Fuel tank without key to the cap...how do I remove or open the cap?

Hi Guys,

I just picked up a 1983 Yamaha xj750 Seca with the intention of using it for parts, but it's pretty decent so I'm thinking of getting it up and running (along with my 82 xj750 Maxim and my 85 xj700n Maxim).

Wanted to see if it runs, so I put in a battery, turned on the fuel and cranked it over. I have the key to the ignition, but somewhere down the line the fuel tank cap must have been replaced and it must be another key as this one won't work. The guy I bought it from will not respond to my calls and emails, so I think he was aware of this and is avoiding me.

None-the-less, I'm hoping the collective minds on this great forum will be able to come up with a solution. Other than drilling a gigantic hole in the cap to remove it that is...

Not that I mind making large holes in things or breaking stuff, that's always fun...but not overly productive at times...

Thanks in advance

Gord

 

welcome to the forum. without the key, there are only two options. jamb a regular screwdriver where the key would go and use a pair of vice grips to force it open ( I have done this), or drill out the lock cylinder. the latter will allow you to rebuild the main body of the cap but either way you will need another cap for parts. they aren't hard to come by.

FU

 

The quick answer is if you don't want to go to a locksmith you can still try to pick it but you'd need a lot of patience and the proper tools. If you can carefully pry the chrome cover off (tabs are at the hinge end) you can at least see which one of the 4 types of master keys it needs, but you would still need the code.
Does the bike have a helmet lock? does it have the same problem, different key that the ignition? If yes and yes, the ignition may have been replaced but the gas cap and helmet lock are an original match. I'm not sure, but the helmet lock, if you can remove it, might have a code stamped on the back. Bring that code to the locksmith with the removed helmet lock, and for $10-$15 they can cut a key for that. With luck, it fits the gas cap as well.

Otherwise, like cyclenoob says, consider the tumbler as expendable and pry it open. Another replacement gas cap is easy to source, and if you still want everything to open with one key there is a way to do that too - PM me for details if/when you get to that stage.

One word of caution - if the bike sat outside for a long time, even the correct key may not allow a seized cylinder to turn - happened to me. With lube and patience, I finally got mine open.

I have a matching set of helmet lock, gas cap, and ignition but unfortunately they are for a Seca 550 otherwise I'd offer them up to you as you are not too far away for shipping.

 

Thanks CN, Looks like I get to have a bit of fun wrecking things after all I'll follow up with a post on how it goes.

-Gord-

 

What CN and 4nik8r said or take the tank to a old school locksmith nicknamed "Peanut" like i did and have him pick the lock and hand file a key.

Gary H.

Post edit: @4nik8r... you type too fast.

 

Thanks 4nik8r,

I'll try that before wrecking it, and I'll see if the ignition key works with the helmet locks as you mentioned. I have been squirting WD40 into the key slot for the last couple of days and wiggling the key (carefully as to not break my only working ignition key for the bike). It feels quite firm as though it is the incorrect key.

I see you are (relatively) close by (Ottawa is 275 km east of me), too bad, that would have been a quick solution to swap out everything.
Oh well, no pain no gain. I'll see how it goes in the am and post the results.

Thanks again CN and thanks for taking the time to respond 4nik8r.

 

Thanks Gary, we need more "peanut"s out there. Love the old school guys who can work miracles with nothing If I find a guy like that in eastern Ontario I'll post it.

 

You're welcome. I have a parts 550 Seca that I'm slowly divesting; if you find later need other parts there are a few that are interchangeable between the models (some electrics, small parts, engine covers, etc.)

 

P.S. If you lose your key(s), or obtain a used gas tank that still has a (locked) cap on it but with no key, then it may be time for you to learn the ancient art of lock-picking:

http://www.capricorn.org/~akira/home/lockpick/

 

Thanks Chacal, with that info I'm headed over to pick that night deposit box at the bank. Then I can buy all the gas caps I want! Bwahahahaha!!

 

Okay, so the key works in the ignition and the helmet lock, so I'm thinking the cap was changed at one point. The fuel tank is empty...could it be that the reason this seller sold the bike for a low price is because he couldn't get fuel into it (after losing the key)? Nah...couldn't be that lucky...

