Just been re-routing my fuel hoses and whilst doing it I thought I'd check for the flow restrictor in the return line & there isn't one. I shouldn't be surprised on a 1991 bike. I'm assuming they're not something stocked by the dealers anymore so after a bit of advice on the size of the hole required in the restrictor so I can make one.
According to the parts diagram there is supposed to be a flow restrictor in the return line. Looks like it's pushed inside the return line near the Y piece so there is nothing to see from the outside. This would make sense as otherwise the pump would just keep sending the flow back along least resistance to the tank rather than supplying most of it to the carbs.
I think the size isn’t critical so long as it creates a small differential pressure favouring the carbs rather than the tank. I seem to remember the one in mine was a small brass ferrule around 4mm long with a wall thickness around 1/2 mm. Sorry - no chance to measure it currently.
If you use something like I used to replace the standard plastic “Y” piece, you could just compress the return outlet by a mm.
I was wondering whether it was worth replacing the 30 year old plastic Y piece before it broke. Might not be a bad idea to to get a metal Y and crimp one side. Where did you get your Y piece from?
I got it from Aliexpress a couple of years ago - something like £3.50 for 2 at the time. I think they are designed for aquarium plumbing so you might find them locally at a pet supplies place. i would recommend anyone with a carb SS to replace the plastic Y piece as mine was as brittle as glass, and I doubt they will be ethanol proof so now is a good time to change it.
I have a restrictor on the bench in the garage as just doing my fuel lines, I’ll post the measurements tomorrow, just looks like a little brass olive.
Thanks Gents. I'll make up a brass restrictor with 4mm hole and see if I can get myself a new SS Y piece. Good point about the E10 and whether the plastic Y piece will cope with it. Hopefully all the little plastic and rubber bits in the carbs will survive the increase in ethanol. Might have to go to Super although that seems to have 5% ethanol these days.
Esso “Synergy Supreme+” doesn’t yet contain any Ethanol in most areas of the Uk. The only one left I think.
You did well finding that fitting. There are lots of Y type fittings but not many with narrow angles and nothing that looks as suitable as the ones you've purchased.
You may need to make the trip South on a raiding party - I think will you only need to get to the services off jn 41 M1 at Wakefield, but stand to be corrected on that if Esso consider Wakey to be “North England”. Their head office is in Surrey so maybe they do !
Great i'll get some bought. Tried looking for these all last night with no success. Goes to show it's still not easy to find stuff without having the proper search terms.
I think petrol depends on which refinery / storage depot supplies an area as most of the companies use the same place but with their own additives added into the tanker as well as the base unleaded petrol.
The following information on Ethanol content of Petrol may be of interest, particularly for the premium grades and supply location in the UK: https://www.esso.co.uk/en-gb/fuels/petrol https://support.shell.com/hc/en-gb/articles/115005935369-What-is-Ethanol- https://www.bp.com/en_gb/united-kingdom/home/products-and-services/e10-petrol.html#accordion_Is%20my%20petrol%20car%20compatible%20with%20E10? https://texaco.co.uk/pages/e10.aspx The link below is to a website that is monitoring fuel ethanol levels at locations in UK: http://www.ethanil.co.uk/league-table/ Links to Government information are: https://www.gov.uk/guidance/e10-petrol-explained www.gov.uk/check-vehicle-e10-petrol I think there is more information available on this subject elsewhere on this forum. For what its worth, Esso Synergy Supreme+ 99 has been my preference for sometime, including overwintering. It's also worth noting that this information does not apply elsewhere in Europe, so taking a fuel additive on your trip might be worth considering? Hope this helps. Tom.
