CB550 Tuning Advice

[Nurse Julie]

Doesn't Nurse Julie has the right tube?

I don't stock fuel pipe Delta. We've always use the Nitrile pipe from Planet Silicone on all our own bikes and restorations. It was fitted to my 500 K1 5 years ago, and the 750 K6 10 years ago and it's still fine.
https://www.ebay.co.uk/itm/130740225601?itmmeta=01M4Z8QJ12VC40M7NPAQCX37YC&hash=item1e70b98641:g:ITQAAOxyOalTX6Br

[Sesman]

Looks like something has changed, Julie.

This is the stuff I bought and it failed in short order!

[florence]

as I keep my bike outside, the biggest problem I have is with UV light.  I have hose with cloth exterior but at the point where it joins anything such as the tap, it cracks up within a few months.

Some will say the obvious answer would be to keep the bike indoors but that is not a possibility, it has to sit in an archway.  Sometimes a tarp is thrown over the bike.

I would rather find a UV and Ethanol resilient hose.

[Neilw]

Looks like something has changed, Julie.

This is the stuff I bought and it failed in short order!

Same for me.

[Neilw]

I've found DIN 73379 Type 3E, which appears to be bulletproof. It has an ID of 5.5mm but an OD of 11.5 mm. It's also reinforced.

Will this fit?

https://www.carbuilder.com/products/ethanol-proof-fuel-hose-6mm-14

I've ordered a meter of this; I'll let you all know about the fit.

[McCabe-Thiele (Ted)]

I would rather find a UV and Ethanol resilient hose.

I used 303 Aerospace Protector Spray to stop uV degradation of a Hot Tub Vinyl Cover when we had one. It worked well. Used it for 10 years, it does not dry it acts as an effective barrier. Not cheap, lasts ages, effective.

You could just spray the hose where it's exposed to light.

[Sesman]

NeilW.

Just for clarity, you tried two suppliers: Honda classics and planet silicon, receiving the same unsuitable product?

[Neilw]

NeilW.

Just for clarity, you tried two suppliers: Honda classics and Planet Silicon, receiving the same unsuitable product?

Yes, the same; they look identical. I'm just not prepared to take the chance; when the new one arrives, I'll cut the existing ones up to see where the issue is. It could also be the little 3.5/7.5 hoses that connect 2 carbs together (I got these from  Planet Silicon too). I definitely need to see which hose(s) are responsible.

I should say that I haven't tried the Honda Classics one; I'm too scared!

[Oddjob]

It won't be the connecting tubes, they move air only unless the bike goes over. They are just there to ensure equal pressures in the float chambers.

This is what I found on EBay. Viton lined.

https://www.ebay.co.uk/itm/260815755996?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20250417133222%26meid%3D31ec5560b8bf43c8aaee0c7a4ec92eb4%26pid%3D102727%26rk%3D1%26rkt%3D1%26mehot%3Dnone%26itm%3D260815755996%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DWatchlistVariantWithPSItemDR_BP&_trksid=p4375194.c102727.m162921

[Neilw]

It won't be the connecting tubes, they move air only unless the bike goes over. They are just there to ensure equal pressures in the float chambers.

This is what I found on EBay. Viton lined.

https://www.ebay.co.uk/itm/260815755996?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20250417133222%26meid%3D31ec5560b8bf43c8aaee0c7a4ec92eb4%26pid%3D102727%26rk%3D1%26rkt%3D1%26mehot%3Dnone%26itm%3D260815755996%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DWatchlistVariantWithPSItemDR_BP&_trksid=p4375194.c102727.m162921

Looks like the same as i have ordered, mine was a bit cheaper - but same stuff.

Good to know about the connecting tubes. Thank you.