Petrol pipe bore for the 250 2C to suit the fuel taps and carb inlets

[julianharty]

Thank you again Arthur and Steve.

Arthur, I'm pretty sure that Dellorto list those bolts in 2 lengths for the different banjos. I've found oddities on some bikes too.

on the page for the banjo union 8796 Eurocarb helpfully list the screw screw 8797 m6x20mm and the washer washer 4052

For 2 of each of these items it's a not insignificant £39.53 including p+p though. I'll try using the single feed items first.

[Arthur Farrow]

Correct but at the end of the day its a bolt

[Steve Brown]

You mean you'd risk the non genuine part? I like a slot head hex bolt me. Oh ok, yes I have used bolts from my gash tray sometimes. A lot.

[BarryCambs]

I'm not sure what the purpose of the balance pipe is? I've happily ridden 130k on my Guzzi with Dellortos without the need for one.

[morini_tom]

Some morinis have one tap which is on/off and one which is reserve (especially the ones with an electric tap)

In this configuration you can ride with only one tap on, so the balance pipe supplies fuel to both carbs, and then when you drop onto reserve you use the other tap.

However any combination of taps and taps are possible and so yes, if you have an on/off/reserve tap on both sides you can just use both taps with a single feed to each carb.

[BarryCambs]

Ah - that makes perfect sense.

Just about to strap the tent on, so if I turn the taps the right way, I'll see you later!

[julianharty]

I discovered petrol weeped around the side (circumference) of the new smaller inlets (as per Arthur's photo) viewtopic.php?p=44416#p44416 as they are about 2mm shallower than the original items (that require the larger bore fuel pipe). The M6 securing bolt on the carb is slightly too long to cope with the reduced depth.

I fitted an extra stainless steel M6 washer below the head of the bolt then added a second (new) fibre washer to ensure the M6 washer didn't stop the first fibre washer from being compressed (there's a small lip and indentation of about 0.8mm and the width of a standard M6 washer is too wide to fit in the lip).

There may be a better longer term fix e.g. to use a slightly shorter M6 bolt (e.g. by grinding off 2mm from the tip of the bolt).

I need to address clattering that emerged from the engine before I spend more time on the carbs

Once the bike is back in working order I'll ride it and see how the revised fuelling settles down. Thank you again Arthur for discovering these smaller bore fuel inlets.

[Parker3865]

Clattering, oh dear! I hope that is not serious.

[julianharty]

Clattering, oh dear! I hope that is not serious.

The kick starter is meeting strong resistance and I've decided not to force it to turn the engine over just in case a valve has met the piston or similar. As I've mentioned in a more detailed post viewtopic.php?f=37&t=7808 I've decided to wait 24 hours before I start to investigate what's wrong... More news in that post as I excavate the engine internals.

[Steve Brown]

CONFESSION TIME! It was me wot said silicon rubber pipe was good for fuel lines. Well to my embarrassment it ain't! Or at least some versions, I suppose there must be silicon and other silicon. My theory was proven to be rollocks today when in front of an audience of hundreds at the VMCC Founders Day, I turned the fuel on for my Camel ready to ride it over to the club stand for a dramatic entrance and make everyone swoon etc. The precious fuel was pouring straight out of the pipe connecting the two carbs. It had split in two and had more cracks evident, it wasn't very old either. I checked the other bike when I got home for any leaks or signs of failure and that is fine and has been there longer too. The pipe had come from a different supplier so maybe the chemical make up varies? I dunno, but the moral is clear-don't listen to me, especially on petrol pipes. Also I accept no responsibility if your P&J suffers a similar embarrassing wetness-BE WARNED!

[George 350]

Steve and all,
Codan R9 fuel hose is resistant to damage/destruction by modern fuels. A good supplier (from my experience anyway) is Hosemaster. See:
https://www.thehosemaster.co.uk/r9-unle ... -fuel-hose for sizes available.
Not cheap, but cheaper than a tankfilul of fuel all over the floor.
Regards, George

[mbmm350s]

The later 1200s like many modern bikes are festooned with fuel pipe adaptors especially at the purge valve.

They use these kind of dirt cheap pipe fuel line adaptors for 6.3mm (1/4) to 7.9mm ( 5/16)
https://www.bikerstoolbox.co.uk/acatalo ... Tools.html

Mark