Fuel tank upgrade, putting the "G" in my "L"

[DanTheMan]

This project is being done with the aid of the donor "G" that probably can't be titled that I bought last month. In order to put the larger tank on the "L" frame, the triple tree from the "G" needs to replace the "L" tree.
New "ears" for mounting the tank will be welded to the frame, the original ears removed so the tank is a far forward on the frame as possible. I'm upgrading from the 3.2 gal stock tank to later model 4.5 gal "mystery" tank that I bought from JWhelan. The worst part of the project so far has been obtaining the lower steering stem bearing, required a 120 mile round trip yesterday in my diesel guzzliing pickup since I had the bike in pieces. I'll have the project done today, with more pictures.
Anyway, here are the pictures, starting with the donor bike prior to dissection.

In process:

One of my supervisors....

Both bikes in a state of disassembly..

More to come in the next post....:-\\\

 

[DanTheMan]

As promised, more pictures, oh depending on how I like or dislike the handling with the "L" forks kicked out an extra 1-2" with the "G" triple, I'll probably rebuild the "G" forks to see which handling characteristics I like best. I don't have the time to do that right now (gotta be done by tonight), so I'm going with my newly rebuilt "L" forks.

Here's the new tank mocked up on the frame, last picture until I get the mounting done.

More later today.

 

[Steve]

Which G model only had a 4.3 gallon tank? :-k

My wife's '82 850L has a 4.5 gallon tank, the two 850Gs ('80 and '81) both have 5.8 gallon tanks.

.

 

[DanTheMan]

Which G model only had a 4.3 gallon tank? :-k

My wife's '82 850L has a 4.5 gallon tank, the two 850Gs ('80 and '81) both have 5.8 gallon tanks.

.

The tank I'm installing appears to be a later model "?" 4.5 gal (yep that's what I wrote) I THINK. I bought it from JWhelan. The tank off of the "G" is way too big at 5.8 gallons. In order to fit the tank I'm installing on my 1980 850 L I had to change a few things (hence parts from the "G") or else the triple tree upper would hit the tank (unless of course I moved it further back on the frame which I didn't really want to do).
Maybe this clears up some confusion, I didn't mean to say I was installing a "G" tank, my bad.

 

[tkent02]

Have you looked into titling the far superior G bike?
You could ride it with the L's plate until the title is straightened out.
International Title Service, or going through someone on this forum in a non title state are options.
There are others.

 

[DanTheMan]

Have you looked into titling the far superior G bike?
You could ride it with the L's plate until the title is straightened out.
International Title Service, or going through someone on this forum in a non title state are options.
There are others.

I might do that later. At the moment, I'm not even it sure it runs. The starter is toasted (the engine isn't seized, turns by hand easily), several other problems, had new plugs, some old gas in the tank, someone tried to make it work and couldn't at some point in time. It has 67k original miles, but sorely neglected. The steering stem bearings were pure rust. Right now, the L runs good, I've rebuilt the carbs on it and done the valve shims, and it's been my daily driver since '05. The G will probably turn into a winter project. Oh, the tires on the "G" are old Dunlop Elite II's from sometime in the '80s or '90s.
I wouldn't dare ride it with the L plates, especially since I'm planning a cross country trip in the near future. All I'd need to do is get pulled over in CO (where my license was suspended in '76, never redeemed), have them check VIN against plates, and off to the slammer I'd go. Nope, it'll be legal 100% before I'll ride it.

 

[DanTheMan]

Here's the completed project picture. I worked on it until the wee hours of the morning on Friday, then went to bed, took a short test ride, loaded it on the trailer, and headed for Jay Cooke State Park for Memorial Day weekend, since I was teaching the BRC in Duluth Friday night, Saturday and Sunday.
Problems encountered: Gas gauge sending unit is on the opposite side, I have to pull the sending unit and flip it over for the gauge to read right, or buy the one made for the tank. A small piece of something got into my float valve on #2 carb, stuck it open until I rapped on it with a screwdriver. I like the new tank much better, after I paint the badges where they look good, I'll put them on. My son said it looks better without them, I'm not sure yet.
Here's the picture, the bike really needs a bath....

 

[DanTheMan]

OK, the tank is not an "L" tank of any year. I still haven't identified what it's from, I was looking on PartsShark for a fiche with this tank and I haven't found one yet. I thought I would be able to source the tank float/sending unit mounted on the right side. I'm in the process of flipping the coil over to get the gauge to read right, but I'd like to source a new gauge float and sending unit. If anybody else has a gauge sending unit mounted in the right side of their tank, let me know what it is.
Thanks!

 

[salty_monk]

Your pics are a bit small but it looks like an 80 550 tank to me....

 

[DanTheMan]

Thanks Dan. I'll have to check that out. I've got a working gas gauge now. It's also nice to have that extra 1.3 gallons to ride on, it is a 4.5 gal tank. Reserve happens at 2 gallons because I'm using the petcock off of the 5.8 gal tank that came on the G.

 

[salty_monk]

Z1 do a low reserve petcock that might suit... Did you get a petcock with the tank? 80 550 had the one with the prime that needed a screwdriver to open.

 

[drtybykr]

If anybody else has a gauge sending unit mounted in the right side of their tank, let me know what it is.
Thanks!

My L's sending unit is mounted on the right of the tank

 

[DanTheMan]

Z1 do a low reserve petcock that might suit... Did you get a petcock with the tank? 80 550 had the one with the prime that needed a screwdriver to open.

No, when I got it, I got a bare tank, no cap, sending unit or petcock. The G one will work for me for now. The screwdriver operated one off of my L tank had the wrong bolt spacing to use on this tank.

 

[DanTheMan]

My L's sending unit is mounted on the right of the tank

What year is your L? I was looking at newer models and they all had the sending unit on the left side like mine.

 

[drtybykr]

What year is your L? I was looking at newer models and they all had the sending unit on the left side like mine.

Mine is an '82

 

[salty_monk]

Have a serviceable 750 (83) petcock if any good for you...

 

[sschering]

So if I understand this you are running L leading axle forks in G (non leading axle) trees?

 

[salty_monk]

Yes.. that's what he said. Increases rake a little bit I think....

 

[Skateguy50]

Now I am all for more gas in the tank, but Steve said his wife has an 850 L with 4.5 gal... so couldnt you just find that tank to swap? I know for me with the 650L it would involve a big process like you did. I think my easiest swap will of course just be an upgrade in the bike, eventually.

 

[sschering]

Yes.. that's what he said. Increases rake a little bit I think....

No.. The rake on L and E,G trees is identical...
I've had both on my 79 L and measured it.
the big difference is the offset in the trees..
L trees have 3/4" less offset than E/G trees. (distance from the stem to stanchion CL)

This is to compensate for the leading axle adding about 3/4" offset.

They did all this to keep the trail consistent between L and E/G forks..
Near as I could measure Trail and rake were identical between L and E fork sets..

By mixing L forks with E/G trees you are shortening trail by almost an inch making it close to the trail on a GSXR.. Something like 3.8 inches if I remember.

Top clamps..
Top is a L
bottom is a E
Note the difference in offset.

Anyway.. If you figure out what the new tank is from I'd love to know.. the tank on my L is in sad shape..