 

Does the key actually fit the slot, but simply does not turn the tumbler, or does the key not even fit in the slot? There are 4 different types of key "masters" used on these bikes. If the slot is different than the one for your key, the key will not even slide in and for sure the cap was changed and you'd need to break the tumbler or get it picked.

HOWEVER.....if the key does fit into the slot but simply will not turn - your cap mechanism may simply be seized from age and rust/crud like mine was. If that is the case, there is hope!

Let me know......

 

Hi 4nik8r, The key fits into the slot, just won't turn as you mentioned.

 

Here's a dumb question...Are you pushing down on the cap before trying to turn the key? As 4nik8r stated; rust, corrosion and a deteriorated cap seal may be binding it.

Gary H.

 

Hi Gary,

No such thing as a dumb question, I have been pushing, pulling, twisting and every thing else short of destroying it while trying to turn the key.

But that is a good question, it may have been that simple and I may have missed it, thanks.

 

So here's your next steps:

1. Kroil the snot out of the key slot and insert the key slowly in and out until you can actually feel the key moving the locking pins. Wiggle the key "north-south" a lot and see if you feel the pins placing any pressure against the key as you insert and remove it. If you don't have Kroil use some other good penetrating lubricant.

2. If the key does not feel like its "engaging" any pins, those pins may be stuck and you may need something else in there to loosen them up. Refer back to that lock picking article Len posted for some good tips of what to use (on the last page)

3. If it feels like the pins move but the lock cylinder won't turn (that was my issue), try to first pry off the chrome cap cover, then the chrome cylinder cover (be careful that one bends easily and has a tiny flap with hinge) Now use lost of Kroil/lube around the cylinder mating surface from the top.

4. If this still doesn't allow the key to turn it, now try using your penetrating lubricant with the applicator straw on the nozzle underneath the cap - use a screwdriver or other wedge to gently pry the cap up as far as possible at the 12 o'clock position, then squirt lube in as close to can to the underside of the cap on each side (3 o'clock and 9 o'clock). Try to get lots of lube right in there, don't worry about getting it in the tank. The two locking arms may be crudded up inside not allowing the pinion connected to the cylinder to turn them

Patience is key (no pun intended). Work that key with on and off clockwise pressure; just don't apply so much torque that you bend or (god forbid) break it, and try shifting the pressure north and south in the slot as well as you turn. Eventually, if the key is correct, that cylinder should turn.

Also, is this in a cold garage or a warm workshop? Heat will be your friend. If the bike is in the cold, use a heat source like a hair dryer to locally warm your working area.

 

if you don't have a spare key, you may want to get one made in case you break your original. just a thought.

FU

 

Yes, spent the afternoon looking for a place that would make a spare key for me. Unfortunately the moment you mention "motorcycle" you can see the reaction coming..."oh no, we don't make keys for motorcycles..."

Oh boy.

I live out in the country, not a lot of choices out here. I guess next time I'm heading into the city I'll drop by a proper locksmith shop.

I was out wiggling away at the gas cap with the key and several gallons of WD40 (no "kroil" as this is the first time I've heard of it). North South, in out, too chicken to give it much of a turn without a spare. I did heat it up with a paint peeler (kind've like a hairdryer on steroids) as I'm working in an unheated barn and it's minus 12 Celsius out there today.

I did talk with a guy who said he can make a spare key with only a photograph, I'll see how that goes and if it works I'll post it here.

Thanks again to everyone for your directions and comments, I'm hoping it's simply a stuck cylinder...to be continued once have a spare key in my hand.

- Gord in Ontario -

 

just so you know, you can buy uncut key blanks on ebay for cheap, then have a local locksmith cut it for you. there are some neat ones out of bulgaria. I got this one for my bike...

http://www.ebay.com/itm/Blank-Custo...parel_Merchandise&hash=item56333ff820&vxp=mtr

I even found matching license plate bolts.


FU

 

You are a flamboyant guy CN I'm good with the $2 model.