New Project(s)

[Rockburner]

More shenanigans....

Took the wheels for the Puch for new (heavy duty) inner tubes and fitting last week.







The original Cheng Shin tyres are tired, but still usable with plenty of tread.

The tyre guy (Rubber Ranch) even managed to get one of them on without tools.... just a LOT of lubrication!

This week I blagged myself a new (2nd hand) twistgrip for the Puch, and went to fit it. I stripped down both the new and the old twistgrips, mainly to try and figure out why the old one was so stiff. It had a fair bit of surface rust, but nothing untoward in it. What it DID have though was a small steel "spring" acting against the barrel . I also stripped off the old grip (still usable) for use on the new unit.

Initially I put the new unit (without the grip), but as I was gently screwing up one of the two screws that hold it in place (I've also drilled an indent in the bar to hold the assembly in place without too much pressure), the sodding plastic cracked completely across the top! GAH!



SODDIT.

Then it occurred to me that it might be repairable..... so I dug out my soldering iron and had a go: first at the original (which had cracks, but none were completely across the part), then the new part. The original is so sun-faded it's virtually white... it should be black!










I wasn't going for "pretty", but they both ended up "functional", which right now is good enough!

Given that they both seemed solid, I decided to use the "new" casing, with the old barrel (it's a bit longer, oddly), with the "new" cover piece (the steel bit over the cable fitting), and reassembled it and fitted it. Note I left out the the "damper spring" because I couldn't see why on earth it would even be in there!






Looks much better! and the throttle movement is now free and easy, and returns easily - much better!

I aslo "derestricted" the bike: by the simple expedient of removing the air-filter with the metal plate across it from the airbox. (will take a photo of this next time).

Bike now runs better, and is easy to control

[Rockburner]

So - having improved the Puch, I returned to the JAPton.

I had an idea that the issue with the carb tickler might have been the paper gasket between the jet block and the main body (the surfaces this gasket mates to are not the smoothest....). So I stripped the carb down and put a small amount of blue-hylomar on each face of the gasket and reassembled it.

No difference. Whatever is preventing the tickler working correctly is still evading me. Next attempt will mean going into the float bowl itself and seeing there's something odd about the interface between the tickler and the float. I've been doing some reading up and it seems that the new nylon floats sometimes cause minor problems so it's worth taking a look.

[Count Steer]

Nice to know that Rubber Ranch is still going. (I'm still using one of his keyrings from about 12010!). He used to come and change the bike tyres in the office car park but moved to Kent so I switched to the Guildford Tyre bike place in Chilworth...interesting getting the LT (or GT, can't remember) in and out of their workshop.

[Rockburner]

Oh yeah - Also - last week I "fixed" the hole in the JAPtons crank cases (timing chest actually).

I did stick an endoscope down it, but there wasn't a lot to see!

I cut down the new bolt so that it was roughly the length required to fill the cases, with a crush washer on top:



Then fitted it in with a good amount of Soudall Fix-All smeared into the threads and around the crushwasher and head. With any luck that will act as a seal and thread-lock even though the bolt isn't done up that tight. I tried very hard NOT to strip the threads so only did it up as tight as I dared....



Obviously will be keeping an eye on it, but I can't move it with my fingers... so it's an improvement !

[Rockburner]

Nice to know that Rubber Ranch is still going. (I'm still using one of his keyrings from about 12010!). He used to come and change the bike tyres in the office car park but moved to Kent so I switched to the Guildford Tyre bike place in Chilworth...interesting getting the LT (or GT, can't remember) in and out of their workshop.

He's based out of Bagshot now, very convenient for me: my office is in Bracknell,

[Skub]

Screwd could probably print you a twistgrip for the Pooch.

[Rockburner]

Screwd could probably print you a twistgrip for the Pooch.

Now I have a spare to take measurements from, it's a possibility.

[Screwdriver]

Indeed I could. Meanwhile, soldering rarely if ever works without reenforcing material (like copper strands etc). Ideally you would hot staple it first and only use a soldering iron at 250ºC or less depending on the plastic. Most soldering irons are way to hot, burn the plastic (even though it looks good) and the "repair" is cosmetic at best.

