How To Repair Primer Bulb On Gold Series Lawn Boy

Here's an erstwhile-timer with everything; electric start, cocky-propulsion with three-speed transmission, aluminum deck -- a 1997 high-cease machine at present long out of production.

Model number is 10546. Series number is 7904361. I managed to get a parts catalogue and some specifications off of Backyard-Male child'southward website. I even found an operator'south manual here.

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It has a few little issues:

Leaky float-bowl needle valve in the carburetor?
Hard starting.
The battery is non OEM. It needs to have a mounting clench fabricated for information technology.

So, for starters, I'll want to get at the carburetor and remove it for some TLC. I have no guidance hither from a service manual, so I'll just go along as it appears that I should. There may be missteps in what follows.

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Recoil Starter Removal

Release the starter cord from its keeper/guide by prying open the slot in the keeper/guide a scrap with a suitable screwdriver blade

Four x-24 ten 3/8" hex head screws w/captive apartment washers, 5/16" A/F.

Shroud/Fuel Tank Removal

Have the fuel tank's shut-off valve closed.

V No. x x 3/4" hex washerhead threading screws, five/16" A/F. 4 of the screws are in obviously sight. One of the 5 is tucked away underneath at the rear, straight below the fuel filler cap. At that place's a short tubing elbow that connects the fuel tank's outlet nipple to the carburetor. There are no clamps on it -- it'southward just a force fit onto its nipples. That may be function of the fuel leakage problem on this mower. The tubing came off its nipples very hands.

It looks like I could have removed the shroud with the recoil starter nonetheless on it.

Anyway, that all gets 1 to here, where things are pretty much accessible.

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Carburetor Removal -- MONDAY, Feb 25, 2022

An obvious clip secures the air cleaner cover. Release the clip, and the air cleaner cover and foam filter element tin come up away, revealing two pigsty plugs at either side of the carburetor'south throat.

(Now is a good time to check primer bulb action. Pressing the primer bulb should consequence in a healthy dollop of fuel being forced upwardly out of the carburetor'south master jet.)

Remove the two plugs (they pull out easily) and you have screwdriver access for the two 1/4"-20 x 3/four" screws that fasten the carburetor to the engine'south crankcase (No. 3 Phillips recess). And here's the carb off the crankcase.

Note the following:

There'southward a flat heat shield between the carb and the engine, with a gasket on either side of it. Note the heat shield's orientation and set it aside.
If the inboard heat shield gasket is in good status but stuck to the crankcase, just leave it be.
Squeeze the throttle cable's retaining ears to free the cablevision from its bracket, and unhook the cease of the cable from the slider.
The governor spring on this engine is a torsion spring. Governor spring tension works to open the throttle; air vane motion works to close the throttle.

And hither nosotros are with the carburetor removed and up on the bench.

Float Bowl And Needle Valve/Seat

4 No. viii 10 5/8" filister head threading screws spike the float bowl to the torso of the carburetor (No. 2 Phillips recess). Hither's the whole thing taken apart.

Note the following:

The float looks awful, but I tried information technology in solvent, and information technology does float.
There's no float level aligning.
The needle valve has a resilient tip. This one looks fine.

I'm going to launder the carburetor and reassemble information technology without replacing anything. Nosotros'll run across how this works out.

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The Needle Valve Leaks, Alright -- Wednesday, Feb 27, 2022

There's slight fuel leakage out the throat of the carburetor, so I'll supercede the needle valve and seat. I'll as well supervene upon that dreadful looking float, only in example it'southward subpar and contributing to the leakage problem.

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Carburetor Parts Obtained -- WEDNESDAY, MARCH vi, 2022

Hither they are.

There we accept:

Bowl gasket.
Needle valve, seat and clip.
Intake gasket.
9/64" I.D. primer tubing.
1/4" I.D. fuel line tubing.

The float is no longer available. The guy at the small-scale engines shop where I get parts assured me that the floats never fail.

All went together well, except for the fuel line tubing. I'll accept to re-use the original, pre-formed tube. The tubing length is too curt for regular tubing -- it kinks when trying to make the corner that it needs to between the fuel tank and the carburetor.

