Topic: tank swap - fuel feed question

[cbjunkie]

well, i searched for answers first - if anybody can point me in the right direction, thanks!

Project: I've purchased a Super Sport tank and am going to replace my stock K1 tank. the K1 petcock has two fuel nipples and the SS tank only one.

question: any reason i should have a problem with fuel feed/starvation or do i just need to provide a splitter for the tubes?

thanks, all...over and out

[dusterdude]

splitter should work just fine,it will take a little extra time to fill the bowls when they are empty,but once they are full you shouldnt have any problems

[ProTeal55]

I agree with Duster. I don't see putting a " Y " in the single feed being a issue.

I thought you couldn't run SuperSport tanks on the older bikes ? 
Will the factory tank mounts adapt to your new tank , or are you
doing something custom ?

[Dennis]

My 750 SuperSport runs fine with the single outlet petcock that Honda installed on the tank at the factory.
I don't see why your 750 K1 won't run just as well unless you have greatly increased fuel demands due to engine mods you didn't tell us about.

[frostypuck]

The way I see it, when I drain a tank, it takes maybe 15 minutes, tops. I've never had a bike consume a full tank of gas in 15 minutes with ANY hi-po mods. I thought the two nipple system was one for "ON" and one for "RES" because when I take off a petcock, there is one tall pipe inside and the second nipple is fed from the bottom of the tank. Therefore you'd be running on only one fuel line anyway.
And as far as I know, the shape of the tank is what makes the F tanks not go so good on K bikes, they don't match up with the seat very well, but mount the same. I don't think Honda went thru the bother of changing the frames so that only K tanks would fit K bikes, but I could be wrong.
Good luck,
Chris in Boston

[Dennis]

.... when I drain a tank, it takes maybe 15 minutes, tops. I've never had a bike consume a full tank of gas in 15 minutes

I have never drained a tank through the petcock and timed it. I have no reason to doubt what you say. If I want to dran a tank I usually just turn it upside down over a clean 5 gallon plastic bucket - outdoors. Usually only with less than half a tank when done that way.

I thought the two nipple system was one for "ON" and one for "RES" because when I take off a petcock, there is one tall pipe inside and the second nipple is fed from the bottom of the tank. Therefore you'd be running on only one fuel line anyway.

Each of the fuel lines from a dual feed petcock runs to a tee which feeds 2 carbs. One line feeds carbs 1 & 2 and the other feeds 3 & 4. The reserve pickup feeds the same lines from a different source. There is no way for the fuel to cross over to the opposite side carbs.

[cbjunkie]

thanks, lads...the front mounting rubbers are the same, the carbs don't hit the bottom of the new tank and the rear rubber lockdown lines up proper - all i have to worry about is what kind of butt protector i'm gonna lay over the frame...

the "on" vs. "res" explanation makes good sense and unless i hear different from a BTDT i'm gonna go for it.

thanks, all
j'lo...

[Dennis]

........ unless i hear different from a BTDT ........

"BTDT" ?

                  WHAT?

[skamania19]

Believe that's shorthand for a fellow that's "Been There, Done That."

[frostypuck]

I'll admit my mistake. Yup, each line from a two nipple petcock runs to one pair of carbs. The valve inside controls whether fuel is taken up by the tall pipe ("ON") or the no-pipe (RES). But I've Tee'd a single petcock into two, with no adverse effects.
Later,
Chris in Boston

[ProTeal55]

What are you doing with your stock tank ?

[cbjunkie]

 
stock tank - it's definitely a keeper. i'm going to modify, but want to keep my options open at this point...i have no idea what kind of seating mods i'm going to run in to with the SS tank on the bike. it extends a few inches beyond where the stock tank did, so i'm going to end up modifying a K1 seat pan i ass-ume...

right now i'm using a throw pillow off the couch, don't tell my GF where it went!!!

j'lo...

[ProTeal55]

Nice - Post some pics of the bike with the SS tank , if you could.
I think that tank on my bike , would give it a much sleeker appearance...

[cbjunkie]

hmp...resizing these is a real pain...

