ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-29-2013, 11:21 AM   #1
patrkbukly OP
52 Weeks of warm
 
patrkbukly's Avatar
 
Joined: Sep 2002
Location: Miami, FL.
Oddometer: 846
Fuel tank interchangability

Has anyone had enough bikes in the stable to play around with any tank swapping?

I have a 1980 RT and there is a 1973 /5 tank on Ebay that may have more fuel capacity (which is the goal here).

any possibilities?

here is the ebay link to the tank I would like;
http://www.ebay.com/itm/271276434250...84.m1438.l2649
__________________
You only live once, but if you do it right, once is enough.
Mae West
patrkbukly is offline   Reply With Quote
Old 09-29-2013, 11:47 AM   #2
pjcr12
Stercus accidit
 
pjcr12's Avatar
 
Joined: Jan 2008
Oddometer: 801
Yes, I used a /5 tank on an R80/7 and it looked forking ace, as well as increased fuel capacity. I'd show you a pic of it except I can't because of a combined fuck-up between firefox and photobucket which crashed my computer 3 times
pjcr12 is offline   Reply With Quote
Old 09-29-2013, 11:52 AM   #3
Big Bamboo
Aircooled & Sunbaked
 
Big Bamboo's Avatar
 
Joined: Sep 2010
Location: Big Island of Hawaii
Oddometer: 3,030
The early tank and the later tank have 24 liters, or 6.34 gal. total capacity The early tank will be shorter, front to back, than the later tank, so there will be a gap between it and the seat. Does the '80 still have the master cylinder under the tank? If so, make sure any tank you buy has the space for it. The tank in your link has screw on emblems so it's a very early /5 tank, not sure if it will have that M/C gap. It also has the hinge for the cap on the front. IMO Duncan overprices everything he sells, buyer beware!

Big Bamboo screwed with this post 09-29-2013 at 08:03 PM
Big Bamboo is offline   Reply With Quote
Old 09-29-2013, 11:52 AM   #4
JonnyCash
turd polisher
 
Joined: Jan 2011
Location: Midcoast, Maine
Oddometer: 1,453
It would work, as long as you don't have an under-tank master cylinder, which I don't think you would. The biggest issue I can see here is that you should not pay this guy anywhere near that much for that tank. That guy always has his stuff priced at about double the going rate. Shit, I just sold the same tank on an ebay auction for $60. It needed more work than that one, but it was definitely not junk.
__________________
I wouldn't bring her home to Mama, but Mama ain't home tonight.
JonnyCash is offline   Reply With Quote
Old 09-29-2013, 11:55 AM   #5
pjcr12
Stercus accidit
 
pjcr12's Avatar
 
Joined: Jan 2008
Oddometer: 801
pjcr12 is offline   Reply With Quote
Old 09-29-2013, 12:09 PM   #6
Rob Farmer
Beastly Adventurer
 
Rob Farmer's Avatar
 
Joined: Aug 2002
Location: Loughborough, Leicestershire. England
Oddometer: 5,236
Quote:
Originally Posted by pjcr12 View Post
Can't beat something thats built in a proper shed
Rob Farmer is offline   Reply With Quote
Old 09-29-2013, 12:17 PM   #7
Big Bamboo
Aircooled & Sunbaked
 
Big Bamboo's Avatar
 
Joined: Sep 2010
Location: Big Island of Hawaii
Oddometer: 3,030
Quote:
Originally Posted by pjcr12 View Post
Your center stand is sacked...
Big Bamboo is offline   Reply With Quote
Old 09-29-2013, 12:23 PM   #8
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,592
The /5 bikes had mechanical brakes on all models. Beginning in 1974 with the /6 bikes most models got hydraulic brakes up front. The master cylinder for the front brake is under the tank on a 1980 bike. You have Ate front brakes? And this is the type of gas tank you have?



May not be that color but that is the type of tank you have? The /5 tank will not fit if you still have the MC under the current tank. You will also have to use a /5 or /6 seat with the /5 tank because the /7 seat will leave a gap between tank and seat.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 09-29-2013, 12:45 PM   #9
Big Bamboo
Aircooled & Sunbaked
 
Big Bamboo's Avatar
 
Joined: Sep 2010
Location: Big Island of Hawaii
Oddometer: 3,030
Quote:
Originally Posted by disston View Post
The /5 bikes had mechanical brakes on all models. Beginning in 1974 with the /6 bikes most models got hydraulic brakes up front. The master cylinder for the front brake is under the tank on a 1980 bike. You have Ate front brakes? And this is the type of gas tank you have?