PS I often see people recommend using zip ties as filler but they can be nylon or abs (or anything really). The only good weld is when you use the same filler as the parent material.

[Rockburner]

Indeed I could. Meanwhile, soldering rarely if ever works without reenforcing material (like copper strands etc). Ideally you would hot staple it first and only use a soldering iron at 250ºC or less depending on the plastic. Most soldering irons are way to hot, burn the plastic (even though it looks good) and the "repair" is cosmetic at best.

PS I often see people recommend using zip ties as filler but they can be nylon or abs (or anything really). The only good weld is when you use the same filler as the parent material.

All true, i probably wouldn't trust it on a road bike, bit for a little field bike it's holding up at present.

[Rockburner]

Took the JAPton out for a spin round the block this evening.

It might run ok at less than 1/4 throttle, but any more than that and it starts bogging down, won't fire at all, then after 2 or 3 deafening explosions from the exhaust it'll pick up and run well for about 10 seconds before it starts bogging down again.

Rinse and repeat again and again if I try to ride it anything more than 1/4 throttle (ish).

And obviously it's still pissing oil....




So... Back to to the tuning leaflets....

[KungFooBob]

For £500 + expenses...

[Rockburner]

For £500 + expenses...

You'll tune it up properly and make it oil tight? Luvverly, when can you pick it up?

[cheb]

What thread is the dubious bolt, I might have a suitable tap.

[Rockburner]

What thread is the dubious bolt, I might have a suitable tap.

Not sure, bit would need to go one size up from the current, and obviously strip the engine to nigh on its component parts before doing a tap job.

[Rockburner]

It might run ok at less than 1/4 throttle, but any more than that and it starts bogging down, won't fire at all, then after 2 or 3 deafening explosions from the exhaust it'll pick up and run well for about 10 seconds before it starts bogging down again.

Rinse and repeat again and again if I try to ride it anything more than 1/4 throttle (ish).

So... Back to to the tuning leaflets....

I still can't get my head around whether these symptoms are the carb set too rich, too weak, or something else completely.

The Amal booklet seems to suggest that issues with fitting in the exhaust are ignition related.... But that doesn't balance with the fact that the engine WILL run properly for a few seconds before it bogs again.

[Skub]

It sounds like it's getting some fuel,but not enough,though the backfire thing would make me think it's more an ignition fault.

[Rockburner]

It sounds like it's getting some fuel,but not enough,though the backfire thing would make me think it's more an ignition fault.

In this context, what does "ignition fault" even mean?

As I say, it'll run ok for a bit, then it seems as if something "builds up" and it stops firing, until the fuel in the exhaust detonates, and it clears up and runs again.... Until the "blockage" builds up again.

[Screwdriver]

Check the woodruff key hasn’t sheared off the flywheel.

[Rockburner]

Well, I've still not figured out what's wrong with the JAPton. Did some checks last week and fuel flow is good ( more than half a litre per minute, which ought to be fine).

Raised the needle by one because i thought it might be a bit weak, and tried starting it up and although it started easily enough, its still spitting back and backfiring.

I'm beginning to think the ignition timing has slipped, so i took a cover over the magneto drive sprocket to check it.
Seemed fine so went to put the little cover back on, and bugger me if the sodding thread didn't strip.

GAH!

So I'm going to put the JAPton aside for a bit and concentrate on the other projects i need to get done before winter, and will very likely spend the winter stripping the thing down and learning more of its foibles.

[Rockburner]

Well, that's the end of that.

Puch is gone.

Some utter cunts broke in last night (we think) and lifted the Puch.

Have spent the afternoon trying to make the workshop more secure and have moved the JAPton somewhere secure, (hopefully), and bought more security for the Rockster, but it's a wooden shed, there's only so much that can be done in an afternoon.

Will probably get more security soon, but I'm seriously hoping they were just chancers on their way home or similar. Next door also had their cars emptied, but they were silly enough to leave them open, apparently.