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Evinrude 4HP problems

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davejp

New member
"Hi all, firstly, i am a compl

"Hi all, firstly, i am a complete novice when it comes to boating, Having only just decided to get out on the water (or so i hoped)


I have , as mentioned in subject, a 4HP evinrude (s/n: 48B36E B62774) whether this is model number and serial number i dont know and it tends to pick and choose when it will start and run.


on a cold start, i usually, as expected, have to choke it and it will start (sometimes) and run fine for a few minutes and then the revs will fall until it stalls.

once it has stalled, i would have to pull the rope a few times to sort of prime it and then it MAY start and run for a little while again.

when it starts losing revs, i can get away with opening the throttle a bit to keep her running, but not always sucessfully.

I have replaced fuel line and filter and cleaned float chamber as well as spark plugs which have a good spark on them.

I am dreading having to clean the carbs as i wouldnt know where to start basically and i cannot find a manual for this engine due to not having a model number.


Any ideas anyone?

If possible, would anyone be able to tell me what model it is by the serial number?


Thanks in advance!

Dave"
 
"48B36E B62774

The first se

"48B36E B62774

The first set of digits would be the model number, with the remaining digits being the serial number.

However, there is no 48836E or possibly 48B36E that I can find. Could that model number possibly be simply 4836? The "E" is simply a factory run number of no consequence.

If so, model 4836 is a 1978 4hp Evinrude.

I'd suggest (if compression and spark is okay) to replace the water pump, and to remove, clean, and rebuild the carburetor.

If the engine has a built in tank, check the fuel filter that is usually screwed into the bottom of it. More thsn likely though, the engine has a fuel pump and a separate fuel tank.

When running and the problem surfaces, pump the fuel primer bulb, acting as a manual fuel pump. If this cures the problem, suspect the fuel pump.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

Note 2: If the engine should be a three (3) cylinder engine with three (3) carburetors, start the adjustment sequence with the center carburetor.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

When time permits, visit my eBay store at: http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"
 
"Thank you for the reply, i ap

"Thank you for the reply, i appreciate that, Your shop looks promising for parts if ever i need some (saved to faves)

tank is integral with an inline filter (new) - i do have a fuel primer although its not connected at the moment but i will give that a try when i can.

i shall look into doing the carburetor as soon as possible.

thanks again."
 
"Hi again all,

I jumped in

"Hi again all,

I jumped in and did the carb (with the help of a service manual) and have had good results.

The float chamber was smothered in rubbish that i didnt spot first time round, cleaned all that out, cleaned float and assembly, low speed needle (i replaced it and did the screw into seat and 1 3/4 turns out as manual intructed) - it seems to idle smoothly without changing the low speed needle from the 1 3/4 turns out.

The performance of it is good in relation to how it was;

after putting it back together i started her up and she ran quite well for about 5 minnutes, opening throttle and closing a bit, ran steady just above tick over for another 5 mins, then crapped out.

after a minute or so, i got her going again with a bit of tempting from the choke (could this suggest i need a richer mixture?) and she will run for a few minutes then die out again.

also, while i had it running above tick over, but not wot, i decided to rev it a bit and opened the throttle about half way, straight away, dead, no loss of revs, just dead.

on one occasion it died, i did notice the water intakes on the shaft were not submerged, would this have a long lasting effect relating to restarting, IE, would i have ta wait a while to restart after overheating?

any further suggestions/wisdom?

Thanks in advance.

Dave"
 
"Hi Dave,

just out of curi

"Hi Dave,

just out of curiosity, have you managed to get your motor running well yet? I'm fixing up a 1980 4 hp that was been sitting for ages in the garage of the previous owner and have had almost the exact same problems as you on my first test drive in the bucket.

The engine starts ok with the choke pulled out, will rev up fairly well but then starts to lose revs after about 20 to 30 seconds until it dies out. Similar to what you describe, I can get the engine to keep running by futzing around with the choke, which would suggest some kind of mixture problem to my logic.

Before I even started the motor up, did a full carb cleaning and rebuild with a new float and needle valve assembly + new plugs. The fuel line appears to be clean and fuel is fresh. Also replaced the impeller.

