Wristpin

Take the air cleaner off and put your hand over the intake while pulling the rope. That will tell you whether it’s a choke problem.

Is the machine new to you? If so are you aware that the hydro drive will probably have a by-pass or dump valve to allow the machine to be moved without the engine running? If that is open the machine wont move. If it is closed there is the possibility that the pump has entrapped air and needs to be bled. .

I had one of those back in Lambretta days , 1958 ish. Seem to remember that it was a bit hit and miss and rather messy. Haven’t seen it for a long time - may have gone awol when I had the business. Now days I just get a four inch length of the appropriate diameter clear fuel pipe and push it over the engine end of the cable, hold it up heigher than the lever end and fill it with air tool oil ( nice and thin) and work the lever. If in a hurry, blow down the tube to help things along . Back in the days of the original Austin and Morris Mimis the engine earthing wasn’t too good and the choke cables tended to warm up and get sticky when the starter was engaged. . In extreme cases they did a full met down , glowing red hot. Just might be worth checking the Black Horse’s engine earthing. An earth bond from the engine side of any mounts back to where the battery is earthed to the chassis can sometimes work wonders for cranking rpms.

If you think that the yellow wire is the kill, check it out . With the ignition OFF you should have continuity to Earth . With it ON , it should be open circuit. When you say "wont start" do you mean totally dead or "cranks but wont run" ? The danger is that if you’ve got things wrong it’s possible that you may have put voltage through the ignition coil and cooked it, so the first thing to do is to isolate the engine. Disconnect all wires other than the heavy one from the solenoid to the starter motor and crank it over but be prepared to pull the plug lead off to stop it. If it starts it at least shows that you have a runner and can relax and sort out the stopping! I will dig out a wireing diagram but normally the kill wire will go to a terminal on the throttle plate and will have a loop terminal under a nut. The 8 hp lump may have a single charging wire with a “ tubular” connector or a dual circuit alternator with two wires and a double pin connector that can only be fitted one way round. EDIT added https://www.dropbox.com/s/lgchle1pohn1r1z/Lawnflite 504 wireing diag0001.pdf?dl=0 Yes, the yellow is shown as the kill wire. As well as going to the kill terminal on the ignition switch It is also connected to a couple of safety switches which will also prevent the engine from firing unless in the safe position.

Are you sure about that part number? If I’m looking at the correct part the book that I’m looking st says 1662. In stock at my Hayter agent , key 505, for 94p + vat

Possibly has a pulse tube from the crankcase.

Without the key and just putting the pulley on the crank, how much wobble is there? One of the heavier grades of Loctite, such as High Strength Retainer , should sort the problem .

A drop of Loctite won’t hurt but the spring washer should be sufficient. Remember the a liquid thread locking compound effectively lubricates the threads and makes it easier to strip or shear the screw so reduce the tightening torque accordingly.

Why, it wasn’t done up tight enough and time and vibration have taken their toll. The retaining “ bolt” is a1” x 3/8” UNF thread hex head set screw . The spring washer is a 3/8 “ single coil spring washer. Flat washer. 3/8” flat steel washer. Key. Standard woodruff key All from a decent engineers merchant or Horticultural / agricultural engineers.

Don't be in too much of a hurry to bin that lump as those reduction box engines are hard to come by. Strangely enough, a couple of weeks ago, not having seen one for ages, I was brought one to sort out by another "fettler", who had given up on it,

Honda G200 5hp engine . Easy starting Runs well with no smoke Cash and collection from near Ashford Kent £125

It is not the removal of the lead that has caused the problems that we have now but the inclusion of ethanol which is inheritly unstable and also hygroscopic . Fuel stabiliser is useful but the simpler solution is to only buy fuel in a quantity that will be used in a month and keep it in 5 litre plastic cans rather than a 20 litre “Jerry can” . The problem is likely to get worse as while UK fuel containes around 7.5 % ethanol , other parts of the world are on up to 13%.

If they are for a worn engine try a set of Cords. http://www.cordsduaflex.com/whycords.html

Little blue granules?

Not quite so, you can retime the ignition using the Before Top Dead Centre figure from the engine spec in relation to the points starting to open. I believe the setting for a JAP80 is 25degrees or 7/64" BTDC. Points gap 18thou and plug 25thou

I'll leave the tap question to someone who knows. What make of magnetic clutch has it got or did Gutbrod make their own? Some electric clutches are self-adjusting while others require setting with feeler gauges to achieve the correct air gap. If it is driving a cutter deck, check the seized or partially seized blade spindle bearings are not overloading the clutch.

