1993 4HP Johnson

[floatfan]

Morning all!

I bought a little fishing boat yesterday with a 1993 4HP Johnson Model # J4RDHETB on it. I bought it from a lady whose husband passed away, so the boat & motor have been sitting for the past couple of years. According to her, it was running when he last used it. Other than replacing the fuel with new before testing and changing out the gear oil...is there anything in particular I should check on before attempting to fire it up? Also, any idea what fuel/oil ratio I need? I had an old 9.8 Merc previously that was 50:1, but I found some discussion online that this may be 100:1. Figured I'd check with the pros here.

Thanks in advance! I'll post updates on what I find once I get off work and get a chance to clean it up and dig in.

 

[tphoyt]

Go with 50:1
Do a water pump service when you do the lower oil change.
If it sat with fuel in it you will likely need to clean the carb. But it’s possible it was stored correctly to just look over the fuel delivery system and check for leaks. If it all looks good see if she will run.

 

[floatfan]

Go with 50:1
Do a water pump service when you do the lower oil change.
If it sat with fuel in it you will likely need to clean the carb. But it’s possible it was stored correctly to just look over the fuel delivery system and check for leaks. If it all looks good see if she will run.

Thanks. 50:1 it is. I'm crossing my fingers that the previous owner ran the fuel out before storing it. The fuel tank and hose were stored separately in his storage building, so I'm hopeful. Yeah, impeller update was on my list as well.

 

[floatfan]

I only had time to spit shine the outside on my lunch break, but it cleans up pretty good. Fingers crossed it runs as good as it looks.

 

[saltchuckmatt]

I only had time to spit shine the outside on my lunch break, but it cleans up pretty good. Fingers crossed it runs as good as it looks.

Yes, she cleaned up well. Interesting that they didn't upgrade the 4 hp deluxe on that 93 model like they did the 6 and 8 hp.

 

[floatfan]

Yes, she cleaned up well. Interesting that they didn't upgrade the 4 hp deluxe on that 93 model like they did the 6 and 8 hp.

It does say deluxe on the back of the motor. Is that what you mean?

 

[saltchuckmatt]

It does say deluxe on the back of the motor. Is that what you mean?

In 91 or 92 on the 6 and 8 hp and others, they moved the shifter to the front and put the low speed idle mixture screw inside as well as other things. When I first saw the motor I said to myself....."that has to be an 80's motor"

 

[floatfan]

Well, I got home yesterday, changed the spark plugs (old ones still looked fine, but I'd already bought replacements), sprayed some fogging oil in before putting new plugs in, replaced the fuel hose & bulb from the tank to the motor, filled with new 50:1 mix and went to see if it'd start. The pull cord was nearly impossible to pull, but some PB Blaster fixed that. Pulled and pulled and pulled and no luck. It had spark, so I took the carb off. Getting fuel from the fuel pump line into the carb. Carb bowl was full of fresh fuel, and carb looked clean to me. I'm about at the end of my limited mechanical knowledge. Thoughts or suggestions on what I could try to get it to start?

 

[tphoyt]

Put some fuel oil mix in a spray bottle or an old water bottle with a hole in the cap and squirt it into the carb. If she runs you will likely need to clean the carb. Keep us posted.

 

[floatfan]

Put some fuel oil mix in a spray bottle or an old water bottle with a hole in the cap and squirt it into the carb. If she runs you will likely need to clean the carb. Keep us posted.

Thanks, I'll definitely try that. I went ahead and ordered a carb kit online this morning, so that's scheduled for this weekend.

 

[oldboat1]

"ran when last used"!! Disassemble and soak the carb in lacquer thinner (or solvent of your choice), then clean all passages with thin wire. Finish by spraying with carb spray. Idle passages under dome on top very important. Test with idle needle set at 1 1/2 turns c.clockwise from lightly closed.

 

[floatfan]

"ran when last used"!! Disassemble and soak the carb in lacquer thinner (or solvent of your choice), then clean all passages with thin wire. Finish by spraying with carb spray. Idle passages under dome on top very important. Test with idle needle set at 1 1/2 turns c.clockwise from lightly closed.

Yeah, she really didn't know. Her husband passed away and she had no idea what she had.

The low speed needle is the only adjustment, right?

 

[oldboat1]

Well, not exactly. Motors have a throttle control, and many a carb mix adjustment (older ones). You have a throttle stop on the tiller handle, it the stop is working. Start by setting your link and sync according to the manual.

 

[saltchuckmatt]

Yeah, she really didn't know. Her husband passed away and she had no idea what she had.

The low speed needle is the only adjustment, right?

Low only.

 

[floatfan]

Well, not exactly. Motors have a throttle control, and many a carb mix adjustment (older ones). You have a throttle stop on the tiller handle, it the stop is working. Start by setting your link and sync according to the manual.

Yes sir, I adjusted the throttle stop using the knob on the end of the tiller, per the service manual.

 

[floatfan]

I took the carb apart and did a thorough cleaning on all the jets and passages. Put her back together and on the engine and still nothing. Called myself checking the spark yesterday, but I guess not. No spark. I bypassed the cutoff switch by unplugging this doohickey, and she fired right up. Now I have to track down a wiring issue.

I have a water pump kit in route, but not here yet. Service manual shows a discharge up high, which I assume is the 4 holes, then more water discharging below the cavitation plate. The water from the 4 holes was more of a trickling, not even really a spray. I've never had an outboard this small... maybe it's normal??

 

[saltchuckmatt]

Yes sir, I adjusted the throttle stop using the knob on the end of the tiller, per the service manual.

There is an adjustment at the screw labeled #2 on the carb breakdown. Roller adjustment. Probably leave it alone until you see if it's running correctly.

 

[saltchuckmatt]

I took the carb apart and did a thorough cleaning on all the jets and passages. Put her back together and on the engine and still nothing. Called myself checking the spark yesterday, but I guess not. No spark. I bypassed the cutoff switch by unplugging this doohickey, and she fired right up. Now I have to track down a wiring issue.

I have a water pump kit in route, but not here yet. Service manual shows a discharge up high, which I assume is the 4 holes, then more water discharging below the cavitation plate. The water from the 4 holes was more of a trickling, not even really a spray. I've never had an outboard this small... maybe it's normal??

You will need a new kill switch part number 75 on this part list. Not always fun to replace by the way.

Can't believe they didn't put a tell tail on a 93 but maybe. I'm working on an older 4 hp and really there is now way to tell. Check head temp or pull and make a visual on the impeller.

 

[floatfan]

Here's the video of it running and the water output

 

[floatfan]

You will need a new kill switch part number 75 on this part list. Not always fun to replace by the way.

Can't believe they didn't put a tell tail on a 93 but maybe. I'm working on an older 4 hp and really there is now way to tell. Check head temp or pull and make a visual on the impeller.

So you think it's the switch, rather than a loose connection?

See my video I just posted. I don't see a telltale, but not 100% what I'm looking for since the water flow schematic shows it from the side only.