Evo petrol fountain :eek:

SunEye · 13-11-2012, 10:45 AM

For a while now I've been having problems with a build up of pressure in the fuel tank when the engine gets really hot i.e. running with the temperature gauge one or two bars from the top for a significant amount of time. When you then open the petrol cap to refuel there is a sudden release of pressure from the tank and you can see the tank panels move back into place because the fuel tank has expanded so much it has pushed the tank panels out.

The tank appears to be venting ok because you can see vapour coming from the end of the vent pipe under the bike, although I have not checked this when the engine has been really hot. When I had the bike serviced at Pro Twins recently they couldn't find any obvious reason for the problem.

On Sunday I rode from Horsham to the Ace Cafe (40 miles) on a full tank of fuel. Due to the wonderful London traffic my Evo's temperature gauge was reading one bar from the top around most of the south and north circulars so I thought I'd see if after its service I still had the tank pressure problem when I got to the Ace Cafe. So when I parked up I opened the petrol cap and was met with the familiar release of pressure from the tank combined with the return to true shape of the tank panels. However immediately following that came a new experience. A fountain of petrol coming out of the tank

After I'd lost about half a litre onto my bike and the Ace Cafe car park I managed to close the petrol cap on the geyser which my fuel tank had become.

So the bike is going to Pro Twins tomorrow where hopefully I'll be able to demonstrate my newly discovered Evo petrol fountain to them after riding around Godstone for half an hour at walking pace to build up some extra heat in the engine.

J.P · 13-11-2012, 10:49 AM

Jeez never had or heard of that problem before.

13-11-2012, 10:55 AM

mmmm weird, sound like its presurising the tank, can the fuel pump be leaking within the tank therefore presurising it???

Will scratch head a little longer

Char · 13-11-2012, 10:56 AM

I nearly had that after fitting my fuel filler cap back on back to front after taking if off for powder coating -

You sure do have some sh*t luck

13-11-2012, 11:01 AM

Eeek! That doesn't sound good at all...

For what it's worth, I've only ever seen 4 bars on the temp gauge on mine (in traffic), but most of the time it's on 3 bars... It seems to keep fairly cool on its own.

13-11-2012, 11:06 AM

I regularly run 3 or 4 bars in my central London commute, sometimes 5 and on ocassion 6 bars during summer, but have not experienced or noticed what you've described. Hope you get it resolved.

13-11-2012, 11:50 AM

Would appear that the tank isnt venting as it should? Would get it sorted before it seam-splits and drops gallons of petrol onto a hot engine...

Try removing the silver one way valve from your tank breather pipe - have you had this valve off before? Will only work one way, make sure it isnt backwards! Try blowing through it both ways to check it works OK.

Long shot but - have you POR-15'd your tank? Any sealant treatment or similar? Would bung the breather hole up if not kept clear?

Too much pressure in the return line going back to the tank?

13-11-2012, 12:05 PM

It doesn,t really matter what the source of the pressure is, the fact is that the tank is NOT venting.

utopia · 13-11-2012, 12:20 PM

Should the tank vent under positive internal pressure, or does the design merely avoid a build up of vacuum as fuel is pumped out....?
Instinct says it should vent both ways, but I haven't actually studied the system.
If a high pressure can develop inside the tank, then I guess you would expect the return from the fuel pump to struggle.

Didn't Capo do a tech piece on injection fuel systems a while back ? That may contain a clue or two.

jerry · 13-11-2012, 02:22 PM

Gasohol warped tank = closed pressure vents, has happened to bikes in USA and thailand tanks eventually explode

Albie · 13-11-2012, 03:53 PM

Quote:

Originally Posted by 470four

Long shot but - have you POR-15'd your tank? Any sealant treatment or similar? Would bung the breather hole up if not kept clear?

Why would he rust proof a plastic tank ?

Rally · 13-11-2012, 06:31 PM

As said before, the problem is obviously the tank vent not working. Put an airline against the rubber sealed hole under the fuel cap and pressurise it. If it is blocked, the high pressure should unblock it. If it isn't blocked, it will do it no harm to try it.

As Char said, if the petrol cap is fitted backwards, it blocks the air vent when shut. Heat from the engine will make the fuel expand, which will give you the fountain with no vent working.

