75hp did a similar thing and I found a piece of something in the high speed jet. It has two carbs so the other side kept it going but fouled the plugs since I was trying to push it to accelerate. I thought it was ignition related too. It probably ran at an idle because the slow speed jets are fine. Check it out, it's free.

 

[Kettler]

Re: Engine quits when throttle advanced

Thanks I'd given up.

Pulled plugs #2 fouled w/oil......... replaced plugs.....started ok and tooled around the harbor for about 2 min. then engine died.

Checked plugs both were clean.

Will check compression and spark next chance i get.

Thanks

 

[CharlieB]

Re: Engine quits when throttle advanced

Chances are you sucked up some crap from the fuel tank, the carbs need to be opened and cleaned out, or at least drain the float bowls and pull and clean the main jets.

 

[Kettler]

Re: Engine quits when throttle advanced

Thanks for the input on my 1985 evinrude 40hp

I have Good Compression and good spark.

I have Visually inspected everything.

I have rebuilt the Carbs and went through the entire fuel system on the engine (twice).Everything ship shape.

I bought a new 6. gal. fuel tank and have new gas / oil mix as I really had suspected water in the fuel.(VRO removed and replaced with Pump P/N 438559 last year and ran well)

Started on muffs fine. Launched in the bay and tooled around a bit

Advanced throttle a few times seemed ok headed out and ran for about 5 min. 4- 6mph then she died.

Tried to restart her pumped the bulb a few times and primed but engine would not start. Towed back in

Could the check valves in the bulb be the problem? I have tested them and they seem to hold.

If it was running for five mins. can I rule out the fuel pump?

What next?

Compression,spark, fuel, runs then shuts down. HMMMMMMMMMMM

 

[jtexas]

Re: Engine quits when throttle advanced

"Tried to restart her pumped the bulb a few times "

If the bulb wasn't firm when the engine died, then the fuel line's not holding pressure. You should only have to pump it for the first start of the day.

Possibilities: sucking air at a fitting, faulty primer bulb. Carb float valves leaking - that would also flood the engine, shutting it off. Could also be fuel pump.

Pump up the fuel line, tilt the engine full up, observe whether any gas runs out the carb throats when you squeeze the bulb, if so try readjusting the float heights.

"Compression,spark, fuel" -- but "not too much fuel"

 

[mike godfrey]

Re: Engine quits when throttle advanced

i had a simular thing happen to my 70hp evinrude motor. had plenty of spark at plugs, but when i did the spark test it wouldn't jump the 7/16 spark tester changed the coil. and also found a bad wire on rectifier changed that now motor runs great. just an idea

 

[jonesg]

Re: Engine quits when throttle advanced

Wow 15 views and no replies whats up with that?

i thought we were a community??

a community is made up of different types ,a few none experts like me.


at least you know a lot of others are following your saga.
We're just not capable of helping.

 

[Kettler]

Re: Engine quits when throttle advanced

I think were on the same page thanks for the tips especially about the floats.

I am still leaning towards fuel. I'll try the test.

Can you help me with the rebuild kit number for my fuel pump Part # 438559?

When I rebuilt the carbs my float adjustment, measured from the top of the gasket, was 1/16" level and with the float hanging and holding the gasket in place the float hangs 3/4" from the top of the gasket right?

Last year I was in the same position and replaced the powerpack and was off boating but am really trying to hold off on that though, no sense in just throwing parts at it. I will retest the spark again.

Thanks for the input. Stripers will be back soon.

 

[Kettler]

Re: Engine quits when throttle advanced

Here's the update

Installed new bulb in line.

Did recommended test for the carbs and no fuel in the barrells of the carbs when squeezing the bulb and engine tilted up.

Maintained pressure on the bulb check for fuel leaks in hoses etc. All tight.

Installed new on gaskets on air silencer cover and between carbs and silencer body. (The ones I had were pretty beat up.)

Attached muffs, put lower unit in tub, I use a large square rubbermade storage container up on blocks, the lower unit fits in nicely even with the muffs on.I highly recomend it.

Engine started with one turn of the key and warm-up lever down.

Ran in the tub 15 min. while I threw dinner on the grill, advanced the throttle just enough to spin the prop and for only about ten seconds under 1500 rpm every few minutes, three times.

Shut her down and checked for leaks. All tight. fired her back up a few minutes then ate a late dinner.So hopefully an early launch to see how we did. Thanks for everyones interest !!!!!!!!!!!!

Question though, As the engine was running the bulb was firm but not hard sound right?

I can't remember back when I was on the water alot how it should be.

Fish On

 

[Kettler]

Re: Engine quits when throttle advanced

Primer Bulb: $10

Gaskets: $10

My Time: "Free"

Everyones Help: Priceless !!!!

First 20 mins. I spent in an ever widening circle staying within rowing distance of the ramp.

Throttled up a bunch, back to neutral etc. General tooling around.

Bulb stayed firm. Engine sounded a little rough.Do I need to do link and sync? or have I been lucky to date? Anyways......

10 mins. to the ski area and then just opened it up and it was off to the races. Throttled back a few times and then back to full tilt.

30+ mins. later low on fuel and headed back.

Back in the driveway washed her down and did inspection of the engine, hoses, wires etc. All secure.

Went and got more fuel $3.95 a gallon

Thanks to all and Fish On


I'll go to FAQ to learn more about the link and sync