Reserve Taps

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May 27, 2006
I'm hoping someone will be able to explain the reserve petrol/gas tap operation? On my roadster the normal tap on the left opens when the lever points down. The bit of tube inside the filter gauze means that that side of the tank can't be fully drawn down.
The reserve tap appears to stay closed with the lever down and opens with the lever up. This allows gas to flow between the 2 sides of the tank down to the level of the tube in the other tank, and then you can empty the reserve tap side.
As I see it, because the 2 sides of the tank are pretty much seperate after the top gallon or so has gone. The left side will then empty until the reserve tap is used, the RHS can empty, but even then some fuel will be left in the LHS of tank. :?
Looks like it would work better if the 2 sides were connected above the taps, or if the reserve tap had a high level and a low level take off? Or is there something missing in my set-up?
A standpipe on a Roadster main tap isn't really necessary unlike many other types of tank where the two 'sides' of the tank merge together at the rear.

So you could probably remove the standpipe (I did) if it has the plastic type pipe with the rigid plastic gauze filter cover?
Or drill a hole in the standpipe as low as you can (if it is the older metal standpipe (leaving the standpipe in position to support the metal gauze that you normally find with that type of tap, the 'main' side will then drain completely.

The amount of fuel left on the 'reserve' side is probably less than you might think so don't expect to get too far on the reserve supply.
Run into the same question with my Interstate, using the two types of taps, leaves a good half a gallon in the tank, on the left side, when you have drained all the gas out using the both taps...rather a pain when draining the tank for repairs/cleaning.
Seems senseless to have the main tap at all, but rather more useful to have two reserve taps...which as mentioned above, would allow you to at least use the gasoline you have put in the tank and not be stranded somewhere , with a half gallon still in the tank.
Then on the other side, not bad to know that push come shove, you can lean the bike and let that left over gas, get to the reserve and get again underway, to that petrol station that just closed for the night....:D ....sort of a "reserve" reserve....
Thanks for the info - good to know how it is, perhaps look at a mod when I run out of other things to do to the bike!
Anyone know how to clean oily plugs? - or are they a re-cycling case?
I run a reserve tap on each side. I use the left side as reserve.

I was curious as to how much reserve capacity that gave me so I measured it - I collected six pints. Should be good for 20 or 30 miles, although I haven't actually "road tested" that yet!

F_Magna said:
Anyone know how to clean oily plugs? - or are they a re-cycling case?

Can be cleaned with spray brake cleaner and a mild brass plug brush; opening the electrode and filing the contacts, then reseting the gap...but most will say just to replace the plugs because we are in the habit of not bothering to fix, but rather just to replace parts when they break. Perhaps brand new plugs will also just plain, work better than reconditioned ones.

In this case though....might be rather more important to find out why they are oily in the first place, this isn't the way they should be in a healthy motor. If you just replace them...the new ones will surely be soon oily too, unless you cure the reason for the problem.

On this note...I will give the stage now to those that know better than I, how to check for the reason you have oily plugs... :wink:
Thanks he-who - I've started by fitting new needles & needle jets (2 ring needles, 106 jets). from a short run LHS appears much improved, RHS a bit better, if sooty. need alonger ride & fiddle with the idle air bleed at the weekend. It's a bit like painting the forth road bridge!
good luck ...but remember that oily plugs and sooty plugs...are not one and the same...different reasons for them...oily usually comes from some basic motor problem, and sooty can come from the same, or wrong carb inards, or have to decide which you have, sooty or oily......then one of the kind fellows will be able to help you... :wink:
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