Stuck Fuel Cap

[Bob_Roller]

I was working on the '84 LS today (only 95 F. (35 C.) in the garage), trying to get the fuel cap off, tried the rope over the garage door rail, and pulling on the rope, no success .

I did a search for stuck fuel cap, and came up with nothing useful .

Exactly where do you drill a hole from the top, and then place a pin, or other suitable part, to stop the cap from spinning ?

How long does the pin need to be ?

[bruce_launceston]

Hi Bob

From memory (and it was an awfull long time ago that I did mine) the pin goes from the side, through an existing hole just above the threaded section. I really don't know if you can do that untill you get the cap off. You might be able to slide a flat screwdriver under the lip of the cap and tap it to get the lower part to turn, might help to spray some CRC in there to help unbind the thread.

I remember it was a PITA and I slightly damaged the plastic lip on the outer edge of the fuel cap trying to get it off.

I read that some people are driving a number of self tapper screws through the side but from my experience that is probably overkill, my single pin or nail or whatever I used has been in there for about 20 years without causing any further trouble.

Keep at it and good luck.

Bruce

[Bill Conquest]

Bob - This happened to me, too. I got the info on snobum's site on what to do.. basically take off the outer plastic skirt and there are three holes in the side of the cap equidistant apart - find a thin nail, I used a 15 gauge finish nail, i think..push it thru one of the holes & turn the cap 'till you feel it engage a corresponding hole in the underneath part of the cap. It should then hold the 2 parts together & unscrew. You can then screw the 2 parts together using stainless screws, from underneath up, making them one & re-use the cap.. no more locking, though. It worked for me & i've used my cap successfully for the last 3 years.
Bill Conquest

[montmil]

Bob, Hit Snowbum's site for his f-u-l-l explanation.  Monte

[Bob_Roller]

There are two different caps one with the BMW logo, and one without, I have the later model, no holes under the ring, I removed it just to be sure .

My only other option, is to drill a hole from the top, and put in a pin, or a self tapping screw .

I plan on using a drywall screw .

[Lucky_Lou]

I was told the cap with the BMW logo you drill throught the "M" if theres no logo you may have to go compair the position with one with it.
Lou

[bruce_launceston]

Hi Bob, I wouldn't drill through the top, I have the same cap as yours, give me a few hours and at lunchtime I will have a look at it and see if I can give any more info on where I put the pin.

[Bob_Roller]

I went to Snowbum's BMW site, and he states that you can drill through the top on the later cap, but you need to go just about all the way through the cap .

I think I have found a suitable countersunk screw at work, it is long enough to go through the entire cap, and then put a nut on the fuel side .

I don't intend to start on this until Monday, so any comments before then are welcome .

[R65_Mark]

Bob,

I've got a drilled one that I can take apart and photograph.  Look for some images that I'll post tomorrow - or the day after if I forget (oops).  Mark

[bruce_launceston]

Hi Bob
I had a good look at my cap tonight. There is no sign of any pin, I am sure I drove it through one of the 2 existing holes in the side of the threaded section of the cap, just above the thread. The threaded lower part of the cap turns back and forth about 1/4 inch.
I can still see the screwdriver marks underneath the plastic lip from where I levered the cap off when it got stuck.
As I said above, if you can persist and get the cap off you can then fix it permanently without drilling any holes and adding any screws where they will be seen.

[R65_Mark]

All, Images of my "drilled" cap below.  You can see that it has been attacked many times.  I think the real secret to getting the cap part off the threaded section is confident brute force.  If it is on the tank on  the bike, a rope through the cap "flap" and a very good tug might do it, but I've never had a cap stuck on the bike and had to do this.  Off the bike, a pair of opposed screwdriver/levers under the cap and it pops off.  Mark

[Bob_Roller]

Thanks for the pictures .

I put a light oil in the lock assembly on Tuesday, tomorrow, I'm going to give the rope method one more try, if it doesn't work, then I'll  drill all the way through the cap, according to Snowbum's site, you can drill a hole where the fold down part of the cap will cover it up .

I've got a 2.5 inch stainless screw, and a self locking nut, I'm sure this will solve the problem once and for all !!!!!!!!!!!!!!!!

[montmil]

Bob, Don't forget to slosh out the metal bits from the tank after getting the cap off. Probably needs a bath anyway.    Monte

[Bob_Roller]

There's still a bit of old fuel in the tank, I'll put some alcohol in there and get the metal shavings out .

This tank does have the metal mesh screen over the inlet tubes of the fuel tap, I'm not getting too concerned, if a few metal shavings are still in there .

[R65_Mark]

Bob, In case it is not clear, the groove/rebate in the body “A” has a counterpart in the cap “B” that, when pressed together as an assembly, joins the parts yet allows the cap to rotate.  When it is working correctly, the key mechanism can be used to lock the two parts together.  Drilling and screwing the parts together does the same as the latter, but permanently.  I think the reason for the specific measurements I have seen is so that the hole that is drilled clears the bosses/ridges cast into the cap “C”.  It might be possible to drill as you suggest so that the effects are hidden by the cap's folding lever, which would be in the area “O”.  The cap pictured is one that was already “customized” when I bought my R65 and is a spare (I bought a new one), so I’d be happy to do some experimenting if you like and can wait (I’m off for a relatively chilly - high 50’s low 60’s - but sunny trip to the north Georgia Mountains for a few days).  Good luck.  Mark