RE Bullet - Air bubbles in Tank?

Leepower · 28th March 2010, 20:24

My Bullet stalled three-four times today. I took it to the mech. He said that it's due to air bubbles in fuel. I know how to deal with the problem. But is there some way to prevent air bubbles in the first place?

Randhawa · 28th March 2010, 20:54

Possibilities are few.

Fuel pipe taking in air, either from joint at the fuel T or at the carburetor.
Fuel T faulty and taking in air when it's in reserve.

aargee · 28th March 2010, 20:58

I've heard about air bubbles in the fuel line from fuel tank & carbs/FI or between the oil pump & carbs/FI but not in fuel tank. Pls help me understand something here - as the fuel in your tank gets exhausted, the vaccum space should be filled with air otherwise you'll risk the fuel not entering into the carbs/FI. Could you ask/recheck with you mech as how air bubble got in the first place & how to prevent them & post here pls? Thanks.

Leepower · 28th March 2010, 23:25

Even the mech said that air bubbles create trouble when they get in the fuel line or carb and not while they are in the petrol tank. The best solution is to remove the fuel line and let the bubbles out!!!
Now, my troubles started after I tanked up at a petrol pump. And after the mech removed the fuel line and the bubbles escaped, the bike is running very smoothly!!! Oh and one more thing, he told me not to fill up the tank to the brim.

aargee · 29th March 2010, 05:28

^^^haha sounds very strange to me. Why would someone wants to fill to brim? By the meaning of full tank, you only allow to fill such a way that its 90% full & not the brim. Anyway long story short, it shouldn't matter a lot because as fuel moves through the line, the air bubbles also move out. Sorry to say that, I've never experienced this in my last 12-13 years of motorcycle/scooter ownership. On a second look, is there a possibility of adulterated fuel? Try switching to shell & fill it to the brim & make few local trips.

vj_carLover · 29th March 2010, 07:52

Quote:

Originally Posted by Leepower

Even the mech said that air bubbles create trouble when they get in the fuel line or carb and not while they are in the petrol tank. The best solution is to remove the fuel line and let the bubbles out!!!
Now, my troubles started after I tanked up at a petrol pump. And after the mech removed the fuel line and the bubbles escaped, the bike is running very smoothly!!! Oh and one more thing, he told me not to fill up the tank to the brim.

I have two bullets at home. So I sort of know what you mean here.

one - don't fuel to the brim - you must always leave some space on top of the fuel to allow for expansion

two - always shut the fuel line to the carb - while filling fuel - at times this pushes the air in to the carb. Move off the Q and wait it out for like a few seconds, and then open the tap, open the fuel lid, like once, before shutting tightly. I always do this and have been doing this for ages. It works, at least for me.

Cheers

Leepower · 30th March 2010, 20:01

I think it was the bad, adulterated fuel. After it got over and a refill later at another pump, the Bull is running smoothly!!!

28th March 2010, 20:24	#1
Leepower BHPian Join Date: Feb 2010 Location: Maharashtra Posts: 366 Thanked: 78 Times	RE Bullet - Air bubbles in Tank? My Bullet stalled three-four times today. I took it to the mech. He said that it's due to air bubbles in fuel. I know how to deal with the problem. But is there some way to prevent air bubbles in the first place?
	() Thanks

28th March 2010, 20:54	#2
Randhawa Senior - BHPian Join Date: Oct 2007 Location: Brighton Posts: 1,203 Thanked: 361 Times	Possibilities are few. Fuel pipe taking in air, either from joint at the fuel T or at the carburetor. Fuel T faulty and taking in air when it's in reserve.
	() Thanks

28th March 2010, 20:58	#3
aargee Senior - BHPian Join Date: Jan 2010 Location: TSTN Posts: 6,354 Thanked: 10,052 Times	I've heard about air bubbles in the fuel line from fuel tank & carbs/FI or between the oil pump & carbs/FI but not in fuel tank. Pls help me understand something here - as the fuel in your tank gets exhausted, the vaccum space should be filled with air otherwise you'll risk the fuel not entering into the carbs/FI. Could you ask/recheck with you mech as how air bubble got in the first place & how to prevent them & post here pls? Thanks.
	() Thanks

28th March 2010, 23:25	#4
Leepower BHPian Join Date: Feb 2010 Location: Maharashtra Posts: 366 Thanked: 78 Times	Even the mech said that air bubbles create trouble when they get in the fuel line or carb and not while they are in the petrol tank. The best solution is to remove the fuel line and let the bubbles out!!! Now, my troubles started after I tanked up at a petrol pump. And after the mech removed the fuel line and the bubbles escaped, the bike is running very smoothly!!! Oh and one more thing, he told me not to fill up the tank to the brim.
	() Thanks

29th March 2010, 05:28	#5
aargee Senior - BHPian Join Date: Jan 2010 Location: TSTN Posts: 6,354 Thanked: 10,052 Times	^^^haha sounds very strange to me. Why would someone wants to fill to brim? By the meaning of full tank, you only allow to fill such a way that its 90% full & not the brim. Anyway long story short, it shouldn't matter a lot because as fuel moves through the line, the air bubbles also move out. Sorry to say that, I've never experienced this in my last 12-13 years of motorcycle/scooter ownership. On a second look, is there a possibility of adulterated fuel? Try switching to shell & fill it to the brim & make few local trips.
	() Thanks

30th March 2010, 20:01	#7
Leepower BHPian Join Date: Feb 2010 Location: Maharashtra Posts: 366 Thanked: 78 Times	I think it was the bad, adulterated fuel. After it got over and a refill later at another pump, the Bull is running smoothly!!!
	() Thanks