SunEye · 13-11-2012, 08:03 PM

Thanks for your comments and thoughts on my Evo's problem.

My understanding of the vent is that it should relieve the build up of pressure in the tank. The fact that the vent works ok when the engine is cool/warm (you can see petrol vapour coming out of the end of the vent pipe under the bike), but I get pressure build up when the engine gets hot would seem to indicate that when the engine gets hot something expands and restricts the venting. I have checked the routing of the vent pipe and it is not pinched or kinked anywhere.

I am sure that Pro Twins will get to the bottom of the problem. They have already spoken to Ducati UK about it who have said that it is not a problem that they have come across before. ProTwins will have my bike until the issue is resolved and as I have no trips planned they can take their time and be certain it is fixed before giving it back to me. I would like to think that with the bike being only 4 months old that this will be sorted out under warranty.

I'll let you know the diagnosis.

Albie · 13-11-2012, 08:06 PM

Quote:

Originally Posted by SunEye

Thanks for your comments and thoughts on my Evo's problem.

My understanding of the vent is that it should relieve the build up of pressure in the tank. The fact that the vent works ok when the engine is cool/warm (you can see petrol vapour coming out of the end of the vent pipe under the bike), but I get pressure build up when the engine gets hot would seem to indicate that when the engine gets hot something expands and restricts the venting. I have checked the routing of the vent pipe and it is not pinched or kinked anywhere.

I am sure that Pro Twins will get to the bottom of the problem. They have already spoken to Ducati UK about it who have said that it is not a problem that they have come across before. ProTwins will have my bike until the issue is resolved and as I have no trips planned they can take their time and be certain it is fixed before giving it back to me. I would like to think that with the bike being only 4 months old that this will be sorted out under warranty.

I'll let you know the diagnosis.

Mine does hiss in summer more than anything. But I dont use as much as yourself so cannot really comment. Never had a fountain mind only in the pond. Hope Pro Twins sort it out soon.

14-11-2012, 05:30 PM

Quote:

Originally Posted by Albie

Why would he rust proof a plastic tank ?

Quote:

Originally Posted by jerry

Gasohol warped tank = closed pressure vents, has happened to bikes in USA and thailand tanks eventually explode

As above, have heard of people sealing plastic tanks against ethanol petrol? Originally not designed to cope with this chemopetrol as such and will swell/buckle etc?

Not pretty.

13-11-2012, 10:45 AM	#1
SunEye Registered User Join Date: Nov 2010 Location: Bognor Regis Bike: Other Ducati Posts: 589	Evo petrol fountain :eek: For a while now I've been having problems with a build up of pressure in the fuel tank when the engine gets really hot i.e. running with the temperature gauge one or two bars from the top for a significant amount of time. When you then open the petrol cap to refuel there is a sudden release of pressure from the tank and you can see the tank panels move back into place because the fuel tank has expanded so much it has pushed the tank panels out. The tank appears to be venting ok because you can see vapour coming from the end of the vent pipe under the bike, although I have not checked this when the engine has been really hot. When I had the bike serviced at Pro Twins recently they couldn't find any obvious reason for the problem. On Sunday I rode from Horsham to the Ace Cafe (40 miles) on a full tank of fuel. Due to the wonderful London traffic my Evo's temperature gauge was reading one bar from the top around most of the south and north circulars so I thought I'd see if after its service I still had the tank pressure problem when I got to the Ace Cafe. So when I parked up I opened the petrol cap and was met with the familiar release of pressure from the tank combined with the return to true shape of the tank panels. However immediately following that came a new experience. A fountain of petrol coming out of the tank After I'd lost about half a litre onto my bike and the Ace Cafe car park I managed to close the petrol cap on the geyser which my fuel tank had become. So the bike is going to Pro Twins tomorrow where hopefully I'll be able to demonstrate my newly discovered Evo petrol fountain to them after riding around Godstone for half an hour at walking pace to build up some extra heat in the engine.

13-11-2012, 10:49 AM	#2
J.P No more Monster... Join Date: Jan 2007 Location: London Bike: Other Not a Ducati Posts: 4,326	Jeez never had or heard of that problem before. __________________ J.JP ------------------------------- My Mum says, there's no such thing as Monsters.