Maybe there’s a reason. Rigger boots are banned on many construction sites and I’ve never seen an explanation for that either. Australian construction sites and mining operations insist on long sleeved shirts to reduce the likelihood of skin cancer.

That’s an interesting observation. I’ve always associated condenser failure to be age related rather than resulting from any other influence.These days I rarely work on anything with an exterior ignition coil , slightly more often on machines with exterior “ platform” magnetos and the bulk of the time on flywheel magnetos. I do change a lot of condensers on the latter group but then they are usually 50+ years old. Not sure. This lot have been changed in the past 15 months or so.

Exercise caution if you split the box, they are usually held together with steel taptite self-threading screws. Steel into alloy, plus moisture and the passage of time equals seized screws and a possibility of sheared screws; at which point the law od Dr Sodt takes over.

I now realise why the Hayter connection came to mind. Spicers were used in Murrays and Hayter were the distributors both for red Murrays and similar machines in Hayter green. We used to see Foote boxes in Ariens YT models but I believe that Foote had a disasterous fire at their factory and never got back into production, but the designs were bought by Husqvarna.

Don't want to start a controversy but the Peerless box referred to will not put up with that sort of treatment for long. All Peerless literature makes the point that the machine must be stationary for gear selection. In my 30 years of running a garden machinery business, most as a Peerless agent, we rebuilt dozens of their MSTs (Manual Shift Transmissions), nearly always as the result of such abuse. If the owner was lucky it was just new selector keys but often also the replacement of the most frequently used gear wheels where the engagement dogs had become rounded as well as the keys. Yes, they were filled with Bentonite grease but this tended to be thrown outward to the inner walls of the casing and dry out there, away from where it was needed. We always used to add a cupful of semi-fluid grease to help fill the voids. Spicer boxes were quite a rarity in the UK and were a product of Dana Spicer the big US transmission manufacturer - more often associated with trucks and off-highway equipment. We very rarely saw a Spicer transaxle but something at the back of my mind says that Hayter was the source of parts etc for their horticultural boxes. http://www.dana.com/aftermarket/brands/brands/spicer-drivetrain

I don'tthink that you can shift on the move with that box. That said there was at least one ride-on manufacturer who used a manual box with an in-line shift pattern but moving the lever sideways disengaged the drive to the box allowing a sort of shift on the move. Before the advent of lower-priced hydrostatic boxes, Ariens and Snapper used a stepless variable speed transmission consisting of a friction wheel running at right angles to a drive disc. When the friction wheel was running further from the centre it was in high ratio and closer into the centre, low. When it crossed the centre the drive was reversed. Sounds a bit Heath Robinson but actually worked well on walk-behinds and lighter ride-ons. MTD, used and may still use, a similar system on self-propelled vacuums and snow blowers.

Rain - what's that? 36 thou!!! - far too much. Slide the bushed components onto the axle one at a time and grasp them at 9 and 3 o'clock, if there's any "wiggle room" it's too much.

It is a parallel shaft with a straight key. Get two pieces of "tin" and cut a U shaped slot in both and slide them in between the sump and the pulley from opposite sides to protect the sump. In these circumstances the seal is expendable! Find a friendly mechanic with oxy-acetylene and get the pulley and its sleeve cherry red, leave it to cool and then give it the diesel soak treatment. It will then probably lever off with a couple of tyre levers or pry bars. Protect the sump further with some scrap steel under the heels or fulcrums of the bars. Or use folding / fox wedges as suggested by Headexam. Perhaps someone knows why they are called Fox wedges?

That axle looks to be badly worn and even a new bush won't restore the distance between the two sprockets. I cannot overemphasise that to "get a good clutch" everything has to be right - don't kid yourself that near enough is good enough. At some point in the production of 21s and Ospreys Hayter used to fit a heavy duty O ring around the chain and sprockets to contain the sag in the chain and scraping the inside of the chain case . Part number 4946. Essentials for a good clutch. No end float on the axle so that no clutch movement is absorbed by the axle shifting sideways. No radial wear on the axle either where it passes through its bearings in the cross tube or where the sprocket or hub rotate on it. No bush wear in the sprocket allowing it to "flop" left and right and not run at 90 degrees to the axle. No bush wear in the hub - same as for the sprocket. Eliminate wear in the handlebar clutch lever lockout so that the full amount of cable pull is maintained when hand grip is released. There's a fairly simple fix for this. Get it right and you will have a machine that spins its wheels and drags you along, ignore it at your peril.