JAPton blog

Discussions and updates on your new bike, your new build, your wishes, wants and desires
User avatar
Rockburner
Posts: 6054
Joined: Sun Mar 15, 2020 11:06 am
Location: Hiding in your blind spot
Has thanked: 11010 times
Been thanked: 4039 times

Re: JAPton blog

Post by Rockburner »

mangocrazy wrote: Fri Jul 24, 2026 9:42 am Well done, that man. Perseverance pays! The exhaust sound with no silencer was enough to wake the dead. What's it like with the silencer?
Cheers!

TBH, err... not a lot different! :D :D

IIRC the story goes that it's off an old BSA M21 (or something similar) and was only chosen by my Dad because it's the correct bore to fit the enormous downpipe! :D
crust wrote: Fri Jul 24, 2026 9:56 am Fantastic!!!

What an excellent reward for all your hard work and perseverance :thumbup:
Thanks!
JackyJoll wrote: Fri Jul 24, 2026 12:52 pm I have never found those nylon bases prone to leak, so it should be fixable, maybe with a replacement gauze.

Any piece of Hylomar that comes off downstream of the gauze will roam around the float bowl like the Flying Dutchman, until it causes trouble.

I mounted a small resin-filled coil too close to an iron cylinder head and the coil cracked.
I do still have the old coil, and I know where to source them if I need a new one. I think it's far enough away, but given that I want to do another slight mod... it may well get moved.

Re the nylon filter - I've been scouring the photos I can find online and none of them seem to have that lip - so I think I've just got two very old, work filters and will buy a couple of new ones at the earliest opportunity (Sunday at Ardingly if I make it, Sunday evening online if not. :) )


Thanks everyone for the replies, tbh there were times I wasn't sure we'd get this far. :D I can't wait to get it on the road... :D (It's currently still registered and insured, and doesn't even need an MOT iirc!)
non quod, sed quomodo
User avatar
Rockburner
Posts: 6054
Joined: Sun Mar 15, 2020 11:06 am
Location: Hiding in your blind spot
Has thanked: 11010 times
Been thanked: 4039 times

Re: JAPton blog

Post by Rockburner »

Actually, one thing I should admit to... if only for recording the idiocy for future referral....

When I did the ignition timing I didn't check the documentation for the Mag.

The mag shaft actually has a direction indicator on it (in the document it's an arrow scratched onto the end of the shaft, on mine I think it's a punch mark that's distinctly off-centre). The arrow indicates the desired orientation of the shaft when setting the time... it must be pointing "down" when you're setting the timing so that the spark occurs at the right point in the 4-stroke cycle (the mag is driven by the camshaft, which turns at half engine speed)



....




I completely forgot about that mark, and so didn't check it when I did the ignition timing. :roll: :? :? :?

I had a 50% chance of getting it right.... :D :D :lol: :lol:
non quod, sed quomodo
User avatar
Count Steer
Posts: 15937
Joined: Mon Jul 19, 2021 4:59 pm
Has thanked: 8064 times
Been thanked: 5713 times

Re: JAPton blog

Post by Count Steer »

Rockburner wrote: Fri Jul 24, 2026 2:11 pm Actually, one thing I should admit to... if only for recording the idiocy for future referral....

When I did the ignition timing I didn't check the documentation for the Mag.

The mag shaft actually has a direction indicator on it (in the document it's an arrow scratched onto the end of the shaft, on mine I think it's a punch mark that's distinctly off-centre). The arrow indicates the desired orientation of the shaft when setting the time... it must be pointing "down" when you're setting the timing so that the spark occurs at the right point in the 4-stroke cycle (the mag is driven by the camshaft, which turns at half engine speed)



....




I completely forgot about that mark, and so didn't check it when I did the ignition timing. :roll: :? :? :?

I had a 50% chance of getting it right.... :D :D :lol: :lol:
Probably find the engine was running perfectly....backwards. :D
The plural of 'anecdote' is not 'data'.
User avatar
Noggin
Posts: 10155
Joined: Thu Mar 19, 2020 1:46 pm
Location: Ski Resort
Has thanked: 19662 times
Been thanked: 4969 times

Re: JAPton blog

Post by Noggin »

Mate, I'm sitting here (in the last throes of a migraine) and grinning like a raving loony !!!! How bloody awesome!

I'll be honest that I mostly. just look at the pictures cos I don't really understand most of the words!!!