May not be that color but that is the type of tank you have? The /5 tank will not fit if you still have the MC under the current tank. You will also have to use a /5 or /6 seat with the /5 tank because the /7 seat will leave a gap between tank and seat.
Actually, around 1973 the large /5 tanks started coming with the gap for the M/C, and all the small tanks have it. Read Duanes excellent article on it: http://w6rec.com/duane/bmw/tank/index.htm
Big Bamboo is offline   Reply With Quote
Old 09-29-2013, 01:52 PM   #10
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,592
Quote:
Originally Posted by Big Bamboo View Post
Actually, around 1973 the large /5 tanks started coming with the gap for the M/C, and all the small tanks have it. Read Duanes excellent article on it: http://w6rec.com/duane/bmw/tank/index.htm
I have a 1973 large tank that has stick on emblems instead of screw on. It looks exactly like a /6 tank but it has a /5 tank bottom and does not fit my /6 bike. This may not be the case with small tanks but I was bit once already by a large /5 tank and want to warn those looking that it is not likely the tank will fit if the master cylinder is still on the frame.

To OP,
Several times we have mentioned this issue about the master cylinder. Your bike was made with the master cylinder on the frame under the tank. It is a popular mod to put a later model master cylinder on the handle bars and then you don't have a need for the large space of a /6 or /7 tank.

If your bike is stock and still the way BMW built it then the tank you have been looking at doesn't fit your bike.

Pretty simple really.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 09-29-2013, 02:18 PM   #11
Big Bamboo
Aircooled & Sunbaked
 
Big Bamboo's Avatar
 
Joined: Sep 2010
Location: Big Island of Hawaii
Oddometer: 3,030
Here is the large tank with the stick on emblems and forward hinge that came off my 1973 R75/5: To the OP, note the gap for the master cylinder. The tank Duncan is selling does NOT have this gap:
Big Bamboo is offline   Reply With Quote
Old 09-29-2013, 07:31 PM   #12
patrkbukly OP
52 Weeks of warm
 
patrkbukly's Avatar
 
Joined: Sep 2002
Location: Miami, FL.
Oddometer: 846
Ok so its actually not larger capacity?

Thanks Big Bamboo,
And since I have that master cylinder under the tank, unless I move it to the throttle mount master I am SOL?

And yes Disston that does look like the tank I have.

Speaking of....can I install the throttle mounted master cylinder like my PD has or not enough umpf to close those 2 calipers?

Got to be an easier way to get more fuel in this thing.
__________________
You only live once, but if you do it right, once is enough.
Mae West
patrkbukly is offline   Reply With Quote
Old 09-29-2013, 08:09 PM   #13
Big Bamboo
Aircooled & Sunbaked
 
Big Bamboo's Avatar
 
Joined: Sep 2010
Location: Big Island of Hawaii
Oddometer: 3,030
On further searching, it appears they are the same. It is a very good idea to switch to a handlebar mounted master cylinder. Others with more experience with the nuts and bolts aspect of that will chime in shortly. The huge crack and recent repaint on that tank on ebay speaks of bodywork done poorly, I'd pass on that one. If I were going seriously off the beaten path, I'd carry a few small backpacking fuel containers.
Big Bamboo is offline   Reply With Quote
Old 09-29-2013, 08:35 PM   #14
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,592
The last time a decent /6 tank with an OEM black paint job sold on Ebay was only about a week ago. I lost . That tank went for $670 with a shipping charge of $40.

A decent /6 tank in black is very hard to find. If you will take another color and maybe paint it not so bad.

Why do you think you need more fuel than a standard large tank holds? There are the Luftmeister saddle bag tanks.

Here is an older thread about large tanks.

http://www.advrider.com/forums/showt...php?p=11895482
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 09-30-2013, 06:30 AM   #15
garyinalt
Adventurer
 
garyinalt's Avatar
 
Joined: Aug 2008
Location: Woodstock, GA
Oddometer: 67
The tank with the narrow bottom and stick on emblems might just be a /6 part for the R60/6 which was the only model 1974-1976 with the drum brake up front. So there was no master cylinder to contend with under the tank.
__________________
77 R75/7
78 R100/7
93 R100R
95 MZ Skorpion
garyinalt is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 07:20 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014