1990 Evinrude technical advice...please

[Senior Citizen]

Model E70TLESB

Have had motor since 1991, bought new. Has not had the crap run out of it and been pretty well taken care of.

After motor runs at about 2/3 or better throttle for a while it starts to stutter or break down. I can push in the key for the electric choke and it will sometimes get the engine to gain a little rpms, but not back to a steady throttle. At first that made me think fuel problem. Bought a new plastic tank and installed 2 inline filters. Same problem.

SO I'm thinking fuel pump? After the engine sits for several hours (cools down during the sitting) it will crank and run fine unitl it warms up or gets to a normal temp.

Talked to a fellow yesterday that reportedly used to work for a local well known dealership. Guy says it is in the ignition and probably a/all coils breaking down when they get hot, or the power pack or the stator. I'd sure like to narrow it down before I start buying non-refundable electrical parts at astromomical prices.

Says that by choking it, it starves the air and allows the spark ignite the gas, but not hot enough to bring it back up to normal combustion.

Any thoughts?

thanks in advance...
SC

 

[DeadAye]

Any thoughts?

Do you run ALL of the gas out of it EVERY time you finish using it.
If not - Probably the carb jets are fouled.

 

[Senior Citizen]

Do you run ALL of the gas out of it EVERY time you finish using it.
If not - Probably the carb jets are fouled.

XXXXXXXXXXXXXXXX

No, it rarely sits for more than a week or 10 days without being run if only on a hose. I keep Sea Foam and other expensive addatives in it and my 250 HPDI. So I don't think it's bad gas or jets. It will run up to almost 5800 and push my little 16 footer at 56 mph for about 2 minutes and then she collapses (sp). It is definitely temperature related. Either internal or external. Think I might pull the cover off today run her and see if the air passing over the coils and power pack let it run any better/longer.

Thanks for the opinion though.

SC

 

[norm]

I dont believe it is electrical. I would suggest a careful check of the fuel line including the primer bulb. Be especially critical of the primer bulb.

 

[Lee in Quartzsite]

Is it a 2 or 4 stroke? I have a '87 2 stroke and I add oil to the gas. Most all gas now has ethanol in the gas and this has been causing havoc in the boating industry. I use 6 gallon metal tanks and have found that if I let the gas sit for over a month or so it forms small sticky balls of goo in the bottom of the tank. These have clogged my fuel lines and filter twice in the last 6 months, causing my engine to lose power. If you have a built in tank made of fiberglas it causes even worse problems. Do a Google/Yahoo search on ethanol gas in boats, or search BoatUS web site:

BoatUS.com

 

[Senior Citizen]

I dont believe it is electrical. I would suggest a careful check of the fuel line including the primer bulb. Be especially critical of the primer bulb.

xxxxxxxxxxxx

Tried that. When it shuts down I check the bulb and it is still fairly tight. Can squeeze about a half squeeze and it's hard again. Try to crank and run it again and it does the same thing until it cools. Swapped lines with my brother's motor for a day. Same thing. I've cleaned the motor several times and dried it. I always keep a look for leaks and find none. Gonna buy a new fuel line assy and 3 new plugs today and run it this evening.

my thoughts about the coils.........Would all three break down at the same time? Don't think they would. But if one fails that would/could be enough power loss to make the engine run bad. (33% power loss) I'm thinking power pack is failing because of heat.

Will let you know how this pans out.

thanks again for all suggestions.

SC

 

[Rule3]

Oh If I only had $1 for every time this happened to me and with several different motors/boats

I have had it be both and diagnostics is a pain. I am going to just guess : Stator or coil/power packs

Will drive you crazy!

Sorry for your troubles and good luck!

 

[Pop's2]

from a similar past experience........coil or power pack; in my case it was coil only.

 

[ohiobuckeye]

My buddy had similar symptons that persisted through carb cleanings, fuel pump replacement, one coil replaced(that gave a slight improvement) and was finally repaired when all three coils were replaced. All work was done by a reputable dealer and I had a hard time believing all three coils would go bad at once but individual examination and testing of the coils showed they were defective. Good thing marine engine parts are cheap...

 

[Rule3]

I think we have narrowed it down. Its either electrical, mechanical or fuel related.

Have you checked the radiator

I still think it's stator/power pack.

The most baffling problem I ever had was on a old Evinrude 60. It would run fine at top speed and then start cutting out and then go again. Very similar to what is happening to you. Could not figure it out. Then one time will running I took of the cover and there was a little perforation in the water jacket (salt water corrosion) and it was spraying a little stream of water on the electronics and shorting it out. Patched it with J B weld and sold that puppy in a hurry. Never bought another OMC product again.

