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HELP 70HP Four Stroke Evinrude

bluefin1

New member
"Been having trouble with this

"Been having trouble with this engine for the last three years and the dealer here cannot seem to find out whats wrong.

Some times engine works perfectly but most of the time it does not. Engine is on a 16 foot RIB so no question of being too small for the boat.

Problem occurs when the boat is not brought up to the plane immediately or when trying to ski some one. Basically it seems to be suffering once there is some load on it.

At full throttle the engine just revs up and down, and I can hardly tow my six year old kid due to lack of power.

Local agent here has been working on it for the last three years but he seems to have given up now. The last thing he replaced was the fuel injector pump. He says no errors come up when he plugs in the computer.

I have taken a short video of the engine whilst it was 'knocking' if this may help. Video was taken at full throttle!!

http://www.youtube.com/watch?v=S7BlAZXXwzs

I really need help on this. Its a practically new engine with very few hours on the clock.

Thanks

Edward"
 
"Hi

Below is the latest rep


"Hi

Below is the latest report I got from the dealer with the most recent work that has been done on the engine and also the model and serial number.

Tried the boat out again yesterday. Once you get it on the plane you can go at top speed no problem (30knots) but as soon as you try to tow some one same problem comes up.

Would really appreciate some help.

Would changing the prop help??

Suggestions till now have been:

Check Nuetral safety switch
Change Harness
Change ECU
Change prop

But I don't know where to start from!!!

Thanks

Edward


E70FTLEE – S16002025



· Removed and serviced Injectors

· Changed Fuel Vapor/Pump

· Changed Spark Plugs

· Run Computer Tests



The only fault shown from the computer tests was “Fuel Injector Failure” This was what led us to believe the fault was from the fuel system.

From the last report we have, the engine has 188 hours but I would think this is now close to 200 or maybe a little more"
 
RIB's and injected 4-stoke

RIB's and injected 4-stokes sometimes creates some funny problems.
What is Your max rpm?
At what rpm does the problem occur when 'loaded'?
Is Your alarm system working as should?
Test in particular the exhaust temp sensor in the exhaust manifold.
 
Max rpm when engine is working

Max rpm when engine is working fine is around 4000.
When problem occurs engine seems to be limited to around 2800 rpm.
How can I check the alarm system and temp sensor? If these were not working properly I assumed this would show up when the laptop is connected to the engine at the service centre.

We have never got the engine to perform the problem whilst the laptop is connected. shold we try to do this?

Some one suggested changing to a smaller prop for more pull but less top speed. Can this be the problem?

Thanks

Ed
 
"The max rpm for that engine i

"The max rpm for that engine is 5800, You are way out.
Try a different prop, around 17"?
What are You running at the moment?
If Your dealer has not reacted on this before, I find it a severe question.
It is most likely the speed limiter kicking in."
 
"So.

Spent a couple of hour


"So.

Spent a couple of hours trying out the boat yesterday again.

On the first go, I gave it full throttle. The boat came out onto the plane no problem. Max RPM we reached was 5000. No way we could go any faster even if we wanted to cos the boat was already too fast and out of control.

I slowed it down left it in gear and gave it full throttle again. No problem again. This I did for a couple of times, even putting it into neutral and reverse before forward again. We lasted about 10 minutes with out any problems.

Then finally it started to limit the revs as usual. Exactly 2800. If we bought sit at the back of the boat with the front high up the engine just runs at max 2800 revs without knocking.

As soon as one of us moves forward and the front starts to come down the engine starts to knock. I assume that this is happening cos once we moved forward it is easier for the boat to plane. Thus less stress on the engine so it tries to increase revs and it has to knock to keep them down to 2800 now.

After trying out for about 5 minutes we could not get to it go.

So we turned the engine off and tried again a few times. Nothing!!!

We then left it stand for about 5 minutes, tried again and it went off no problem. This time i kept it on the plane running at around 4000 revs for about 20 minutes. It never gave any problem. Took it off the plane. tried again and it was stuck again!!

This time we turned it off again and let it stand for about an hour till we had a drink. Tried again and it still would not work!!

There seems to be no pattern to this problem. all we can really assume is that something is limiting the revs sometimes but not always.

When you try to tow some one it seems to limit the revs every time though.

I checked the prop but could not find any markings on it so have no idea what size we have!!

Anyway, this really seems to be some sort of system lock down which the laptop should register.

