[inamaze]

So, being new to the riding thing, I'm having a blast.

My lean-fu is strong, my shift-fu is strong, and now my switch-to-reserve-on-the-fly fu is strong too.

But the thing is, when the main tank runs out, the engine starts sputtering and has no power... but it stays like that for much longer than I expect. Today I wanted to see how far it would go, several blocks, and it didn't die...

I figured that when the main tank runs dry, then the feed tube will run dry, then the carb float bowls will run dry... and the engine should stop dead.

Is there some reason the engine still has enough fuel at the end of the main tank to allow it to stagger along for a while?

I'm glad for it, but I'd like to hear the answer if someone knows before I tear apart the tank to find out.

 

[A2rider]

So you're saying that with the petcock on the "ON" position, it still runs, albeit roughly? And you want to know when to put it to "Reserve"? Or are you trying to figure out if somehow the bike is still getting gas, when it should be dry because you haven't switched it to "Reserve" yet?

 

[inamaze]

So you're saying that with the petcock on the "ON" position, it still runs, albeit roughly? And you want to know when to put it to "Reserve"? Or are you trying to figure out if somehow the bike is still getting gas, when it should be dry because you haven't switched it to "Reserve" yet?

Yes, in the ON position, the tank runs the "main" empty and starts sputtering. It runs way rough and with no power, but it does run for a fairly long time. I would expect it to be pretty sudden death since when the gas stops feeding up the jet, the engine dies...

Is it somehow getting a little gas when the main is empty? Cool design if that's the case since it gives you time to switch over before it dies and you have to restart...??

 

[A2rider]

OK, got ya now! I forgot what bike you have. Please post it, and hopefully someone will see this and help out. I don't have a clue why it's still running. Every carbed bike I've had will stop when the main runs out. Weird!

 

[Box]

Generally you don't have an actual separate tank, the petcock just changes which part of the fuel pickup it is using.
So, when the fuel gets low enough for the bike to run out, the fuel is still sloshing about and some of it will get into the top end of the pickup allowing it to run longer, albeit badly.

 

[inamaze]

Generally you don't have an actual separate tank, the petcock just changes which part of the fuel pickup it is using.
So, when the fuel gets low enough for the bike to run out, the fuel is still slopping about and some of it will get into the top end of the pickup allowing it to run longer, albeit badly.

That makes sense. I guess next time it happens I'll stop and see how long it runs without slosh... my guess is not very long.

 

[brother]

It's not nice to torture you engine like that, it will puke a valve at you.

 

[aftermath4788]

on my 250 when i run out of gas on the main tank she will start to lose power and slow down very gradually at that point im screwed unless i switch to reserve. once i notice a change in power i have all of about 100 feet before she dies out on my doing 70mph with a big truck behind me. lol not fun

 

[NCDave]

my Vulcan dies more quicly than my Suzi VX did when nearing reserve. When the Vulcan sputters, I have to move quick.

 

[likearock4x4]

Best choice... don't let it get that low.... :wink: Then you don't have to worry about that truck making a larger hole somewhere... :lol:

 

[inamaze]

I think it has to be the "slosh effect" (and I'm coining the term).

In my case, I have a new speedo, and for the last 3 tanks messed up the trip odometer so I couldn't count miles. Also, my riding has been in town, so plenty of stop and go, turns, etc. giving plenty of opportunity for slosh.

Thanks for the replies

 

[kawah1c]

I hope it's not a 2 stroke...

 

[JimmyD]

If you're cruising at a moderate pace the gas in your floatbowls will last a very long time. Smaller bikes will run on fumes for quite a clip, but you'll notice that once you open the throttle you'll get no response. You might not be stuttering yet but you're close.

As someone said, it doesn't take long running a bike excessively lean to cause disastrous results.