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1982 70hp evinrude cut out problem when in water-from accross the pond.

H

hollygolly

New member
Good day people.
I have recently bought a second hand evinrude 70hp outboard, 1982 about 6 weeks ago. When out of the water on the trailer it starts fine, goes into gear and revs well. but when i put it in the water (sea) and start it it ticks over OK, but as soon as i try to put any throttle on it, it dies, just cuts out. I have tried to get some revs on it, and it will drop into gear and tick over and run at about 3knots, but try any more revs and it cuts out? I stripped the fuel pump and noticed the plastic plug and spring was siezed, so released that and cleaned it all out thinking problem solved, but no still the same. I wnt down today and took the front cover off the carbs and put in some carb cleaner and left it for an hour or so, started it up and noticed it now races ever so slightly, more than it did before. I also noted that when each carb intake was blocked wit a rag it slowed down but did not cut out (engine up to temp) every time, but the middle carb cut out the quickest, i only mention this as someone said this will indicate a problem with the carbs, but as i am not a mechanic i was not sure what to expect. So can any of you guys help, anyone else experienced this problem? I have not yet put it back in the water since flushing out the carbs so have no idea if it is fixed, but just wanted to see if anyone else had similar problems and whjat the fix was?
Cheers
Peter
 
They all run fine on the trailer and will sound good running on 2 cylinders.--That test means nothing.--------Start your trouble shooting with a compression test.-Then check to see if you have strong spark at each cylinder , must jump a gap of 7/16" or more.----Spraying carb cleaner into the throat does very little.----Remove the plug on each carburetor bowl and then remove the high speed jets in there ( use 3/16" diameter screw driver ) and clean those jets.
 
thanks for that, i am away on work duties till Friday but will certainly try all those. I did have someone look at the outboard and tell me it could be the wrong prop, he said if the pitch is wrong it may cause this as it will not pull the boat out of the water? But would it make it cut out as soon as you try any revs?
Thanks.
 
In agreement with Racerone. Your explanation indicates fouled, clogged, gummed carburetors BUT the first step is to check the compression and spark.

Also, you say you're not a mechanic but you took the fuel pump apart... hopefully you got that back together properly. Note that pumping the fuel primer bulb (acting as a manual fuel pump) would force fuel thru the fuel pump if the pump itself wasn't functioning as it should.
 
Thanks again for your help.
I am certainly no mechanic, but am mechanicaly minded and the fuel pump was pretty straight forward. You mentioned the primer bulb, which i used when i ran the engine for a good 15 minutes the other day. If the fuel pump was still at fault, would it have needed re-priming over that short period of time?
Also any thought on teh wrong propsuggestion?
peter
 
The primer bulb does not stay hard when the motor is running !!!---Does not need to either.----------The wrong prop ( too much pitch )means that the motor would not wind up to its rated RPM.--------If the motor stalls it is not the fault of the prop !------------You must understand that lubricating oil for the precision parts / bearings inside the motor is introduced via the 3 carburetors.-------Therefor before you keep running the motor hoping for a " magic fix " you need to take the carburetors apart for cleaning and verify that they are clean.----Also install a new impeller for the water pump.--------Also look at the thermostat and poppit valves to make sure everything is in order there, especially if it has been run in salty water !-------Inspection / maintenance it key to getting the motor running properly.-See post # 2
 
where abouts are you ?
you realy need to get the compression checked anyway but it does sound like you have blocked or
very dirty carbs.

the prop causing this is not going to be the problem at all.

there isnt a prop big enough to stop the engine that will fit on it.
this engine would need something about 40 inch pitch to kill it in gear.

the carbs are nice and easy to take off and strip apart, make sure you have plenty of cleaner ready
to dump the whole thing in once you have as much as you can off the carb.
If you have access to an airline you can blow out all the little pipes and orifices as well.
now to do the job properly you need to get out any plugs that are on the carb body.
These all need to be cleaned out and new plugs put back in them.
they are like little core plugs on the sides or on top of the carbs.
Now also when the carbs are apart test the floats, put them in a cup of petrol with a weight on to
keep them under the petrol for about an hour.
then take off the weight and see if they float and see if any petrol has entered the float body.

take pics as you take the carbs apart, it might help when you put them back together again.

any probs then post a pic and im sure many here will help you..

are you in UK ?

phill........
 
Hi Phill
I am located in the North East of England, and it is very cold and icy here at the moment, just after getting over the 3 days of rain and floods!
I thank you for your input, and will check the compression over the weekend, what should it be as a matter of interest?
I will have the carbs stripped and cleaned as this also seems to be the general sensus. I did clean the plugs a few weeks ago, and though they were a little black and wet, they seemed in good condition, no sludge or build up.
I will be back to you once i have attacked these first problems.
Peter
 
Hi hollygolly
im down south near london and we are getting same weather, so i know you cant go outside unless its a dry day.
The compression im getting is 145psi 147psi and 145psi, but anything over about 120 psi is ok as long as all 3 are
within about 15 psi of each other.
Take off the prop and have a look what size it is,it will be stamped somewhere or on the centre by the nut or gearbox end.
shouldnt think you have got wrong prop.
Carbs realy do need to be very clean,not just the bowl but all the little orifices,float needs to be checked as well
incase they are leaking.
The pipes from the fuel pump go into a 3 way divider, check this is not cracked as ive come across a few that have tiny holes in them causing problems.
Take a few pics of the carbs and we might be able to help show what to clean etc.

good luck


phill
 
Hi Everyone.
Sorry for the delay, been a bit of ice and snow the last week or so, just after the floods? Anyway, i managed to do a comnpression testy on the engine today, it was 130psi (top) 135 (psi) middle & 150psi (bottom) not sure how that compares? I also replaced the plugs, and noticed the plugs that were in had a gap of .70...should it be .30? It started first time in teh cold today mind!! I also noticed that the new plugs were very wet and oily (dark) when i re checked the compression a second time. It does run very sweetly on the trailer, but not had a chance to get it in the water yet..would like to check it again before i start pulling the carbs to bits?
Thanks
Peter
 
racerone said:
The primer bulb does not stay hard when the motor is running !!!---Does not need to either.----------The wrong prop ( too much pitch )means that the motor would not wind up to its rated RPM.--------If the motor stalls it is not the fault of the prop !------------You must understand that lubricating oil for the precision parts / bearings inside the motor is introduced via the 3 carburetors.-------Therefor before you keep running the motor hoping for a " magic fix " you need to take the carburetors apart for cleaning and verify that they are clean.----Also install a new impeller for the water pump.--------Also look at the thermostat and poppit valves to make sure everything is in order there, especially if it has been run in salty water !-------Inspection / maintenance it key to getting the motor running properly.-See post # 2
Click to expand...
Hey racerone I have completely taken my carbs off and cleaned them good, put a new impeller in it and changed the plugs but my 82 70hp Evinrude will idle in the lake but dies when I put it in gear unless I raise the trim up till the prop is barely under water and once I get it to moving and rev up some I can drop the trim down and it will go but if I try to pull it back to idle speed it will shut off do you have any idea of what it could be
 
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