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High Weirdness In The Electric System

Something is seriously wrong with this automobile'due south electricals. I'll return to this when I have it truly figured out.

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Wiring Problem Solved -- Midweek, February 27, 2022

Here'due south a simplified schematic of the mower's wiring.

Somewhere, sometime in the by, someone had misconnected two wires. The alternator'due south output wire had been continued to the 'kill' terminal of the bail-operated run/impale switch, and the kill wire had been continued to the alternator's output concluding.

So, the kill function was inoperative; the engine was beingness stopped by the restriction alone. When the run/kill bail was released, the kill switch was shorting B+ to B-, quickly draining the battery.

If nothing else, this illustrates the fact that i never knows what one may come across on old equipment. It's a prophylactic bet that it'south been tinkered with at in one case or another, to God knows what manner of outcome.

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The Spark Plug

Lawn-Boy's specs call for a Champion RJ12C. The plug that'southward in the engine is an NGK BM6A, similar so.

Hmmm. Information technology'southward in expert condition, and information technology does fire. The gap is manner below spec. Backyard-Male child calls for a 0.035" gap. The NGK'southward gap is 0.018". Permit's endeavour setting the gap to 0.035", and see how that works.

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Aye! A nice big good for you spark. All the same, I'll supplant the NGK plug with a Champion RJ12C. Ane deviates from OEM spec at one'southward peril.

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New Spark Plug Obtained -- THURSDAY, FEBRUARY 28, 2022

Hither's the Champion RJ12C alongside the NGK BM6A.

Two unlike plugs, just with the same thread and reach. The NGK is a not-resistive plug with a three/4" hex; The Champion is a resistor blazon with a thirteen/16" hex.

Anyhow, I gapped the new spark plug to 0.035" and tested it --it works. Information technology'southward in the engine at present, awaiting further testing of the mower.

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Blade Removal -- TUESDAY, FEBRUARY 26, 2022

Here's a view of the blade.

The hex nut is a prevailing torque type, 5/8"-18, fifteen/16" A/F. That iv-pronged affair is a mulching fan. An impact wrench gets the nut off easily. Removing the nut, mulching fan and bract gets you to here.

That rectangular slice is the blade commuter. It's stuck fast on a taper. Give a corner of it a rap with a plastic-headed hammer, and it will break free of its taper.

Muffler And Exhaust Ports

With the bract driver off, you're confronted with this.

Three v/16"-18 10 3/4" hex washerhead screws (1/2" A/F) holding the muffler in place. It seems that the muffler is supposed to be removed for periodic cleaning of the frazzle ports. I'm skeptical nearly that, simply let'due south have a wait.

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Here's the muffler removed.

And here'due south a peek up into the exhaust ports.

Hmmm. Those ports look pretty clean to me. Until I see evidence to the opposite, I'1000 calling hogwash on exhaust port cleaning.

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Rear Wheels -- WEDNESDAY, FEBRUARY 27, 2022

It's a safe bet that the rear wheel drives could stand up cleaning and fresh lubricant, so let's get on with removing the left side bicycle for starters, and dismantling the drive.

Under the cycle's hubcap is the 1/two" A/F hex head of the wheel's stub axle. Unscrewing that gets one to here.

Yes indeed, plenty of dirt and dried out grease. The hex nut is a 3/viii"-sixteen prevailing torque type, 9/xvi" A/F. The hex nut resides in a hexagonal cavity at the back of the bicycle's peak adjustment arm, so there'due south no demand to have a wrench on it while unscrewing the stub axle. (For what it's worth, the wheel's ring gear has 43 teeth.)

I'm glad I printed out a copy of the illustrated parts breakdown for this machine, because there's quite a lot to the wheel drives. Here's a view of the bulldoze pinion gear with the drive cover taken away.

That pinion gear's installation represents 10 components arrayed on the cease of the axle. Removing them all frees the wheel pinnacle adjuster, which frees the axle from the deck. Here's the analogy from Lawn-Boy'due south parts catalogue.

And here's a view of all the bike drive components laid out on the bench.

The components are laid out from inboardmost (upper left) to outboardmost (lower correct). Following is a list of all the items in club from inboardmost to outboardmost.

