1981 Evinrude 140 V4 Problems

Hunt140

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Hey guys this is my first post here. I just bought a 1974 Sportcraft Sportsman 200 with a 1981 Evinrude 140 on it. The boat is in great shape and the motor only have maybe four good years of running on it.

I took the carbs off and cleaned them throughly and put them back on. Then i fired her up and it ran great an idled great after a little adjusting. I then did a de carb with seafoam and everything was good. Idled great and i revved it up a couple of times and no problems.

Went and dropped her in the water yesterday and it started right up. it was idling around 800 so i adjusted it right at the dock to about 1000. Put it in gear and headed out just running about 1000. I got out into the main channel and went to give it some throttle and it got to 1200 and then just died. Started right back up and same problem so i turned around and at the same time the overheating buzzer went off. I went towards the dock for about another 100 yds and the buzzer kept going so i figured i would stop and fish while i was out on the water. I fished for a hour or so and went to start her back up and had a very hard time. I had to keep priming it and messing with the choke/throttle until it finally kept running at about 1400. I had to let it run for 2 or 3 minutes until it would finally idle and go into gear again. I didn't get anywhere and the buzzer went off again, couldn't go past 1200 so i limped back to the dock. Shut it off went and backed my truck in and then went to start it up to put it on the trailer, nothing. I messed with it for 10 minutes and it wouldnt stay running, the battery was dead by then so i walked it onto the trailer.

Sorry for the long post but im trying to give as much info as possible. I know the thermo's definatly need to be replaced thats why it was overheating and buzzing but what about the hard starting and not going over 1200? Is there a safe mode on this motor or what? Also, the water pump is brand new and has a great stream of water.

Thanks for any help i can get.
 

ezeke

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Re: 1981 Evinrude 140 V4 Problems

There are three components on the cooling system that need checking: the water pump, the thermostats, and the water passage deflectors, in that order.

When the engine overheats and sounds the alarm, damage is usually already done if you don't shut it down immediately. You may have a blown head gasket or worse.

You should assume that the head gasket is bad and oil the cylinders as soon as you can.

You will need to drop the lower unit to see what you need in the water pump. You will need a thermostat kit to service the thermostats, and you will need two cylinder head gaskets to check those and service the deflectors.

You will also need a reliable torque wrench.
 

Hunt140

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Re: 1981 Evinrude 140 V4 Problems

Pump is good. Thermos are definatly getting replaced. I will pull the heads tommorow and check the cylinders.
 

Bob_VT

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Re: 1981 Evinrude 140 V4 Problems

If you are pulling the heads then change the water deflectors.

Take it from a person that just installed Thermo's, deflectors, water pump and head gaskets............

Be real careful with the thermostats..... they are a PITA and the water hoses that connect to the heads (oh yeah replaced those too ).

In for a penny....in for a pound....... I would also do the impellar.
 

Hunt140

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Re: 1981 Evinrude 140 V4 Problems

Ok thanks Bob. Any tips/tricks for the deflectors?

Do you think the overheating problem is related to not going past 1200 or is that a seperate carb or electrical problem?
 

emdsapmgr

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Re: 1981 Evinrude 140 V4 Problems

If the engine overheated it is probable the pistons expanded in the cylinders, causing extra friction and running problems. Enough of an overheat and the piston expansion will actually cause them to stick/stop inside the cylinder walls. Follow ezeke's recommendations.
 

ezeke

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Re: 1981 Evinrude 140 V4 Problems

I've added some pictures of what happens when deflectors get out of place.

Once they block the water passage the cylinder quickly overheats and the steel liner separates. After that the block may be useless. Sometimes the piston just binds enough to snag a ring and score the cylinder.

The diagram shows the correct position of the deflectors and the normal flow of water is indicated by the small arrows in the passages.

You can remove the deflectors with needle nosed pliers and push new ones into place by hand. Trim them flush with a single edged razor blade.

The deflectors are basically pieces of 3/8 inch fuel line with an ID of 1/8" or less.
 

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Rscardina

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Re: 1981 Evinrude 140 V4 Problems

wow those are some clogged passages... question.. if your tell tale is strong does that eliminate this probability or can water still get around and bypass an area and still appear that the pasages are clear based on good flow?
 

ezeke

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Re: 1981 Evinrude 140 V4 Problems

Because you can have no flow in the cooling passages and still have good flow from the tell tale, that is of no value as an indicator other than to let you know that the water pump is functional.

In other words, you can have good steady flow from a tell tale while the thermostats are totally blocking the flow of water through the cooling passages.

The temperature switches and horn connected to them are the only reliable stock indicators. Adding temperature gauges gives you a heads up, but you need them for both banks of cylinders to be really effective.
 

Rscardina

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Re: 1981 Evinrude 140 V4 Problems

Because you can have no flow in the cooling passages and still have good flow from the tell tale, that is of no value as an indicator other than to let you know that the water pump is functional.

The temperature switches and horn connected to them are the only reliable stock indicators. Adding temperature gauges gives you a heads up, but you need them for both banks of cylinders to be really effective.

well sir..thanks for the heads up.. i was under the impression tell tale told you you had flow and I assumed the flow had direction so as to indicate that passages were clear....never assume is the lesson here i guess..

I may pull my heads to check after seeing that crud in there...for the cost of a couple of head gaskets its well worth the investment...stats as well..

Thanks!
 

Hunt140

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Re: 1981 Evinrude 140 V4 Problems

That explains the motor not wanting to start. I'll be pulling the heads tommorow and hope for the best.
 

Hunt140

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Re: 1981 Evinrude 140 V4 Problems

Well I got the heads, exhaust and thermo covers off. Took me three hours to get it all apart and snapped 2 bolts that the salt water had got too. The first owner used it out in the bay and it has sat mostly since then so the salt has really built up and blocked everything.

The cylinders look good. There is still cross hatching in them actually. The thermo cover was full of sand because it was never flushed after being used. I will clean all of the water ports, replace the deflectors, new thermos, new hoses and all new gaskets. Is there anything else I should do?
 

ezeke

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Re: 1981 Evinrude 140 V4 Problems

You might want to check the water intake screen below the water pump to see that it is in good condition.
 

Hunt140

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Re: 1981 Evinrude 140 V4 Problems

Thanks ezeke, i did check the screen and its good. These bubble backs are a P.I.T.A to work on. I didn't even try to take the thermo cover off until i took the exhaust covers off and it was still a pain. Gotta love it i guess.
 

emdsapmgr

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Re: 1981 Evinrude 140 V4 Problems

I'd pull the head covers off and inspect for any debris there also. What you find in there will be indicative of what is in the rest of the engine. If it's bad, you might want to pull the water passage cover off the top of the block and have a look inside. The gaskets are cheap.
 

Hunt140

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Re: 1981 Evinrude 140 V4 Problems

What do you mean by water passage covers? I have the head covers off along with the heads.
 

tal

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Re: 1981 Evinrude 140 V4 Problems

Sounds like the funnest part will be getting the snapped bolts out.
 

ezeke

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Re: 1981 Evinrude 140 V4 Problems

The crossflow engines have a core water passage running up the center of the block. It's under the lifting eye on the 1981 block. You will need a gasket if you open it up.
 

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Hunt140

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Re: 1981 Evinrude 140 V4 Problems

Well one of the bolts was the middle bolt on the thermo cover that broke. I sprayed some PB Blaster on it and it can out pretty easy with vise grips. The other one is one of the head cover bolts that is in the head but there is a good half inch for me to grab with the vise grips and that is soaking right now.

Okay thanks ezeke. Can I get that off with the flywheel on?
 
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