But seeing that start and the noise . . . . WOWOWOWOWOW Bloody freaking awesome :) :)

:bblonde: :bblonde: :bblonde: :bblonde: :bblonde: :bblonde: :bblonde: :bblonde: :bblonde:
Life is for living. Buy the shoes. Eat the cake. Ride the bikes. Just, ride the bikes!! :bblonde:
JackyJoll
Posts: 4448
Joined: Sun May 03, 2020 10:11 pm
Has thanked: 245 times
Been thanked: 1230 times
Contact:

Re: JAPton blog

Post by JackyJoll »

Image

Yeah that doesn’t look right.

There’s no doubt Amal are capable of selling bad parts.
User avatar
Rockburner
Posts: 6054
Joined: Sun Mar 15, 2020 11:06 am
Location: Hiding in your blind spot
Has thanked: 11010 times
Been thanked: 4039 times

Re: JAPton blog

Post by Rockburner »

So, I couldn't help myself and wandered back over to the workshop this afternoon. :D

My first intent was to sort out that banjo union.

I started by taking it apart and discovered that I'd done it up so tight that the washer under the bolt had disintegrated!
Image

But weirdly, I still don't believe that was leaking!

I started examining all the bits as closely as possible and started to get suspicious about the banjo union itself:
Image

I then dug through all the old odds and sods that I had from Dad's workshop...

And eventually I discovered that I had a nearly new Amal nylon filter!
Image

I think this was part of the upgrade parts I bought for the Monobloc - that's where I found it anyway, in the amongst the Monobloc stuff. It definitely does NOT have that lip.

So, I fitted it, and re-did the petrol pipe on the banjo union as well and ... er... it seems to have fixed it! :D :D

I also found I have a couple of competely useless twin feed banjo unions...
Image

So while I was waiting for fuel to seep through the filter, I had a mooch around the rest of the bike...

And found this:
Image

Buggeration!

So, I started stripping the rear mudguard off the bike:
First off - the catch-tank holder.
Image

Image

That long screw is what holds both the mudguard on, and the catch tank!
Image

Removing the upper bolts
Image

All undone, and it pulls out actually surprisingly easily.
Image

You can see the "cut out" on the side clearly here, and this is the cause of th cracks.
Image

The larger crack is clear :
Image

Sorry - did I jump ahead of myself... yes there's 2 cracks
Lower end
Image

Upper end
Image

Cleaned off the inside and marked the end of the cracks with a white paint pen.
Image

The holes were drilled easily after judicious use of a centre punch
Image

3mm each should be enough. (They look a bit bigger because I cleaned then up a bit with a larger bit.)
Image

The mudguard went back in fairly easily too.
First getting that long set-screw in place
Image

I was sweating having to take the rear wheel out, but I didn't need to: the set-screws at the bottom end are allen-heads, and there's enough clearance to get the long set-screw out of the bracket, luckily.

Once I had the mudguard back into place.. I had a close look at the fitment.... and now I'm wondering why the hell the cut out is there!
Image

I then fitted the tank strap.

First I got the tank out of the way - there's just enough play in the fuel hose to allow this :
Image


More ultra-lightweight fitments...
Image

And I locked-wired the R-clip just to be safe.
Image

The other end of the strap is yet more in the ultra-lightweight theme
Image

Fitted the seat
Image

Fully bolted down
Image


A while ago I decided that I don't like the Unity Equipe screen that comes with the nose-piece, so I made up a lower, darker version.
Image

It needs a bit more work, the top corners need to be curved off and tidied, but that shouldn't take long with a dremel.
Image


I fired it up again in order to try to get the tick over improved (it either hunts and dies, or revs like crazy at the moment)
Didn't realise that strap was actually pushing against the downpipe... oops! :D
Image

Gassed myself, obvs!
Image

The last piece... Dad's home made primary chain cover.
Image

There's nothing left to fit.
Image

I pondered taking it out at that point..... but realised I'd run out of daylight! :lol: :lol: :lol:

I am interested to see how it runs ... I expect there'll be a fair bit of carb tuning to be done.

Hopefully soon! :D
non quod, sed quomodo
Lutin
Posts: 728
Joined: Mon Mar 16, 2020 4:52 pm
Location: Just across the border in the Republic
Has thanked: 374 times
Been thanked: 388 times

Re: JAPton blog

Post by Lutin »

Splendid. :clap:
Blundering about trying not to make too much of a hash of things.
Post Reply