[cbjunkie]

OKAY...let me know if this works, proteal...

file:///c:/DOCUME~1/RMR/MYDOCU~1/PICASA~1/postable/INDEX~1.HTM

you should be able to cut and paste that into your browser window.

[Geeto67]

what is wrong with putting the k1 petcock on the supersport tank? the thread sizes should be the same. The only real issue I se is that the potential is for the switch to be on the wrong side (IIRC the SS fuelcock is on the left and the K1 is on the right). I forget if the k1 fuelcock is one where you can turn it independantly of the fastening nut (like the later 750 fuel taps), but if it is you should be in business.

[Dennis]

what is wrong with putting the k1 petcock on the supersport tank? the thread sizes should be the same. The only real issue I se is that the potential is for the switch to be on the wrong side (IIRC the SS fuelcock is on the left and the K1 is on the right). I forget if the k1 fuelcock is one where you can turn it independantly of the fastening nut (like the later 750 fuel taps), but if it is you should be in business.

 

Totally different design, cannot be swapped without major mod to tank. There is no nipple welded to the tank in the older designs. Petcock mounts with 2 machine screws (like the phillips used on the engine cases) and seals against the tank bottom with an o-ring.

[cbjunkie]

exactly.

did that photo link work for you guys...it's a new program i'm trying - my pix were to "heavy" to post here...

[cbjunkie]

nah, a pain in the ass...

i'm going to try and get them hosted online somewhere...check your email for an invite.

[ProTeal55]

Got the email invite - thanks 

I like both tanks on your bike , hard decision...
Both tanks look good..
The SS tank is like a slimmer version of the tank on my bike now.
The stock "Peanut" tank is more retro I think.
What year bike is the SS tank from ?

You sure you don't wanna sell me your stock tank ? 
I think you just might want too.....Maybe do a trade for something ? I have lots of
"stock" parts you might want...

What size rear tire you have on that thing ? It looks "thicker" than stock...

[Geeto67]

I didn;t realize the earlier tanks used screws and an o-ring. Until recently the earliest SOHC I had ever owned was a 1974 (now it is 1973). 

Pingle makes a dual outlet petcock for just about any bike (most modern fuel taps are one of a few standard szes). It may be more expensive than a y splitter but you don't have to worry about fuel starvation to the carbs.

[cbjunkie]

tire: 'tis...PO fitted that on there - i like it, but haven't had to figure it out yet - will leave that tire on for the winter just for rolling around the shop

i can't let the tank go quite yet, but i have developed an agressive "tank search strategy" on ebay - if you can give me some particulars as to what you are looking for, i will alert you to any likely candidates.  as other members have pointed out, and they're quite right, the SEAT is going to become an issue when moving to a longer, i.e. SS, tank.

from those pix you can see that the rear mount is "shrouded" by the SS tank itself, whereas on the stock tank the mount protrudes from beneath - however, distance from the front mounts to the rear clip on the stocker is 19 3/8" and on the SS the number is 19 5/8 - plenty of room for the rubber seat to grab onto and hold.

btw, i don't know the year of the SS tank - i will check the old ebay listing to see if it was posted...

hey - if you have that URL for the photos will you please post it here so others can look? thanks...j'lo...

[cbjunkie]

i erased the listing already, sorry - from what i remember the year was not specified...

i knew that i wanted a Super Sport tank and that i wanted one with a lid on it - i'm gonna POR-15 the heck outta it and go my merry way...

[ProTeal55]

See Below :

SS Tank
http://photobucket.com/albums/b207/cbjunkie/tankswap/?action=view&current=rocker1.jpg

Stock Tank
http://photobucket.com/albums/b207/cbjunkie/tankswap/?action=view&current=stocker1.jpg

I def. think I like the stock tank over the SS tank , for what I want to do with my CB. I think it has more of a retro feel, which is kinda
how my bike is turning out , to be a bobber more than a Cafe. If you want to sell that stock tank of yours let me know. I like
it because it is allready black.....

[cbjunkie]

hmmm...why don't  you send me some pix of tank she's wearin' now...

[ProTeal55]

U got's mail