revtothelimit - motorbike forum

XT500 wrote: Wed Aug 06, 2025 3:15 pm

Rockburner wrote: Fri Aug 01, 2025 9:48 am Well .... err - ... this happened :

Those Flymo Pilots are good over rough ground, I have three.

I also leave the top plastic cover off and run them on 40:1.

The carbs do crud up easily but are easy to clean.

40:1? Hmmmm interesting. Cheers for that. I need to sort some fresh E5 and make up more premix.

XT500 wrote: Wed Aug 06, 2025 3:15 pm

Rockburner wrote: Fri Aug 01, 2025 9:48 am Well .... err - ... this happened :

Those Flymo Pilots are good over rough ground, I have three.

I also leave the top plastic cover off and run them on 40:1.

The carbs do crud up easily but are easy to clean.

Refilled with some approx 35:1 and fresh E5 99Ron today and it's running "better" but will still only run at its best on 3/4 - 1/2 choke. Ie when the choke lever is half-way between the "middle" position and the furthest right position. If the choke lever vibrates back to the "middle" position then the engine slows and dies.

I'm thinking that would indicatethe that its running too lean? Not enough fuel to match the air-flow?

I've already stripped the carb and put the small parts through the ultrasonic. I'll give that another try.

Any suggestions?

If you think it's running lean you may have a vacuum leak on the inlet side? The manual recommends 25:1 by the way.

If the carb is a Dellorto I may have a spare in the parts box if you don't get yours sorted.

I also have the L38/L47 manual as a pdf if you would like it.

XT500 wrote: Sat Aug 09, 2025 2:33 pm If you think it's running lean you may have a vacuum leak on the inlet side? The manual recommends 25:1 by the way.

If the carb is a Dellorto I may have a spare in the parts box if you don't get yours sorted.

I also have the L38/L47 manual as a pdf if you would like it.

I'll strip the carb down again when i next have a tinker.

I've found a users manual, is that a workshop manual you have?

It sounds like you have it already. Just had a look and they describe it as an 'operator's manual'.

XT500 wrote: Wed Aug 13, 2025 12:20 pm It sounds like you have it already. Just had a look and they describe it as an 'operator's manual'.

I stripped the carb down again and dropped it in the ultrasonic (in petrol*)

I also made up a new "gasket" to go between the airbox and the carb because the old one, while still in one piece, looked swollen and possibly not creating the best seal (and because I had plenty of gasket paper and was tinkering....) I am going to have a another look at the carb-engine gasket as well and maybe make up a new one of them too.

As far as I can "see" - there isn't anything wrong with the thing - it just doesn't seem to want to run - the carb is a Del'Orto, but the only adjustable thing on it is the "idle".



* had a bit of a calamity - the container I had the carb and petrol in leaked so the petrol emulsified in the de-ionised water in the ultrasonic's sink. D'OH! I gave the carb a thorough clean out again after to (hopefully) make sure there wasn't anything left in any of the passages, using carb-cleaner spray (I hate that stuff, it always gives me a headache).

Got some time in the workshop today, so...

Made up a new carb gasket to go with the new inlet gasket.


Checked the spring valves, they're fine.


I also wanted to check the exhaust wasn't blocked, so that meant the deck had to come off.


Manifold is, not surprisingly, gunky...


But the exhaust can was fine. No blockage at all


The piston however looks scored to fuck.








But at that point i was hot and just wanted to get the fucker running, so i pressed on.



Reassembly with new paper gaskets


So. Back together, and I'd also stripped off the lower vanity casing by simple expedient of getting the solidly stuck cheese-head screws so hot (using a dremel grindstone), that the deck plastic melted and the screws just fell through it!

Cleaned the plug up as well (again) and got it running, roughly.

I was peering at the carb in situ when i suddenly realised i had, somehow (because I'm a complete idiot most likely), completely not seen a screw in the left side of the carb.

It's a fucking mixture screw.

Grabbed a screwdriver and turned it one way, no effect. Turned it the other way and

rrrrrrrrRRRRRRRRRRRRRRRRRR

"Crrk.. Goodwood control we have lift off. Commencing test flight locally at Angels 20 (mm). Crrk Over & out"



Works great! It doesn't "float" unless the ground is properly flat, but it definitely behaves like a hovercraft (it tends to fall down any incline) but it cuts like a good un. That shows approximately 2/3 of the area it needs to manage. I can't push it along because the ground is too rough to support proper hovering, but it's easy to just pull it along.

I had a bit of rope to hand....


For 20 quid and some swearing, I'm happy. I can do the job in about an hour now. Using the strimmer was approximately a 4 hour job, mainly due to pissing about on that bank.

"That'll do pig. That'll do."

And back home for tea and medals

Why no float?

Not fast enough, blade not profiled right or worn down, hole in the skirt, running backwards(!).....????

Count Steer wrote: Sun Aug 17, 2025 8:40 pm Why no float?

Not fast enough, blade not profiled right or worn down, hole in the skirt, running backwards(!).....????

It does float, just not terribly well...

It was also trying to cut grass that is probably longer than it's really designed for, over ground that's lumpier than it's really built for. And it's approximately forty years old!

Byggery and bollox.

Tried to use the pigmo today and it was not happy.

Eventually realised that it was flooding badly, and remembered (dimly) seeing bubbles coming from the float when I ultrasonic'd it. I think it's got a pinhole so I'll need to strip the fecker down again and get the soldering iron out once I'm convinced the float is no longer offering harbour to undesirables!