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1991 Evinrude 70HP Problems

R

Redrobinyum3

Member
Hello,
I recently purchased an Evinrude E70TLEIE 70HP and have been having several issues with it. I brought it out on the water twice this weekend to give it a test run, see how it would work under load and try and troubleshoot and identify any issues/problems. This is the problems I've been having as of now are;

1: The engine starts up and idles but I have to keep the throttle open a bit to keep it idling, if I put the throttle all the way off it will begin to slow down and stall. Even when in gear under load it will stall at low speeds. Sometimes the engine will start right back up and other times it takes several try's.

2: While running at low speeds it stops pissing and steam will come out of the hose, put when I give it more gas the water will start flowing again. Whenever I would notice the steam I would increase the throttle to get the water flowing again and not let it overheat. I replaced the water impeller and it seems to have made no difference if not worse, but that was tested with muffs

3: For the majority of the time the engine was definitely not producing its full power, even at full throttle. For a brief period of time it seemed to be running at its full potential but after I pulled back on the throttle when I would try to give it more gas the motor would sputter and lunge forcing be to pull way back on the throttle. After restarting the engine it was back to the same issue of not producing full power.

4: After getting it home I noticed that the Timing Base is sticking and will not move unless I force it to.

I have already done the following to the motor, before the test run
Checked the compression and everything was all good
New Spark plugs
Thoroughly cleaned the Carburetors
New Battery

I replaced the water impeller after the test run but it didn't seem to make any improvements.

I'm running 50:1 with fresh gas and have bypassed the VRO and mixing in the fuel tank. It is on a 17' Fiberglass Runabout

Any ideas, advice or solutions would be very much appreciated.

Thank you,
 
What are the actual compression numbers today ?----Post them.-------Does the pisser hose come off the side of the block or off the top ?----The latest water pump kit comes with parts / instructions for cooling system modifications.
 
racerone said:
What are the actual compression numbers today ?----Post them.-------Does the pisser hose come off the side of the block or off the top ?----The latest water pump kit comes with parts / instructions for cooling system modifications.
Click to expand...

Ill check the numbers tonight.
The hose comes off the side
 
Could be a bad thermostat too. New ones are 12 bucks on line. I use them and they are good. The linkage components on starboard side may need to be dismantled, cleaned with gas.....all aluminum wear sludge removed, then re lubed with fresh high quality grease. This is often overlooked. What happens next is stiff operation of throttle. Do not force it.....clean it.
 
timguy said:
Could be a bad thermostat too. New ones are 12 bucks on line. I use them and they are good. The linkage components on starboard side may need to be dismantled, cleaned with gas.....all aluminum wear sludge removed, then re lubed with fresh high quality grease. This is often overlooked. What happens next is stiff operation of throttle. Do not force it.....clean it.
Click to expand...

Okay, I'll give that a try and see what happens.
 
The thermostat has nothing to do with the pee hole on that motor. You have the plastic thermostat buy a decent one its cheap insurance. Where did you get the impeller from? 3 vane or 6 vane? Did you use the correct key? Did you use a key at all? Is the peehole tube itself plugged? Have you tried taking the hose off and seeing if it is plugged? How did you push on the timer base? Did you try moving the whole assembly with the cable attached? Or did you move the part under the flywheel only?
 
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Right I agree, but only buy the good Sierra thermo or better. I stock up on them, will include a screenshot here. FYI. Could be thermo is sticking and causing overheat, but as you state....likely lack of water flow at low speed. Have also seen where head gasket will leak and invite compression gas into the cooling jacket. May notice then, a difference in the spark plug on affected cylinder......might not show up on compression test. The incorrect pressure at the head gasket leak will disrupt circulation causing hot spot, air.....and resulting steam. This one is 25 bucks. But you can find brass ones down to 12 bucks.
 

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flyingscott said:
The thermostat has nothing to do with the pee hole on that motor. You have the plastic thermostat buy a decent one its cheap insurance. Where did you get the impeller from? 3 vane or 6 vane? Did you use the correct key? Did you use a key at all? Is the peehole tube itself plugged? Have you tried taking the hose off and seeing if it is plugged? How did you push on the timer base? Did you try moving the whole assembly with the cable attached? Or did you move the part under the flywheel only?
Click to expand...

The impeller is 6 vane and yes I used the key. I've tried taking off the hose and checked to see if it is blocked up and its all clear. I moved the timer base only at the part under the flywheel. I moved it back and forth by hand and it takes a lot of pressure to move.
 
There was a service bulletin that came out in 1994 to move the pisser hose to the top of the block.-----So in 26 years it was not noticed.----
 
timguy said:
Right I agree, but only buy the good Sierra thermo or better. I stock up on them, will include a screenshot here. FYI. Could be thermo is sticking and causing overheat, but as you state....likely lack of water flow at low speed. Have also seen where head gasket will leak and invite compression gas into the cooling jacket. May notice then, a difference in the spark plug on affected cylinder......might not show up on compression test. The incorrect pressure at the head gasket leak will disrupt circulation causing hot spot, air.....and resulting steam. This one is 25 bucks. But you can find brass ones down to 12 bucks.
Click to expand...
That is not the correct thermostat I did say he had the plastic one. Are you using muffs or a bucket?
 
