Pri-On-Res... Silly Question!

:lol:
I've got a really silly question, but I'm just not sure about it!

I'm only used to bikes with a On(rear) Off (Down) Res (forward) fuel tap.

Can anyone please confirm when I'd need Pri?
After running dry of fuel?

I'm guessing On (down) for normal running Res (forward) obviously when low on juice,but unsure on Pri!

 

Pri when you want to let fuel out.

I use it when I go to start the bike and it's been sitting for a few days or longer. I switch to Pri, choke on, key on, neutral check, switch on, Start button. Once she fires I turn it to ON. Don't know that it makes much difference from the ON position but she seems to start quicker that way.

Have used RES once. I try to fill up before I get there.

 

You should only need prime after cleaning the rack, or if the bike has been stood for a good while.

 

As it has a vacuum type petrol tap, if the carbs have been cleaned, they need to be "Pri"med before the engine will fire.

I have read your other post and if your bike runs out of power after about a mile, your vacuum tap might be cattle trucked - like mine. To prove it, try running it in "Pri" but remember to switch back to "On" when you stop.

If you don't, it may be possible to fill the crankcase with petrol - if the carbs are leaky!

 

hey markie! a fellow englishman! not many on here! (although, truly I'm a Cornishman!)

Its not after distance that the power goes, its just got no 'top-end'.
Thanks for the info tho

I've gotta watch out I'm keeping my judgements in context with a 28 yr old bike - I'm used to modern kit!

 

Hmmm... There are people on the forum with much more carb knowledge than me but I would have thought the k&ns and exhaust mods would affect the low speed running more than high.

My bike (In the garage at the moment) was weak at low speed as a previous owner used a pair of tights for an air filter - see my gallery for the proof!

 

I didn't read the other thread but with pods and a header you have made two mods that will make the bike run leaner.
Could be you are just leaning out at higher rpm's.

 

+1 with thehound,
just pull the plugs and look at the bottom end of the ceramics.
if light grey or clean...your running lean.
tan or dark grey is great, the blacker the richer.
the bottom will only match the top if idle and WOT are both running
with the prop mixture.