Apparently, the seller had tested the engine with gas from his chainsaw (duh!) so even through the plug holes I could see the piston heads covered in black wet gunk.
biggrin.gif
Gave it a quick de-crapping with Powertune into the cylinders, and it gradually started to run a bit better. Still dies off though.

Next on the agenda will be to try to adjust the slow-speed needle properly and to see if that makes a difference. In the meantime, would be interested to know how your project worked out?

br,
Tom"
 
"Hi tom,

yes, the engine n

"Hi tom,

yes, the engine now runs fine although i have not used it on the water yet due to a faulty motor mount.

it turned out for me to be a combination of semi blocked fuel lines and a manky carb.

In the end, what i had done was:

1. Replaced all fuel lines (and filter)
2. Flushed out the tank with water to remove loose dirt (allow to dry for a few hours)
3.The valve on the tank was all crudded up so i kept jabbing a blunt needle into it while having water flow through it to flush out lumps (which there was ALOT)
4. The float chamber was a bit grimey, so i took the whole thing off (carb as well) and gave it all a good clean through piece by piece (i used a diagram to re-assemble it)
5. Turned the mixture all the way lean then 1 3/4 turns out (as manual states)

After all this, she starts second pull with about 1 second of choke from cold and runs until i switch off! I can rev her up, although not all the way due to loss of water.

Hope this helps and good luck!

Dave"
 
"Cool, glad to hear that it&#3

"Cool, glad to hear that it's running well now. I think I'll also look into cleaning the tank and its valve, since if the state of the carb was any indication, they're probably full of sh*te as well.
happy.gif


Thanks for the info!"
 
hi can anyone help with some i

hi can anyone help with some info about a evinrude 5hp outboard the engine started with the normal pull start but then it now has stuck ie try to pull (solid) also when i bought the engine the guy told me it was a 4 stroke but on further inspection i noticed it says 100-1 gas
so it looks like a 2 stroke is that the case
 
"welcome to marineengine.com i

"welcome to marineengine.com ian!

you need to list the model #, year, and as much info as possible to get the best results.....and you need to start a new thread or you could get lost under/in someone elses thread.

if im not mistaken, from what ive read the 100:1 has been revised to 50:1......although it seems like some of the smaller engs had some exceptions.

if im wrong im sure i will be corrected.


how long have you had it?


are you saying the motor is locked up? or just the pull start?

can you turn the flywheel by hand?

sounds like the guy who had it before you who thought it was a 4 stroke may have done some serious damage."
 
"first,as david says.do NOT ru

"first,as david says.do NOT run 100/1---
run 50/1--1 pint to 6 gal gas..
next,ck for a shift interlock,that would keep u fr cranking....
next,pull lower unit to determine,if problem is in pwr hd or lower unit."
 
"i did not re-read,all the lon

"i did not re-read,all the long psts above,..but,...after u start that eng,...u will need to 'feather' the chk...pulll it out,the n push in ..sev times,until it runs smooth."
 
hi lads great help i will run

hi lads great help i will run the engine on 50-1
the engine runs great the flywheel turns free it is just the pull start that is stuck i have checked it seems ok but i can start with flywheel pull
 
"ian, i would remove the pull

"ian, i would remove the pull start and check it out.........there isnt a whole lot that could be wrong in there.

be careful during removal/disassembly those springs on the inside will literally jump out and bite you...........i have a link that takes you to a step by step word for word process for repairing the spring----im just having trouble locating it.

maybe ill run across it soon or someone with the same type link can help you....i dont type very well and i dont want to leave out any steps

DO NOT work on it at the kitchen table----my spring got loose on me a couple of times and once got grease all over the curtains.............im sure you all could imagine the wifes reaction
uhoh.gif


if you have ever done any lawn mower or other type pull start repairs--there shouldnt be any probs.....they are basically the same."
 
hi thank you very much i will

hi thank you very much i will take it to a guy i know who sorts chainsaws & landmowers any idea where i can get a manual for it

regards ian
 
HI CHECKED BUT CANT FIND MY MO

HI CHECKED BUT CANT FIND MY MODEL NO IN LIST
ON THE ENGINE IT SAYS MODEL NO B25B- LCOB
THEN BELOW IT HAS B002828 ANY IDEA WHAT YEAR THIS RELATES TO
 
than you again this is a top s

than you again this is a top site wealth of information
do know anything about a tomos ailsa craig 4hp
 
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