70 hp cutting out problem

jtexas

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Re: 70 hp cutting out problem

hmmm.... the "EE" in your model number E70PLEEA translates into 1999, and the first E means "Evinrude" (to distinguish it from Johnson). The 1999 rude 70's were fuel injection; your picture looks similar to the Johnson carbs from that year, but a different part number. I can't find your part numbers. I don't know about any '03-'04 carbed 3-cylinders. Before '99 or so, Johnson & Evinrude models were mirrors of each other, interchangeable part for part.

The 3-cylinder carbed johnnyrudes came with different carbs over the years; some have adjustable slow speed jets, others are fixed. Some have 3 jets, others have two.

"All three valves are connected by a bar, so if one sticks would it hold the other two open with it." Yes, should have known...but somehow I had in mind that one of yours was out of sync.

If the motor's running without a load (in neutral and especially on the muffs) and all three throttle valves are open, it'll race, RPMs would be sky high; so that's not happening.

Sounds like your mechanic adjusted the "pick-up timing". when you push the throttle control forward, after it shifts into gear, the spark timing has to advance before the carb throttles start to open; if the carbs open too soon, the motor will just die on you. He might have called it an "idle adjustment" cause it's easier than trying to explain syncronization to a customer. Sounds like he was headed in the right direction, but he should have put it in the test tank with a test wheel and made sure it would run right before turning it back over to you.

You get the same result if the idle speed is set too low. But either way, you're more likely to be able to nurse it up to speed by feathering the throttle, instead of putting the hammer down quickly. That's been my experience.
 

wahoo 16

Cadet
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May 30, 2008
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Re: 70 hp cutting out problem

hey there, lots of good suggestions. my experience would tell me to clean them carbs. very important to pop the tin covers and clean the intermediate fuel circuit passages. just my humble advice
 

landyman

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Mar 25, 2007
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Re: 70 hp cutting out problem

the lifeboat institute here in the ireland and the uk purchased a big batch of 3cyl evinrudes in about 1998/1999 and mothballed them so that they would have a supply of engines for at least 5 years. they knew that the newer engines were going to be fuel injected and that they couldnt be converted to a suitable spec for themselves.( ie very simple mechanics) they have now started to phase out the evinrudes and have gone to the 75hp yamaha, again still a carbed motor. however a lot of the lifeboat mechanics and coxwains still reckon that the evinrudes were far superior to the yamaha's. the other difference is that the transom clamps/trim tilt unit appears to be off the larger V4 type engines.
 

jtexas

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Re: 70 hp cutting out problem

A supply of engines for 5 years ...... boat motors that run upside down and submerged ....... is it just me, or does anybody else think that's just really, really, awesome cool?
 
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Re: 70 hp cutting out problem

One other thing to check: make sure the timer base is moving smoothly without sticking when you advance the throttle. (see pic)


When I push the throttle lever forward while watching the timer base I noticed that the lever is nearly halfway to the full throttle position before timer base moves. Is this right?
 
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Re: 70 hp cutting out problem

its to do with the idle screw settings being out slightly. its idling a little lean so when it comes off the idle circuit and on to the slow speed jets it cuts out. thats a common enough problem on them. did you try choking the engine when you give it throttle?

(galwegian meself)



How do I go about changing the idle mixture to a slightly less lean mix to see if this helps



Also I never have this cutting out problem when engine is on the muffs. It's only when in the water?
 

jtexas

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Re: 70 hp cutting out problem

When I push the throttle lever forward while watching the timer base I noticed that the lever is nearly halfway to the full throttle position before timer base moves. Is this right?

sounds about right, but % of throttle control travel is not a good way to evaluate it; some of that travel is needed for shifting.

Look back the pic I posted -- when the cam hits the roller, the throttle valves open. So, after it shifts into gear, but before the cam hits the roller, the timer base should be advancing.

The cam has to hit the roller right on that mark. If it hits too soon, RPMs start increasing before the spark is advanced enough, so it's like the spark is chasing a retreating piston; you get no benefit from the fuel burn.

On the muffs, the motor is completely unloaded, so spark advance is just not very important. On the muffs that motor will run all day on 2 cylinders and sound perfectly happy doing it.

Step-by-step idle screw adjustments:
http://forums.iboats.com/showthread.php?t=167352
 
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Re: 70 hp cutting out problem

Hi again jtexas, Thanks for your replies to date. I have been away so I haven't had much time to look at the engine until now.

As you suggested I have looked and the throttle vales are opening before the timer base begins moving. It is not actually close, the valves are well open when the timer base moves.
 
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Re: 70 hp cutting out problem

--------------------------------------------------------------------------------

Hi again jtexas, Thanks for your replies to date. I have been away so I haven't had much time to look at the engine until now.

As you suggested I have looked and the throttle vales are opening before the timer base begins moving. It is not actually close, the valves are well open when the timer base moves.
 
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Re: 70 hp cutting out problem

Due to holidays etc. Today was my first time out since I made the adjustments to the engine to ensure the timer base move before the valves opened.

The engine ran perfectly, so that was my problem.

Thanks again to jtexas, landyman and all other replies. I am delighted with how it ran today
 

jtexas

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Re: 70 hp cutting out problem

awsome, thanks for the update!
 
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