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I've been checking some stuff on my 900 bevel twin, and took off the float bowls only to find that the rubber o rings that seal the choke jets have become pieces of jelly. After literally hours going through the o ring sizes in the catalogue I have made an educated guess on the size that I need, and I hope that it is right at nearly £8 a pair. I did an internet search to see what rubber is resistant to ethanol and few are, with the best being EPDM, so that is what I have ordered.

What worries me though is that Viton is not listed as ethanol resistant, and AFAIK, all carb float needles are Viton tipped, so there will be trouble down at mill........ I don't know if Dell'Orto are making replacement needles tipped with EPDM, but if not, then there will be a lot of engines that will be flooding.

Colin

Use Esso supreme Colin, although it states E5 on pump according to Esso website it is Ethanol free

The problem is George that when I am out and go onto reserve I have to get fuel wherever I can, and twice now I have had to get a gallon of E10 in order to get me to a filling station that has some E5, and both times the next station only had one E5 pump, and there was a queue for it. We with old bikes are in a right old pickle! Cars are luckier, they can carry a spare gallon of E5.

Aye Colin,

So far and 200 miles beneath the wheels after two fills with E10 and Castrol Valvemaster at the recommended rate of 1ml to 1litre of fuel, I have not had any problem from the AMAL MKII 'Viton' needle. Time will tell as E5 etc are in short supply up here and in many places unobtainium or at the end of long queues.

Hope you get it sorted.

Good health, Bill

Hi Colin

I'm now kinda resigned to replacing the needle valves on a regular basis. I have 3 in store right now, my Dramah having pissed petrol all over the place at the start of the season ... Before that it was my Vento and before that my Laverda Corsa.

Not much fun, at 13€ + each.

Emptying the float bowls may delay things .. dunno.

Bummer.

Craig

Edit: Ignore this (sorry, the strike through code isn't enabled on this Forum so I've put it in red)
]P.s. If they work, let me know the size of the choke O ring will you? While I can understand their commercial reasoning, the thought of buying a full seal kit from Dell'Orto doesn't fill me with joy.

Colin: the O ring still seems to be available as a separate bit from Dell'Orto UK - ?

Hi Craig,

I didn't want to buy the original o rings because mine have turned to jelly, so are probably not compatible with ethanol. I will let you know if the new ones fit OK, and the size.

I received a reply to an email that I sent to Eurocarb asking about ethanol, which states that THEY are waiting for a response from Dell'Orto as regards replacement rubber parts........ It was so much easier years ago when we had never heard of ethanol.

Colin

Ah! Got ya ...

The o rings fit. So here we go: if anyone is looking to replace their Dell'Orto choke jet o ring and they want to ethanol proof it, EPDM is touted as the most resistant material. The code is BS007 and the size is 3.68 bore, 1.78 section and o/d 7.24, just state that the material must be EPDM.

I looked up a few sites where various rubbers were compared for resistance to ethanol, and Viton was rated poorly, but Eurocarb sent me a link to a site which thought that Viton was resistant to ethanol....... Suck it and see I suppose.

When I drained my 900's rear carb, a ball of what looked like varnish was floating in there. We live in strange days.

Colin

I'm confused if you look up viton rubber / ethanol on the interwab in general the answer is viton has excellent resistance to ethanol?????
Cheers,
George

Dellorto makes a needle valve for methanol . it is not rubber tipped so no problems with the viton tip

Eldert



[quote="Ventodue"]Hi Colin

I'm now kinda resigned to replacing the needle valves on a regular basis. I have 3 in store right now, my Dramah having pissed petrol all over the place at the start of the season ... Before that it was my Vento and before that my Laverda Corsa.

Not much fun, at 13€ + each.

Emptying the float bowls may delay things .. dunno.

Bummer.

Craig

]