Petrol Smell

[Mike Gough]

Sorry seem to have originally put this in wrong section....

Just recently started to get a slight wiff of petrol from my 1200GS. I use the bike 4-5 times a week. No petrol leaks that I can detect.
Anyone had experience of the same, or any ideas.
Mike

 

[PhilBolton]

I've got the same problem, though only when riding, particularly when the tanks full(ish) and/or on bumpy going.
I recently had the tank top off to drill an air hole in the neck to aid filling, and maybe the seal between the filler neck and tank is not seated probably - it's abugger to get in. But as the smell didn't appear until several tanksfull after I did the job, I'm not convinced. I'll have to take it to bits again to be sure.

So, how old's yours?
Has the tank filler neck been in bits lately?
Do any of the more experienced folk know of anything?

Phil

 

[Mike Gough]

Phil, mines an 06, bought it a couple of months ago with only 1600 miles on the clock, no mods.
How painfull is the the filling though!!

 

[Deleted account 211025001]

I've had it happen a few times, always after filling the bike. The filler cap needs a lot of pressure to close it properly and on a few occasions I've thought I closed it properly, smelt petrol whilst riding along and upon checking realised the cap was not quite closed - could be the reason on your bike

Andres

 

[PhilBolton]

Mike, trying to fill the tank completely can result in an eruption of petrol when it's nearly full. You've probably experienced this yourself!
Quite a few posts about it on here.
Caused by snug(ish) fit of nozzle in rubber sleeve and air trying to get out.
Solution is to drill a small hole in the filler neck, below the cap seal, to allow air out. And also to remove the rubber sleeve at the bottom of the filler neck.
I'm just trying the hole at the moment, but I think the rubber sleeve will be coming out soon.
The air hole does allow better filling of the tank though.

Andres - Yes, I've done that as well, but this isn't that ( does that make sense?)

Phil

 

[terayon]

Phil you should have tried the rubber seal removal first, i did and it now takes half the time to fill up and can do it in one go.
All with out the drilling

 

[PhilBolton]

You're probably right, but the hole does allow you to get a bit more in the tank 'cos it allows the air out of the top of the tank above the bottom of the filler neck. We're probably only talking about a litre or less - but that's another 10 miles or more.
(what I'd really like is an Adv tank, but that's another story!)

Phil

 

[terayon]

Since pulling the rubber out, I've consistently got another 15 miles out of my tank. As 's say "every little helps"

 

[PhilBolton]

Interesting!!
Maybe because when fitted the rubber sleeve extends below the metal tube of the neck? and removal thus allows more air out/petrol in?
So the hole will mean even more air out/petrol in?

Phil

 

[Happyhenry]

Sketch Please

This sounds interesting, but I can't quite picture what you're talking about. Does the filler tube stick too far down into the tank and where does the rubber thingy come into it? Can someone please sketch a simple section so we can all join in?

 

[PhilBolton]

At the bottom of the steel filler neck is a black rubber sleeve - it's purpose, I think, is that a diesel pump nozzle is fatter than an unleaded nozzle, so a diesel nozzle is not supposed to fit in.
The tank filler neck extends some 2 inches into the tank, so filling "to the brim" inevitably leaves an air gap at the top of the tank. This may be to allow for expansion of the fuel, (it's cooler in a tank underground than in your tank in sunshine and over a hot engine).
Removing the the rubber sleeve effectively shortens the filler neck -smaller air gap - and alleviates the blowback of petrol when the tanks nearly full, 'cos it's now a bigger hole.
The air gap can be further reduced by putting a small hole in the neck to allow air out. The downside of this is - if you fill and park up, the fuel may expand and come out of the overflow.
Clear?

Phil

 

[Tman]

+1

I've had it happen a few times, always after filling the bike. The filler cap needs a lot of pressure to close it properly and on a few occasions I've thought I closed it properly, smelt petrol whilst riding along and upon checking realised the cap was not quite closed - could be the reason on your bike

Andres

Whenever I smell gas, I check the cap and though it looks closed, it is actually still open.

 

[PhilM]

you should have tried the rubber seal removal first, i did and it now takes half the time to fill up and can do it in one go.
All with out the drilling

I've done this to my one. Now there is a faint whiff of petrol, I normally notice it in my garage, nothing to worry about though.

 

[barneydinosaur]

The fuel filler is not really a triumph all round. I recon the cap is on backwards and mine often does not shut convincingly first time.

Even with the rubber thing removed you still need to be careful when filling near to the top and with the nozzle nearly out of the tank: the lip to which the rubber thing attaches is, I've found, quite efficient at returning petrol if the jet of fuel catches it. The prospect of an eye full of petrol does not appeal.

 

[Terzikat]

Glad its not just mine then

I've noticed a petrol smell around mine a few times when its been in the garage and the air is still. I thought I had a small leak somewhere, but maybe its just a "characteristic" of the bike

 

[beacon]

I've had it happen a few times, always after filling the bike. The filler cap needs a lot of pressure to close it properly and on a few occasions I've thought I closed it properly, smelt petrol whilst riding along and upon checking realised the cap was not quite closed - could be the reason on your bike

Andres

I,m REALY glad I,m not the only one this has happend to, I thought I was going up in flames as when I put the front brake on the tank empted out over the front, and the wind blew it back over me not nice! now I always check that cap.

Chris

 

[PhilBolton]

I finally got round to sorting out my smelly petrol problem - it was the rubber seal between the filler neck and the tank, as I suspected, so it was entirely self inflicted.
I had it all in bits again to fit a tanktop rack that I've had for years.

Interesting point (to me anyway):-
the six screws in the cap ring go through the filler neck flange and fix into tapped brass inserts moulded into the plastic tank - very fiddley job to get it all back, especially with the three rubber wedges that secure the tank cover,
BUT the PCD (pitch circle diameter) of the holes in the filler neck is not the same as the PCD of the brass inserts in the tank and the cap ring, it's slightly smaller, so the neck binds on the screws. Thus making assembly further complicated.

Pisspoor design!

Phil
Anyway, my petrol smell was due to my own previous incorrect assembly of the seal, and this was evidenced by petrol spill stains on the tank sides after I took off the tank covers.
It may simply have been my reluctance to tighten the six screws enough to compress the seal, for risk of stripping a thread in the brass inserts.
Certainly this time I tightened (gingerly) until I felt each one "bottom out", and no more smells.
And I've now taken out the silly rubber sleeve.

 

[cockneyjanner]

What is involved to remove the rubber sleeve? Is it a simple "pull it out job", or does the filler neck need to be removed?

 

[Pukmeister]

I managed to hook mine out with my index finger.

It takes a firm pull to do it.

(A serious opportunity for double-entendres with this subject.)

 

[PhilBolton]

yes, just pull it out - it locates on a small lip at the bottom of the filler neck.
Just be careful not to drop it in.

Phil