please help

knoxvil

Recruit
Joined
Jun 18, 2009
Messages
5
i have a johnson 4.0 outboard engine dont know the year of it but here is the model number (bj4brcde). the problem with it is after about 15-20 mins running half or full power it semi ceases up and wen it cools down it will start up again i have no manual to check out a breakdown of the engine and i cant find a manual, please can anyone help.
 

bankerjohn

Chief Petty Officer
Joined
Mar 21, 2008
Messages
444
Re: please help

BJ4BRCDE

B = Belgium
J = Johnson
4 = 4hp
BR = Euro rope start
CD = 1986
E = model run

I don't see that particular model on any of the parts sites, but I suspect that the diagrams for the J4BRHCDE model should be very close, if not identical, to your motor.

Sounds like you need to rebuild the water pump!
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: please help

I hope it isn't overheating as you could be causing severe damage to it. There should be a good spray of water coming out the holes at the back of the leg part way down from the cowling. You should also be able to hold your hand on the top of the head (the plate the plugs screw into) for at least a slow count to three. It could be gas related too but you said semi seizes which would be heat related.

Manuals can be found on ebay and other sources. Look at the top of this forum in the Top Secret File for manual vendor choices. I would strongly suggest you get one soon. Best of luck, Rick.
 

knoxvil

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Joined
Jun 18, 2009
Messages
5
Re: please help

ih rick wondering if you can help me again i have replaced the water pump as it had discintegrated. but it is still overheating and i cant find were the water is suppose to exit from thir is only 6 holes which is the out let for the exhurst please can you help
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: please help

ih rick wondering if you can help me again i have replaced the water pump as it had discintegrated. but it is still overheating and i cant find were the water is suppose to exit from thir is only 6 holes which is the out let for the exhurst please can you help

Water is supposed to blow out those 6 holes in droplets, along with exhaust. This is only part of it, most goes out with the underwate exhaust.

I hate to tell you this, but pieces of rubber from that disintegrated pump have probably lodged in the cooling system passages and plugged it up. The only way to get them out is go on a search mission. That means start disassembling the motor till you find them all. Sorry about that.

Moral of this story to others reading this: That is what happens when you don't replace that impeller as a regular preventative maintenance item. This one went 13 years, which is remarkable. However, maybe it has been replaced before.
 

knoxvil

Recruit
Joined
Jun 18, 2009
Messages
5
Re: please help

i have replaced the water pump and cleared engine and pipes of any blockeges an its still over heating can some one help me please its driveing me up the wall
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: please help

knoxvil: As F_R said there is probably some rubber from the impeller blocking the water flow somewhere. First, have you got the leg well into your barrel. The water pump needs to be totally submerged in order to pump. Make certain your well above the pump. If it still fails to pump you can pull the leg and connect a hose directly to the water tube and try flushing it that way. It would be a good idea to pull the head cover as well so that if you do get pieces moving they have a place to exit as the passages in the head are so small they may just lodge there. Have a look here for a parts breakdown of your motor. I would normally say to pull the thermostat while flushing but I don't believe your motor has one. I know mine doesn't but mine is a 71. To check for overheat you should be able to hold your hand on the top of the head for three seconds. I hate to bring it up but each time it overheats you are running the risk of causing damage. Let us know how it goes.

http://shop.evinrude.com/
 

knoxvil

Recruit
Joined
Jun 18, 2009
Messages
5
Re: please help

thankyou for all your help it was the rubber seal at the top of the water pump it was slightly bigger than the old one :D
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: please help

Fantastic. Another 4 HP is back on the water. Congrats..Rick.
 
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