85-86 70hp Evinrude (stalling out when giving it gas)

[tommyarmour]

I just put a new fuel pump on this motor. And put on a new throttle cable(still slightly too long).

Let me try to explain the problem I am having. I turn the motor off and fish for a little while then I start the motor back up. I push the throttle forward the clutch engages and the engine revs up a little I push foward a little bit more and she starts to die out at this point I usually just pull pack enough to keep it running then try again its still in gear and moving but I cannot give it enough gas to take off. It usually takes me 5-10 full minutes of pushing forward and the engine almost cutting out I immediately back off the throttle to keep it running while still in gear then try again and again and again until it finally catches. When it does it takes right off and blasts on down the river(Columbia River). As long as its warmed up I can let off the throttle until the boat stops and put it in neutral, then I can just push forward and launch a skiier out of the water over and over, but if I turn the motor off and wait 3-5 minutes I will have this same problem. Its very annoying and I assume its a easy fix, my throttle cable is a bit long and the play is too muh but that is just me whining the problem is not in the cable its to do with gas I assume. New gas, Old gas it runs the same. I do have a new fuel pump in it.

Does anyone have any ideas? I would like to fix this problem, really sucks when you want to move to a new fishing spot and it takes 5-10 minutes to get going more than 5 miles per hour.

I will post pictures if anyone needs to see what I am working with.

 

[Will Bark]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

You don't mention using your primer bulb before starting your engine sounds like you are losing prime maybe because of air leak or hot carbs causing gas to leak thru to the manifold and not enough gas left in them to go WOT at once.

 

[Daviet]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

It almost sounds like you might have a needle in a carb that is leaking and floods that cylinder, and it has to clean itself out. Or maybe a float is sinking, have you overhauled your carbs lately?
You could try checking spark when the problem happens, a pain out on the water, if spark is good it is almost surely a fuel problem.

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

Sorry for the late response, I did prime the bulb and it gets really tight. Then after its running and stalling I checked the bulb and its still very tight.

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

I didn't check spark, seems to fire right up, and runs really good and smooth when its running. I always assumed if it was spark there would be problems when running good or bad. I am going to take her out again in the next few days and make a little video of the problem. Rebuilding the cabs would be awesome and in my opinion would almost for sure fix the problem. Dont really want to but if need be I will, got the boat from a state agency they upgraded and left the motor at a local marina very well maintained motor with very few miles on it.

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

It almost sounds like you might have a needle in a carb that is leaking and floods that cylinder, and it has to clean itself out. Or maybe a float is sinking, have you overhauled your carbs lately?
You could try checking spark when the problem happens, a pain out on the water, if spark is good it is almost surely a fuel problem.

Hello Daviet, thanks much for your response, would you happen to have a link to a site that gives a tutorial on rebuilding the carbs in my motor.

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

It almost sounds like you might have a needle in a carb that is leaking and floods that cylinder, and it has to clean itself out. Or maybe a float is sinking, have you overhauled your carbs lately?
You could try checking spark when the problem happens, a pain out on the water, if spark is good it is almost surely a fuel problem.

Do you have a link to rebuilding these carbs?

 

[Daviet]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

Other than a factory manual, I really don't know of any place on line that supplies the rebuild instructions. Do you have a manual, well worth the price, will help with all repairs on your engine.
There are some examples on carb overhauls on youtube (marinedoc) I think. I don't know if the show your specific carb, but might give you a general idea of what needs to be done.

 

[Sixmark]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

It could also be a problem with the S.L.O.W. if so equipped, so double check to see if it has it.

Seeing how you changed out a fuel pump and replaced a throttle cable with one that isn't the right one, I would suggest checking your work, and put the right cable on the motor.

Did it run normal before you did this work?

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

Other than a factory manual, I really don't know of any place on line that supplies the rebuild instructions. Do you have a manual, well worth the price, will help with all repairs on your engine.
There are some examples on carb overhauls on youtube (marinedoc) I think. I don't know if the show your specific carb, but might give you a general idea of what needs to be done.

Hey thanks for all your help, I uploaded a video might not help too much because the problem doesn't seem to be occurring out of the water with muffs on.

http://www.youtube.com/watch?v=a5ubI7lppCM

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

It could also be a problem with the S.L.O.W. if so equipped, so double check to see if it has it.

Seeing how you changed out a fuel pump and replaced a throttle cable with one that isn't the right one, I would suggest checking your work, and put the right cable on the motor.

Did it run normal before you did this work?

The motor had sat at a marina for a few years. I met the mechanic that worked at the marina and he changed the motors out, it wouldnt stay running for him to do a bunch more work, he said to pick up a fuel pump and replace throttle cable. I asked him for the size throttle cable to pick up he measured and gave me a totally wrong size. 2 full feet too long. Non replaceable after you stretch it out a little ways. And the fuel pump indeed kept it running then I tested it and this is what happened. Here is a short video to show you the actual engine and maybe show you if it has the S.L.O.W. or not.

http://www.youtube.com/watch?v=a5ubI7lppCM

Note: Don't want to sound like a big dummy but I had never touched a boat motor or throttle cable up until this incident and I had bad words with the mechanic that didn't finish the job. Our deal was I pay him to change the motors over and get the new one running. Well he was leaving on vacation and pretty much just told me what to do, I was very unhappy with this so I told him he was very unprofessional and didn't finish his side of the bargain. He also explained how he would rebuild the carbs as part of the deal he didn't do that either because there was no fuel pump to tell if the carbs needed rebuilding. He just kept the bulb pumped up to make sure it ran.

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

Other than a factory manual, I really don't know of any place on line that supplies the rebuild instructions. Do you have a manual, well worth the price, will help with all repairs on your engine.
There are some examples on carb overhauls on youtube (marinedoc) I think. I don't know if the show your specific carb, but might give you a general idea of what needs to be done.

I watched this video. http://www.youtube.com/watch?v=o5cxBMDezuU (MarineDoc)

 

[Daviet]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

Try running it with the lower unit in a trash can full of water, on the hose there is no backpressure on the exhaust. It sounded pretty normal to me. Be careful reving it up to high on the hose, with no load on it you could get a runaway, then you will have problems.

 

[tommyarmour]

Re: 85-86 70hp Evinrude (stalling out when giving it gas)

Try running it with the lower unit in a trash can full of water, on the hose there is no backpressure on the exhaust. It sounded pretty normal to me. Be careful reving it up to high on the hose, with no load on it you could get a runaway, then you will have problems.

I have heard a lot about revving it too much with the muffs on, you can see in the video I let off pretty quick and kept checking the hose. I just wanted it to stall out to show you all whats going on. And dag nabbit it just didn't want to happen out of water. I have a can to put under there but I use it for water storage. I might just have to take it out on the water and bring camera and tripod.