I will go down to dealer today and tell him that we must run the laptop test when the boat is doing this problem. He said we could not last time because he could not pass the wire through the cover. If needs be i will make a hole in the cover!!!

If the laptop does not pick up then error then I really don't know what to do.

Thanks

Edward"
 
i think your prop is stamped o

i think your prop is stamped on the inside next to the hub mine was there but barely visable.
 
"Does Your alarm system and sy

"Does Your alarm system and system check instrument work?
I still believe there is a temp problem kicking in, and most likely the switch on exhaust manifold.
On the below pick of the gearcase it shows a water screen #38. In some cases that creates some problems and has to be blocked using a part#21.
Do a temporary test by duck-taping that intake so no air may enter.
There should be no problem letting the test cable go from engine even with cowling on. I more thing Your dealer is afraid of getting wet!
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"
 
"PS:
The same intake has to b


"PS:
The same intake has to be blocked the same way if running the engine on muffs, or You will burn out the impeller. It mainly sucks air!!!"
 
"my alarm works only instrumen

"my alarm works only instrument i have is tach and it didnt work till i came to this site. ive run mine on muffs several times(short periods) and didnt know about the #38. reason i know it works it didnt have lower unit bolted on when i bought it. put it together, cleaned carbs, replaced plugs completley rewired(every wire cut-vandalism?). fired it up no water then there went the horn. turned out it was dirtdobber heaven in pick up tube. can you tell me if mine has a #38 is it under the foot below water intake?"
 
"Today's progress ( or

"Today's progress ( or no progress report)

We blocked the water screen as advised but this did not solve the problem.

Dealer had a new ECU in stock and we changed that, but that did not solve the problem neither!!

On the bright side we seem to be narrowing it down!!

Tomorrow dealer will give us the laptop and we will try to see what comes up.

I am still convinced that the engine itself is limiting the system so it must be a faulty sensor some where I hope.

Anymore ideas??

Thanks

Edward"
 
"As far as I remember the only

"As far as I remember the only switches that sets off the SLOW are the temps (2) and oil pressure. For the fault to be stored in the ECM, the failure has to last at least 10 seconds, but any failure that sets off alarm should react immediately.
However I get a bit confused here: Are there one or two persons posting? (David and Edward).
There is another thing that might set off the slow but no 'alarm' and that is high voltage. Normally that even blocks the ECM in permanent SLOW, but that You might see from the lap-top.
I would if nothing shows on the lap-top tried to disconnect the exhaust manifold temp switch and double checked all ground connections in the harness."
 
sorry didnt mean to confuse yo

sorry didnt mean to confuse you. i was just reading and trying to learn something from the prob and troubleshooting tips. i was just curious about the #38 screen. still little green on boats. just didnt want to have to fix water pump. either i dont have one or im blind(#38). sorry for the interruption guys. thank you
 
"OK David.
Just got confused.


"OK David.
Just got confused.
There is a kit available that consists of a solid plate, no screen, and a plug for the tube. On most RIB's I have installed the 4-strokes 50/70, I had to block that water screen off. When flushing engines on muffs I had a 'workshop kit' that I used to install."
 
"mines an old 115tl79r 2 strok

"mines an old 115tl79r 2 stroke. maybe this is on newer models or 4 strokes? just trying not to make any costly mistakes when running on muffs. when i read it i went outside to check but couldnt find mine. thats why i was asking thought maybe i was blind, or looking in the wrong spot. still learnin thanks to all this help everybody gives. thanks for the help!"
 
"David:
Not only complete dif


"David:
Not only complete different engines, but in fact different manufacturers. The 4-strokes are Suzuki."
 
OK.

Will see what we get wi


OK.

Will see what we get with the laptop today.

Whenever we get the fault there is never any alarm going off just the limiting of revs.

Normally the only way to get going again seems to be to turn off the ignition completely and try again until it decides to work properly.


The alarm system seems to be working well though cos it beeps and then the four red lights go off one by one when we turn the ignition on before we start the engine.

Although thinking about it sometimes it also does just after we start the engine!! May this be something?

I am not a technical person so I will have to take the boat to the dealer to remove the manifold and maybe change the sensors.

Is there more than one ground connection? Where are they?

