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Johnson 28 SPL 28SPLE28ESLCEA Won't Run

B

Booth333

New member
This is a new thread, former postings under "Johnson 1991 28 SPL Problem"

Regarding: Johnson 28 SPL 28SPLE28ESLCEA
with Electric Start
with Console Throttle / Warm Up Lever / Ignition and Choke
2 Cylinder, 2 Cycle

Use: Currently on 1971 Harris Flote Bote

Concern: Cannot get the engine to run consistently at High Speed and Low Speed at the same time.

Fuel: Non-Ethanol
50:1 2 cycle Oil Mixture

Tank: Clean, No Debris
No Vacuum Lock

Tank to Engine
Fuel Line: Good Condition, Line and Primer Bulb

Coupling to Fuel Pump
Fuel Line: New Fuel Line Added
In-Line Fuel Filter Added

Fuel Pump: New Fuel Pump Installed

Primer
Solenoid: Refurbished with Kit
New Top Plate
New Lever with Schrader Valve
Tested Solenoid, Activates when current applied
Not Tested, Pressure Seal

Carburetor: Refurbished with Kit
New Top Plate Gasket
New Drain Plug Gasket
Main Jet Cleaned, No Obstruction
New Float, Needle, and Seat (Note; Float is installed in correct direction, not upside down)
New Emulsion Tube Gasket
New Welch Plugs

Carburetor Cleaning:
Disassembled, removed Welch Plugs
Flushed with generous amount of Sea Foam
Top and Lower Caps Ultrasonically cleaned
Flushed (again) with Carburetor Choke Cleaner
Note; Upon disassembly, no debris found in Carburetor however Emulsion Tube openings appeared to be slightly gummed up.

Spark Plugs: New QL77JC4
Gapped to 0.030"
Verified to Spark

Lower Housing: Fresh Gear Oil

Water Pump: Okay, good Water Flow

Limitations: No Service Manual

Not Checked: Timing
Cylinder Compression (required value unknown)
Fuel Pump Compression (should be 2 lbs / sq in?)
Ignition Points

Current Condition: Runs at High Speed briefly, then dies.

I cannot seem to get this engine to perform adequately at both Low and High Speed.

Most recently, I had this running well at low to mid-range throttle but then the engine would die when I attempted to run at high speed.
I took the carburetor back off and found that, while top position of Float was level as recommended.
The Float drop was at 0.8", so my assumption was that I had been starving the engine of fuel.
Now, with the Float drop at 1.3", the engine will only run briefly at high speed. Will not start without starting fluid.
It doesn't make any sense.

Carburetor Follower is set to dead center of Cam notches at low speed idle.
No High Speed Idle adjustment on this carb.
Low Speed Idle adjustment set to 1 1/2 turns counter-clockwise from close.

When the engine stops and I remove the Carburetor Plug, there is fuel in the carb, but when I remove the Spark Plugs they are dry.

There is no reason to suspect bad spark, timing, or compression...though those can't be ruled out since I haven't the equipment to test them. In any case, I don't know the what the proper values are.

I have followed all of the logical steps for tuning this engine, but success eludes me.

This has to be the something I'm doing wrong or overlooking with the Carburetor.
It has gone from fuel starvation to flooding to starvation again.

Any help / fresh ideas would be appreciated.
Photos upon request.
 
The main jet clean, no obstruction, but....is it opened to the correct size? It may have a mild film in the orfice that is partially leaning the motor.
 
There are no breaker points on this motor. Have you replaced water pump impeller ?----And hurry, buy or rent a compression tester.----Check flywheel key too.
 
Dear timguy,

Regarding: Main Jet

Concern: Correct Size / Film in Orifice

In order to determine the orifice is the correct size, I need to know what the correct size is.

I ran a wire brush (which came with my refurb kit) through the orifice of the main jet when cleaning the carb.

The carb. has been removed (to adjust my float) a few times and cleaned it each time. Not saying you are wrong, but I think that is a low probability. If you know the proper orifice size, I will check it with some gage pins.

Dear racerone,

Regarding: Water Pump Impeller
Compression Test
Flywheel Key

Concern: Water Pump Impeller Replacement

No, I have not replaced the impeller as I appear to have good water flow through the engine. How would that affect my fuel flow? Overheat the carb.? How hot is too hot?

Concern: Compression

I will purchase a compression tester....they are relatively inexpensive...but again, I need to know what the compression should be. What's an acceptable range between the two cylinders?