Externally keyed thrust washer.
Keyed thrust washer.
Retaining clip.
Resilient friction band.
Rocking key actuator due west/rocking central.
Pinion gear (fifteen teeth).
Keyed thrust washer.
Pinch spring.
Retaining clip.

Note that the rocking key is a different part from left side drive to right side drive. All the other parts are the same for left and correct sides.

Now I have a lot of washing to practise, then it'southward on with the right side wheel drive. When I have both bicycle drives and bike height adjusters removed, I'll be able to remove the rear axle/transmission and tend to it.

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Rear Axle/Manual Removal -- THURSDAY, Feb 28, 2022

With the wheel meridian adjusters removed, the axle ends are free of the deck. At present it's time to unhook the self-propulsion engagement cablevision, complimentary the V-belt from its pulley on top of the transmission and disconnect the shifter cable.

There's a plastic cover over height of the manual.

The embrace is fastened to the deck past two ten-24 x 1/ii" hex washerhead screws (5/sixteen" A/F). Remove those two screws, and then keep as follows:

Unhook the self-propuslion engagement cable from its bail. Depending on the cable's tension adjustment, this may or may not exist readily doable. If the cable can't be unhooked from its bail, unfasten the cable's bracket from the deck.
Unhook the self-propulsion engagement cable from its lever down below.
Take abroad the manual embrace.

That gets yous to here.

Note the 2 iii/8" A/F hex washerheads. Those are the heads of ii 1/4"-twenty x ane 1/4" screws that fasten the engagement lever to the transmission. There are 2 ane/ii" long spacers associated with the screws underneath the lever. Remove the screws, lever and spacers. The V-belt can exist freed from its pulley.

Remove the ane/8" x iii/4" cotter pivot from the shift lever'south shaft, and pry off the shift lever. Force the shifter cable end out of place and disconnect it from its bracket. The rear axle/transmission unit of measurement is free to come up out. Here it is up on the bench.

At the long right side axle, remove and clean the sleeve, a steel washer and a felt washer.

Gearbox Bottom Cover Removal

Half-dozen hex washerhead one/4"-20 ten 3/4" thread rolling screws (3/8" A/F). Here's a view of the opened gearbox.

That looks fine, really. The grease is well distributed and not dry. What I consider to be hard shifting may just be the nature of the beast -- not something that can be 'corrected'.

And so at this point, 1 must inquire oneself, "Should I permit discretion exist the better office of valour and but button the thing support?"

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Hmmm.

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Oh, what the hey; why not? Let'due south go ahead and tear the thing downwardly, clean it and reassemble information technology with fresh grease. We might larn something.

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Gearbox Disassembly -- Friday, MARCH 1, 2022

Hither's the illustration from Lawn-Male child's parts catalogue.

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Ok. I've dismantled the intermediate shaft and the axle and cleaned all the components, which brings me to here.

There'southward the beam with its right side bearing still on it. The gear sleeve is still at that place besides, pinned to the axle. There'south no compelling reason to unpin it, so I'll just leave that be.

The bearing should come off to have its bore properly cleaned, but the axle is rusty and the bearing won't slide off.. I'll brush the axle on my wire bicycle automobile and get the begetting off for cleaning.

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Done. And that leaves me with a filthy gear case with its input pulley, bearing and gear withal in place.

I can't permit the bearing to be immersed in solvent, but to dismantle the input shaft components and printing out the bearing might be folly. So, I'll clean up the gear example as best I tin can without wetting the bearing with solvent. And so I can reassemble the unit with fresh grease.

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Hmmm.

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Oh, what the hey. I've come this far; I may every bit well go the whole nine yards.

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And here are the gear case'south input components.

From left to right we accept:

Brawl bearing. As near as I can make out its tiny markings, it's an SKF 6203-2RS; 17mm bore x 40mm O.D. x 12mm width, sealed both sides.
Input bevel gear/spindle (12 molar gear).
Spacer and ii caster halves.
Flat washer.
three/8"-24 nyloc hex nut (ix/sixteen" A/F).

Now I'll do a dry, rehearsal reassembly followed by final reassembly with fresh grease. And with that, the machine ought to be ready for another twenty-two years of service.