 

[Senior Citizen]

I think we have narrowed it down. Its either electrical, mechanical or fuel related.

Have you checked the radiator

I still think it's stator/power pack.

QUOTE]

XXXXXXXX

Radiator is "pee'ing" great, I mean for "its" age!

I was hoping I could chalk yet another malfuntion up to operator headspace or loose adjusting nut....................but I can't.

Got another fuel line with bulb and new plugs this morning at West Marine. Remember when just about any old plug would fit your 3HP Briggs & Stratton or your Z-28................

Gonna back the throttle stop back out of it to the factory setting, pull the cowling off, ease up the river about 4 miles, turn my hat around backwards, hook the kill swith around my neck, lean forward and stick it to it! When she hits 5300 I'm gonna start lifiting the jack plate and the trim till she blows a rooster tail up about 10-12 feet and hits 5900. She's gonna run or swim home. I hope my trolling motor still works!

PS: Honey, leave the back porch light on and don't wait up.;-)

Power Pack $153.00
ignition coil 33.60 X 3
stator 283.80

 

[Rule3]

If it runs at top end at your "regular" top tach rpm depending on your prop and then starts cutting in and out and dropping speed than going back to top end I'd bet it's one of those there electronic things. That's what another engine I had did.

Good luck, I hope it's something simple and cheap like maybe just a coil.

 

[Strato]

I would think if it was an ignition problem, dumping more fuel via the choke(actually a primer) would be more apt to flood it rather than help it recover. It almost sounds like something you never hear of anymore. Vaporlock. Remember the old wooden clothespin trick? It's doubtful but it's the cheapest test.

 

[SWID]

I have a 2 cycle weed eater that does sort of the same thing. Runs well until it gets hot then quits. The shop diagnosed it as the ignition and said buy a new weedeater as it would be almost $100.00 for parts and labor. This man does not sell new stuff and he spent a half hour on it and charged me nothing. I know that outboard motors cost more than weed eaters but from what you say I would guess ignition.

 

[Senior Citizen]

If it runs at top end at your "regular" top tach rpm depending on your prop and then starts cutting in and out and dropping speed than going back to top end I'd bet it's one of those there electronic things. That's what another engine I had did.

Good luck, I hope it's something simple and cheap like maybe just a coil.

XXXXXXXXXX

Basically, all my toys have 2 speeds. Wide open and Stop.

Seriously though, I'm pretty easy on my stuff. But sometimes I like to feel the wind in my hair.

Motor has been doing this since last year around Thanksgiving. Not as bad as now, but not sure if it was because it was a lot cooler then or the problem is getting worse. Probably a little of both. To keep myself from running her up on just the cavitation plate and wide open I turned the throttle stop down to about 4400. That keeps me from running so hard, but she still will shut down at that rpm range after 4 or 5 minutes. Once I get up on plane I usually run under 4000. It's a light boat and has a 27 pitch prop on it. (boat is rated for 40 HP)

Not gonna be able to test her this afternoon. Storm(s) have rolled in and looks like here to stay for a couple of hours. Maybe Thursday morning.


Thanks again for all the ideas and suggestions. Think I'm going to go ahead and order 3 coils in the morning and work my way up to a new 90 horse Yamaha or E-Tech.

SC

 

[tacreload]

Did you look at or try new spark plugs?

 

[Senior Citizen]

Did you look at or try new spark plugs?

XXXXXXXXXXX

I've been through several sets of Champion QL77JC4's and 1 set of NGK BZ7HS-10's. Put new NGK's in this morning. Old champions weren't over 2 months old and looked good. Will keep them and have them cleaned. They are $7 each.

Ordered 3 coils for $25.41 each a few minutes ago. That's cheaper than having a mechanic just lift the hood and look at it.

SC

 

[Grayfox]

Could very well be bad ignition parts. I see this same sort of problem in small gas engines quite often. That's all an outboard motor really is.
Just like you said, once they get hot the coils start breaking down. Considering its age, I'd go ahead and replace all the coils and plug wires.

 

[dragonslayer808]

This may sound a little strange, but if there is any way you could set an ice pack on your ignition module while the motor is running it will keep the pack from over heating. This is a way we use to tell the problem on old ford ignition packs, if they kept running after the engine got warmed up then that was the problem.

 

[VinnieL]

I'm curious as to the outcome of this problem.