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Sorry I didn't note the year. Personally I don't like or use plastic thermostats. Just did a 1981. It had a "real" thermostat in it. If something has a plastic one in it, I throw them as far as I can back in the woods behind my shop. Guess I belong in the 1950's. I would love to go back.
 
racerone said:
There was a service bulletin that came out in 1994 to move the pisser hose to the top of the block.-----So in 26 years it was not noticed.----
Click to expand...

I just recently got the engine, I will modify it to relocate it to the top of the block.

Any ideas what could be causing the other issues?
 
Could be a number of things. Need actual compression numbers, as aforementioned. Need to correct problem with stator/timing. This must move smoothly without binding. Make sure head gasket is good. How? Has it been replaced yet? Look for lack of paint on edges and paint chipped off head bolts. Any indication of water on spark plugs? Did you thoroughly clean main jets......were the carbs oxidized with any debris when you inspected and cleaned them? Need answers to these questions. Please. Compression test with all plugs removed and fast cranking speed. If motor is in the water, it may lower numbers......so prop open throttle at carbs to invite unrestricted air for compression.
 
Post your compression test values that it has today.---Flywheel key checked ?-----High speed jets that are in the carb bowls confirmed clean ?----Does spark jump a gap of 7/16" on all 3 leads , yes or no?----Water coming out of the pisser should be relatively cool.-----It does NOT go through the engine.----So steam is a huge concern to me !-----Do not run the engine until you sort this out !
 
I cleaned the carbs to the point that they were medical grade.

It seems like I have multiple issue to address. Should I start with removing the flywheel and find the cause of the Timer Base sticking/resistance and get that moving smoothly before I get into drilling and taping?
 
Redrobinyum3 said:
I cleaned the carbs to the point that they were medical grade.

It seems like I have multiple issue to address. Should I start with removing the flywheel and find the cause of the Timer Base sticking/resistance and get that moving smoothly before I get into drilling and taping?
Click to expand...
Get your cooling issue fixed first. Do the compression test. Then pull the lower unit off and use your hose to put water through the block. Replace your thermostat with the correct one.
 
Redrobinyum3 said:
It moves but not freely, takes a good amount of pressure to move it
Click to expand...
It should only move freely about an inch after that it will be difficult because the linkages are attached. Are the linkages and cables attached? How about that compression test? Get a manual it will give you some direction because you are all over the place.
 
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Guess I'm just old fashioned. If there's a way....I'll make something better, if I can't make it better.....I'll put it together with parts as it was engineered.....and in "Racers" words tell the customer "good luck with your motor"!
 
Okay, agreed, sorry. The timing base should move freely with linkage detached. If it doesn't, then, if the cause is not apparent by looking around beneath the flywheel, the flywheel should be removed. Still have to address the steam problem coming out the pee tube. We need an accurate compression test and perhaps pictures of the spark plugs....if they are used and showing color.
 
Okay, decent numbers. I have seen on these motors that a carb running rich will drag down motor at low speeds, flooding one cylinder. When this happens, it is hard to restart. What commonly causes this is something in the float valve. The affected cylinder will show a rich spark plug. Can you tell us what the plugs look like as far as color and condition.....and is one or two of them appearing rich?
Even the cleanest carbs can be reinfected by something upstream.
Need to find the cause of timing base stickiness.....this could also be the problem, as it hasn't been dealt with.
 
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timguy said:
Okay, decent numbers. I have seen on these motors that a carb running rich will drag down motor at low speeds, flooding one cylinder. When this happens, it is hard to restart. What commonly causes this is something in the float valve. The affected cylinder will show a rich spark plug. Can you tell us what the plugs look like as far as color and condition.....and is one or two of them appearing rich?
Even the cleanest carbs can be reinfected by something upstream.
Need to find the cause of timing base stickiness.....this could also be the problem, as it hasn't been dealt with.
Click to expand...

The spark plugs looked dark but a light coating, nothing gunk'd on when I removed them, I'll do a closer inspection in better lighting tonight, but I also didn't replace/clean them after I cleaned the carbs (I did replace them when I first got the motor though, but ran it before cleaning the carbs). I'm removing the flywheel tonight to inspect the timing base
 
So I pulled the flywheel and took off the timer base. The Retainer base ring (0313666) was deformed, (I'm guessing from heat, so that just shows the need to move the tell tail to the top) and was causing the timer base to stick/excessive friction. Any idea where to find a new one? So far I've only found one website that has it and they're in Australia and charging $32 to ship an $11 part. Or is there a new replacement part number for it (0313666)?
 
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