1971 Johnson 4 hp question

[curtis4769]

Hello everyone, this is my first post here.

I just got a 1971 4 hp Johnson. Model #4w71d.
(got it for only $50, old guy said he hadn't run it in 20 years, looks new under the cowling)
Runs strong but only on full choke.
I already ordered the factory service manual on ebay.

I would like to order a carb kit and impeller for this motor here at iboats.

I just keep going in circles and there are so many part numbers.....so I would really appreciate it if someone could give me a link to both of the parts I need (carb kit, impeller) for this motor.

Thank you for your help.
Curtis

 

[Daviet]

Re: 1971 Johnson 4 hp question

Here are your part numbers.
Carb kit 398532
Impeller 434424

 

[hidef]

Re: 1971 Johnson 4 hp question

Welcome to iboats the little four is a great engine. Order the BRP/OMC carb kit you want the new float if yours uses a cork float you will want to get rid of it. Other things to look at is replacing the old fuel lines with ethanol resistant lines and getting a rebuild kit for the fuel pump. You will want to use 24:1 premix for your fuel mixture the old fours were not fully jeweled until 78. Use the Marine Engine link to cross reference the Sierra part numbers.

http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1971&hp=4&model=4W71D

CARBURATOR REPAIR KIT, ORDER PART #383067

Siera part 18-3090 - IMPELLER, 763735 for plastic housings
BRP part # 0434424 - IMPELLER & KEY for metal housing

 

[curtis4769]

Re: 1971 Johnson 4 hp question

Thanks for the help guys, I have the parts I need ordered.

Also, thanks for the tip on the 24:1, I assumed 50:1 would be fine, is that what the manual recommends? (I ordered the original service manual but it hasn't arrived yet)

Curtis

 

[curtis4769]

Re: 1971 Johnson 4 hp question

I didn't even think about the cork float, would you guys recommend this part:

0396514 - FLOAT AND ARM ASSEMBLY or will the other float be fine?

 

[Daviet]

Re: 1971 Johnson 4 hp question

If that is the new type, use it to replace the old style cork float.

 

[curtis4769]

Re: 1971 Johnson 4 hp question

Thanks guys for your help, it looks like the OMC kit comes with the float, I ordered that one as well.

 

[Daviet]

Re: 1971 Johnson 4 hp question

Keep us updated on your progress.

 

[curtis4769]

Re: 1971 Johnson 4 hp question

Update on the motor:

Installed the carb kit and new float and adjusted the needle valves according to the J. Reeves instructions. Took a little playing but I have it running like a top at idle and high speed.

Replaced the impeller(even though the old one was still in good shape). I thought the replacement impeller was too big, but I rotated the housing clockwise until the impeller fit snuggly inside with the fins on the impeller going the direction it shows in the service manual. I have a nice mist coming out of the 6 holes, so I think the cooling is working properly. Is there any way to tell for sure on this motor? I have heard to touch the cylinder head, but honestly I have never removed one and don't know where that is. Some parts of the motor are HOT and some barely warm. Please advise.

 

[hidef]

Re: 1971 Johnson 4 hp question

If you have a mist spraying out of the exhaust relief ports the water pump is working correctly.

 

[curtis4769]

Re: 1971 Johnson 4 hp question

Thank you guys for all the help, the engine is running like a top. This forum is a wealth of information! The best advice I got here was to get the factory service manual, really takes the guess work out of it! Again, thanks for the tips!