Concern: Flywheel Key

I will pull the Flywheel and check to see what condition my woodruff key is in. If stripped, that could explain why I have gone back and forth from lean to rich if the timing is is off. I haven't checked the timing with a gun, as I don't know what it should be for this engine and seemed unlikely that it's gone out of adjustment from the factory.

General Comments:

This engine is mounted on the boat in our river. Getting it out of the water is difficult. I don't have a trailer, so the only way to extract it is via a makeshift ramp that I built with rollers on a wood frame (to get it over the rocks). Once on shore, I have cut used sections of PVC pipe to move it further on shore. The whole system is like moving blocks for the Pyramids. When I rebuilt the pontoon deck, the process took several hours getting it out and moving it uphill. Once I put it back in the water, it has stayed there for about the last six years. The boat actually sits in the ice three months each season. As the water freezes, the pontoons pop up without any adverse affect. The motor gets winterized each fall.

The point is, when working on the engine, I have to be very careful not to drop any parts in the water. It's a bit nerve racking.

If my key is okay, than I can't help but think this some adjustment between the cam and the butterfly in the carb. Also, there is a high speed butterfly adjustment on the port side of the engine that I don't know how to adjust. I assume it should force the butterfly to be fully open when at high speed so that's where I have it. I guess my saying there isn't one was a bit inaccurate.

Thanks for the input guys. I won't be able to work on it for a couple of days, but I will let you know when I do.
 
The water coming out of the tell tale is for the water pump.----That water does NOT circulate through the block.----I suggest you post compression values before doing anymore guessing on what might be the issue with your motor.
 
So drill bit size # would be a 53, eh? Yup, I've done lotsa work on the water. While standing in water too. Flywheel key likely okay unless somebody hit a deadhead or something. You can tdc top cylinder and see if flywheel mark lines up with index mark. Some motors use different marks where tdc should be. So if flywheel stripped off key, or even partially sheared it. A close eye can see. There is a little slop at top of stroke so rock flywheel back and forth, finding the MIDDLE of free play. Then look to see if index mark is right on.
 
flyingscott,

Regarding: Carb Rebuild Kit

Concern: Kit with wire brushes


All others,

Regarding: Johnson 28 SPL 28SPLE28ESLCEA

Concern: Status

I haven't performed any work since my last post as I have just finished pulling out dock and winterizing my other boats and jet skis.

I'm actually fortunate enough to have a cottage on Devil's Lake in the Irish Hills, but also live on the Huron River....so I have two residences, both on the water.

Weather permitting, my next steps will be;

1) Purchase a gage and check the cylinder compression.
2) Remove the flywheel and check the keyway.
3) Remove the carburetor, re-check the high speed jet and low speed adjustment apertures.

There has never been any catastrophic incidents with this engine, but it has a history of running poorly. A few years ago, I took it to Lockemans for a tune up. They are one of the few places that will still work on Johnson engines....the last business still open around Zug Island (the neighborhood is like a demilitarized zone...don't get a flat tire). It ran about the same as before I took it, so maybe I was punked. In any case, they didn't help the performance.

One other thing I need mention.....when installing the new Fuel Pump, I added a few extra inches of new fuel line (to avoid kinking) and a filter. Maybe it's having problems feeding fuel to the carb. and starving the engine?

With the weather turning cold, I may just fix my boat ramp and remove the engine so I can work on it indoors. My patience is running thin, however and I'm considering a new engine (though I really can't afford it). If I sell this one, I will feel guilty about passing the problem onto someone else.

In any case, thanks to everyone for your contributions. I will continue to post as events unfold.

B.
 
They made this style of motor for a long time.----Easy to trouble shoot.----You need spark that jumps a gap of 3/8" or better at the right time.----Correct amount of fuel.----about 120 PSI compression in each cylinder.----Correct compression in each of the 2 crankcases.
 
A sheared key throws the timing off.---And no you can NOT use a timing light to find if key is sheared!----You are pushing the key in and holding it in while cranking it over ?
 
Ha! What ya doing up at 4 am, Racer?
Booth, you need to check the jet, has it ever been removed? Be careful, dont strip it out. Size a screwdriver perfectly to fit.
 
Many folks mistake the nozzle for the high speed jet.----High speed jet is found screwed horizontally into the bottom of the float bowl.
 
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