Thanks

Edward
 
"The restart of the system che

"The restart of the system check after start might indicate some bad connections somewhere, might be the key-switch.
To disconnect the switch on exhaust manifold, simple, Follow the leads from the switch, remove the cover for the ECM, and You find the connector inside. No need to remove any manifold. Switch #17, on stb side of engine.
216041.gif
"
 
"Note that if the SLOW has bee

"Note that if the SLOW has been activated, the only way to 'get out' is to restart the engine. Sometimes You may have to wait some 10 sec to be sure the ECM is totally down powered before restart."
 
"Thanks for all your help.

"Thanks for all your help.

Will try all the above out this evening.

I cannot uinderstand how our service agent here has not come up with all these checks!!

So if we disconnect a sensor the engine will still work but will not shut down if there is a problem in teh area where the sensor is situated??

We have been three seasons with this problem now, but looks like with your help we will eventually solve it.

Thanks

Edward"
 
"Unfortunately what fails the

"Unfortunately what fails the most on engines with electronic systems are the sensors and switches.
Problem might sometimes be to find out which one!!
Had once problem with exact same engine as You with more or less similar behavior. Turned out to be a faulty battery switch making voltage peak in the system from time to time, end whenever it happened:SLOW and no codes.
The RIB's need a lot of power when planning and pulling skiers, and the exhaust temp might peak for a mili-second outside the set range. Not long enough to set off alarm, but enough to trigger SLOW. If You still have the original switch and running in salt water, it might be time to change it anyway, they are prone to fail. Unfortunately they have a tendency to disintegrate when removing and must be drilled out. That is not a job for a novice."
 
"OK, I think I finally made go

"OK, I think I finally made good progress today!!

Disconnected the heat sensor switch but this did not help.

Then we hooked up the laptop. As you indicated no problem at all to put the cover on with the wire connected!!! If only the dealer did this when we first asked him to two years ago!!

The program we had did not seem very helpful. From what I worked out you could monitor three items at one time and thats all.

Anyway, we basically went down the list of all the sensors but got no errors even though the engine was still running in SLOW.

At the bottom of the list there was an item Safety Neutral Switch.

When we monitored this we realised that even though we were putting the engine into gear it was still showing on and the engine was always running in SLOW. We tried quite a few times turning off the engine and starting up again and finally one time it went to off. We pushed full throttle and this time the boat took off!!!

So it looks like this is the problem area.

Thats why no errors came up. As far as the engine is concerned this is not really an error. It just thinks that it is still in neutral !!

Where do i find this switch ? Can fix change or at least disengage it temporarily??

Whats the next step??

Thanks

Edward"
 
"Pos 56 on below pick. Located

"Pos 56 on below pick. Located on the shift lever system on stb side of engine.
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"
 
Thanks for the info.

Do I s


Thanks for the info.

Do I simply buy a new one and replace it or can it be checked to see if it is jammed or dirty?

Can I bypass it until the new part arrives?

Here in Malta they do not stock parts and it could take quit some time to arrive!

Thanks

Edward
 
"The only function it has it t

"The only function it has it to prevent the engine from over reving when unloaded. Most likely a dash of WD 40 might solve the problem,. You may remove it, but insulate the cables!!
In Neutral: switch shorted.
In gear: Switch open."
 
Found the switch and the pin i

Found the switch and the pin is seized so not coming out when the engine is put inot gear. WD40 helped but it is still getting stuck so will have to change it.

Tried removing it but then the engine will not start since it is now always 'in gear'

Do you have the actual part number so that i can try to buy it from the local dealer or order it if he does not have in stock.

Onr thing is strange though. If the engine is thinking it is still 'in neutral' when the switch is stuck then i assumed that it would start when in gear. I tried but it did not!!

Thanks

Edward
 
"There are ways to 'fix&#3

"There are ways to 'fix' that. but try to get the present switch working.
If not, the easiest way, temporary is to cut the wires close to the switch, extend them and fit a temporary manual switch while You are waiting for a replacement.
Part number from BRP:5030823
Part number from Suzuki: 37721-99E10"
 
"Finally, engine working perfe

"Finally, engine working perfet after three years!! Kids were on knee board all afternoon yesterday!!!

Faulty Neutral Safety Switch to blame.

Have installed a temporary switch outside the engine until the replacement switch arrives.

Must really thank you for all the help, would never have fixed it without yoru guidance.

Thanks once again.

Edward"
 
"Happy boating.
Sorry for mis


"Happy boating.
Sorry for missing the neutral switch, have to blame it on Alzheimer, has no manuals and going just by memory."
 
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