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A Kinked Cable

I don't similar the looks of this.

Pictured in a higher place is the lower end termination of the self-propulsion control cable'due south sleeve. The cable's jacket has fractured, and the cablevision is meeting its terminator at a astringent bending -- that's stressful for the wound-steel sleeve of the cable.

I came up with a slap-up fix for that using a 1/4"-xx coupling nut and a couple of small hose clamps.

I bored through a coupling nut 7/32" (cablevision jacket bore), then half way through xix/64" (approximate terminator diameter). So I sawed the coupling nut in 2 lengthwise. That got me these two pieces.

I clamped those onto the terminator/cable-jacket junction like then.

And at present I have a prissy, straight, stress-relieved cablevision sleeve termination. The cable moves freely in its sleeve, as it ought to. That may last indefinitely.

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Battery Clamp -- SUNDAY, MARCH 3, 2022

The original battery and battery housing were missing from the mower; a 5Ah rectangular sealed lead-acrid battery has been substituted. The substitute battery affords no really skilful mode to clench it in place. The best I could come up with was this.

That's a length of 3/4" All-Round galvanized strapping, attached with two 10-24 screws in the original bombardment housing mounting spiral locations. Information technology remains to be seen how well that scheme holds upward.

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Uh-Oh -- SATURDAY, MARCH 16, 2022

I had the engine running for a few minutes today when I took the motorcar outside, to free upward some space in my workshop. The battery exhibited a tendency to 'walk' off to i side nether its restraining strap.

I did a quick-and-dirty fabrication job to come up up with a side-to-side restraint for the battery.

Peradventure that will finally do the task right.

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All Done -- WEDNESDAY, MARCH 6, 2022

I took the room temperature machine outside where it's minus three degrees Celsius (26.6 degrees Fahrenheit). With the recommended three primes it started on the first pull, ran for a few seconds so died. 1 more prime and one more pull got it running again, and it kept running. The battery appears to exist taking a charge from the alternator. 'Nothing more to exercise now but wait for the weather to plow, and see how the mower performs.

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One Last Touch -- Sat, MARCH 9, 2022

The recoil starter's pull handle is shabby.

The handle's shank has split up. A 1/2" copper pipe coupling is a snug slip fit over the shank, and closes upward the split up nicely.

And Another 'Final' Touch on -- Thursday, MARCH 14, 2022

The mower's owner has inspected the machine, and he constitute fault with the tension of the self-propulsion bail. It seemed to him that the bail's tension is noticeably greater than it was before I added the strain relief to the cable's termination. I tin can't see how my strain relief improver could have affected cable tension, but I can only have the possessor's perception every bit 18-carat, and go along to adjust the cocky-propulsion cablevision's tension.

Self-propulsion cable tension adjustment has two simultaneous effects -- on 5-belt drive tension and on bail tension at the handlebar. Greater 5-belt drive tension results in greater bond tension, and vice versa. What'south wanted is a relatively light, comfortable bail tension while even so providing adequate 5-belt drive tension. Here's the adjustment procedure from the Backyard-Boy Operator's Manual.

I wanted to be able to observe V-belt tension every bit I fabricated the adjustment, then I went about it a little differently. Post-obit is my procedure:

1) Unhook the self-propulsion cable from the bail lever.

ii) Unhook the self-propulsion cable from the transmission's V-chugalug tensioning lever.

iii) Remove the transmission cover (2 10-24 hex washerhead screws, 5/16" A/F), and reattach both ends of the cable. That gets you back to where you started from, but with the transmission encompass out of the style of your judging V-belt tension. At present you lot tin loosen off the 2 jam nuts (1/2" A/F) on the cable jacket's termination, and arrange and effort constructive cablevision length (tension) every bit required.

In my experience, 5-belt drives don't need to be tightly tensioned in order to operate satisfactorily. The belts exhibit a 'wedging' activity as they wrap around their pulleys. It'southward that wedging action that gives the belts traction, and the wedging action is operative even with relatively light belt tension.

Once y'all've struck a satisfactory balance between Five-chugalug tension and bail tension, you can unhook both ends of the cablevision again, and button everything back upwards, skilful to get.

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