Questions on 1987 Johnson 4hp

[bobmwsc]

Motor is a 1987 Johnson BJ4RCUD 4hp

I was hoping that all I needed to do to get ready for getting on the water was swap out the plugs and call it a day. I was wrong. The plug swap was fine and I was glad they had the plugs at Walmart for just a few dollars a piece. I snapped them out, put some new fuel in the tank and it wouldn't start. I figured, and was correct, the carb was all gummed up. I took the motor apart, which is a huge pain, and got the carb out. I was looking online for what to clean it with and found that you can soak the entire assembly in Pinesol without having to worry about rubber or plastics degrading from the carb cleaner. The carb came out very clean and everything was clear. The attached photo is the only one I remembered to take after I cleaned it with the Pinesol.

Reinstalled and still no good. I had spark so I figured maybe a fuel line was clogged. Found that one of the lines had pretty much collapsed so I got some replacement fuel line. Still wouldn't start and now I figured I clogged the carb back up with gunk from the fuel line [emoji849]. Disassembled again and brought it to work and tossed it in the ultrasonic cleaner. Brought it home and reinstalled. Still nothing. I fired a shot of starter fluid in and I was getting it to sputter and finally got it to fire up.

Here are the questions...

Warm start it fires up no problem but I can't get it to fire on a cold start without a spray of starter fluid. Any ideas? Maybe fuel / oil ratio? Cover states 100:1 but I've read that it was changed and I need to use 50:1 so that's what I've been doing.

Any recommendations on a new starter handle? With the repetitive pulling when it wouldn't start I was ripping my fingers apart. Is a full grip snowblower handle okay?

Along those same lines I figure I should replace the starter rope though I'm not sure what size to replace it with.

This motor doesn't "pee" like other outboards (probably due in part that the fuel tank is mounted on the shaft out over the water). Instead the water is supposed to weep out with the exhaust. How much water am I supposed to see coming out though? I do see it dribble out but I'm not sure if it's enough. Time for a new impeller? Are they tough to swap out?

I'm hoping to get it out on the water when soon to make sure the motor stays running under load but with the rain in the forecast that may not be until mid May.

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[Weldorthemagnificent]

Put an impeller in. They just kind of sputter out the exhaust. But with a new impeller, for probably 12 bucks, you know what you have. As for the starting, is the spark good and hot? Bright blue not orange. If that's good, go back to the carb. The idle jet on these is a tiny little hole and it doesn't take much to block or slow it down. Think infinitesimal. Also condition of the seals and gaskets in the carb. Like the little donut one that seats around the needle. Carb kit is probably $20. Then on to the fuel pump. If everything else was gungy, that probably was too.

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[ppine]

I had a motor like that on a sailboat once. It was a one pull motor. Sounds like the fuel system alright. Have you done all the obvious like a new fuel filter? Rebuilding the carb might be the answer. When I returned to the marina with that motor I always disconnected the fuel line and ran the motor dry which made a big difference. Very soon you are going to find the problem and really like this motor. Check the fittings on your fuel tank. They can wear out and cause the fuel line to suck air.

 

[CedarRiverScooter]

You need to take carb apart & run wire thru the passages. Soaking in pinesol isn't enough. Get a kit & change out needle & seat. Mine was hard to start too
& carb rebuid fixed it.

You can get starter rope at Farm & Fleet by the foot. Don't use plain nylon cord, it won't last.

 

[bobmwsc]

You need to take carb apart & run wire thru the passages. Soaking in pinesol isn't enough. Get a kit & change out needle & seat. Mine was hard to start too & carb rebuid fixed it.

All the passages were clear the first text when I soaked it. It got clogged up again with the innards from the old fuel line. The second time I tossed it in the ultrasonic cleaner at work. Again all the passages were clear.

I will pick up a carb rebuild kit though. It's sitting in my Amazon shopping cart now!

Any idea what size starter rope these outboards take? I've seen that it comes in 3, 3.5, and 4mm and that using the wrong size can cause it to become tangles when rewinding.

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[Pappy]

I own three of these engines...among the 90 or so engines I own.
Your carb passages are still not clear if the engine will not idle properly and start easily.
Carb must be completely disassembled. This includes the removal of the plug at the top of the carburetor and replaced with a new one which comes in an OEM kit. Did I mention you need to replace parts to do a proper rebuild? Aftermarket kits will probably not have this part nor will they have a float at the very least.
Adjustment needle, nut, and packings have to come out, high speed nozzle gasket has to be removed and replaced (if so equipped) so it does not suck air, the idle tube needs to be cleaned and verified with a piece of small wire then a spray of carb cleaner or brake clean. Needle and seat have to be removed. High speed jet has to be removed.
Secondly, on a cold start the choke blade must be COMPLETELY closed, not almost closed or close enough. the only air getting through must come from the calibrated air passage in the blade.
These engines are super little engines and start easily and run well.
Pine Sol may or may not do an adequate job..........
The 100:1 sticker should have been removed by a dealer. In fact I am thinking that you have a 1985 engine instead of a 1987. If you supply the model number I will verify for you.

 

[bobmwsc]

Thanks for the info. I was looking at an OEM Johnson carb rebuild kit. I know it comes with a few extra parts for other models but I believe it's the appropriate one.

Evinrude/Johnson Kit Ay, Carb Repair 439073 https://www.amazon.com/dp/B0035L5COU/ref=cm_sw_r_cp_apa_i_nIqXCbP1QXXY8

Attached is the label from the motor. Model is BJ4RCUD.

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[Pappy]

The CUD indicates a 1987, just as you said. Proper oil ratio for that engine is 50:1.