13-11-2012, 10:56 AM	#4
Char We're all mad here Join Date: Aug 2010 Location: Wiltshire Bike: Other Not a Ducati Posts: 1,536	I nearly had that after fitting my fuel filler cap back on back to front after taking if off for powder coating - You sure do have some sht luck __________________ If you don't know where you are going any road can take you there*

13-11-2012, 02:22 PM	#10
jerry Old Git Join Date: May 2006 Location: Cricklade Bike: Multiple Monsters Posts: 2,816	Gasohol warped tank = closed pressure vents, has happened to bikes in USA and thailand tanks eventually explode __________________ MONSTERMAN

13-11-2012, 10:55 AM	#3
pegboy Guest Posts: n/a	mmmm weird, sound like its presurising the tank, can the fuel pump be leaking within the tank therefore presurising it??? Will scratch head a little longer

13-11-2012, 11:01 AM	#5
neilo Guest Posts: n/a	Eeek! That doesn't sound good at all... For what it's worth, I've only ever seen 4 bars on the temp gauge on mine (in traffic), but most of the time it's on 3 bars... It seems to keep fairly cool on its own.

13-11-2012, 11:06 AM	#6
simontt Guest Posts: n/a	I regularly run 3 or 4 bars in my central London commute, sometimes 5 and on ocassion 6 bars during summer, but have not experienced or noticed what you've described. Hope you get it resolved.

13-11-2012, 11:50 AM	#7
470four Guest Posts: n/a	Would appear that the tank isnt venting as it should? Would get it sorted before it seam-splits and drops gallons of petrol onto a hot engine... Try removing the silver one way valve from your tank breather pipe - have you had this valve off before? Will only work one way, make sure it isnt backwards! Try blowing through it both ways to check it works OK. Long shot but - have you POR-15'd your tank? Any sealant treatment or similar? Would bung the breather hole up if not kept clear? Too much pressure in the return line going back to the tank?

13-11-2012, 12:05 PM	#8
Dookbob Guest Posts: n/a	It doesn,t really matter what the source of the pressure is, the fact is that the tank is NOT venting.

13-11-2012, 12:20 PM	#9
utopia No turn left unstoned Join Date: Jun 2010 Location: leicester Bike: M750 Posts: 4,545	Should the tank vent under positive internal pressure, or does the design merely avoid a build up of vacuum as fuel is pumped out....? Instinct says it should vent both ways, but I haven't actually studied the system. If a high pressure can develop inside the tank, then I guess you would expect the return from the fuel pump to struggle. Didn't Capo do a tech piece on injection fuel systems a while back ? That may contain a clue or two.

13-11-2012, 06:31 PM	#12
Rally Taking life easy........ Join Date: Feb 2010 Location: Wiltshire Bike: Other Not a Ducati Posts: 1,969	As said before, the problem is obviously the tank vent not working. Put an airline against the rubber sealed hole under the fuel cap and pressurise it. If it is blocked, the high pressure should unblock it. If it isn't blocked, it will do it no harm to try it. As Char said, if the petrol cap is fitted backwards, it blocks the air vent when shut. Heat from the engine will make the fuel expand, which will give you the fountain with no vent working.

13-11-2012, 08:03 PM	#13
SunEye Registered User Join Date: Nov 2010 Location: Bognor Regis Bike: Other Ducati Posts: 589	Thanks for your comments and thoughts on my Evo's problem. My understanding of the vent is that it should relieve the build up of pressure in the tank. The fact that the vent works ok when the engine is cool/warm (you can see petrol vapour coming out of the end of the vent pipe under the bike), but I get pressure build up when the engine gets hot would seem to indicate that when the engine gets hot something expands and restricts the venting. I have checked the routing of the vent pipe and it is not pinched or kinked anywhere. I am sure that Pro Twins will get to the bottom of the problem. They have already spoken to Ducati UK about it who have said that it is not a problem that they have come across before. ProTwins will have my bike until the issue is resolved and as I have no trips planned they can take their time and be certain it is fixed before giving it back to me. I would like to think that with the bike being only 4 months old that this will be sorted out under warranty. I'll let you know the diagnosis.