Topic: removing fuel tank & carbs on 350F Four?

[Suke]

Hello,
I posted a few questions a week or so ago and got a lot of helpful information from everyone. Thank you VERY much! My bike was/is leaking fuel from the drain hoses when I turn it on, and then it'll just die pretty quickly. It was suggested I drain the bowls and check for debris, get an inline fuel filter, clean my tank and check my floats for anything stuck in there as well as the height. When I drain the bowls, little black stuff comes out that kind of looks like ground coffee. Well, I just installed the inline fuel filter, cleaned the petcock filter and bought the POR-15 tank cleaner kit. I also drained my bowls several times and realized the only carbs that are now leaking fuel are the middle two. I tried starting the bike again after cleaning the petcock filter and installing the inline filter, and it's still leaking although the engine seems to have started a bit better this time. It looks like I need to get to the #2 & #3 carbs, but I'm unsure how to do this since it's really hard to reach them on the bike. I have the Clymer manual, but this is not written for a total beginner like myself.

My questions are- to get to the middle carbs and check the floats, do I need to get them off the bike? If so, the manual says I need to take my fuel tank off first and I've never done this before (although I'll need to anyway to use the POR-15 kit). The Clymer manual says the #2 step of removing the fuel tank is:
"Disconnect one end of balance tube between left and right halves of tank" Uhh, is this written in English?! Could you please tell me what a "balance tube" is and how I disconnect one end? 

Thank you very much! I think I'll be able to follow the rest of the steps and get the carbs and tank off. I hope so because I really want to ride my bike instead of just working on it! I really appreciate your help.

[Sam Green Racing]

Suke,

If you look under your tank you will see the balance pipe.

Your tank is like a saddle draped over the top frame tube/s.

The balance pipe conects the lowest parts of the tank to keep the fuel the same height in both sides of your tank.

If you did'nt have one you might run out of petrol but still have half of a tank full that can't get to the tap.

Have fun,

Sam.

[Uncle Ernie]

Well, after you find it, get a long funnel and a pail. Just pry the hose off with a srewdriver pushing on the end and hold it in the funnel to drain. If there's much gas in there, bring a stool to sit on, and cancel your other appointments. Don't turn on any petcocks until the funnel is underneath the hose and tank outlet. I know you're not stupid, but sometimes everyone needs a reminder.

[Suke]

Great, thanks for explaining what the balance tube is. Is there a standard way of discconecting this bar? I'm still confused on how to get the off. Thanks!

[Sam Green Racing]

It's just a rubber tube that pushes onto two small metal tubes sticking out of each side of tank.
They just pull off, but may have wire spring clips.
Drain fuel from petrol tap first then just pull the balance pipe off the stubs.

[Suke]

perfect, thank you! 

[Suke]

Okay, I like to believe I am a fairly intelligent person however this motorcycle is making me feel like a total idiot! I just spent well over 30 minutes looking for the balance tube but can not find it! Could someone please tell me exactly where I should be looking under my bike? (front, back, behind the petcock, etc.)  I am assuming I should be able to see it with everything attached to the bike, and I am just laying under it looking up at the tank.  Also, I am thinking the tube will go across the width of the tank, but I've looked everywhere and can't find it. I have a '73 CB 350F Four. It'd be really helpful  to know where on the underside of the tank I should be looking. It'd be great to know that other newbies had a hard time with this too...but I think I might be alone in this. Thanks!

[Dennis]

Suke, I don't have a 350, but my 500's and 750 do not have balance tubes. I DO NOT KNOW if your 350 has a balance tube.
I do own one bike with a balance tube. It is a Yamaha RD350. It is quite obvious that it is there. Just drain your tank and when you attempt to lift it (the tank) off the frame the balance (or crossover as it is sometimes called) tube will be looped beneath the top frame rail. Remove as previously described and continue to your carb work.
Just a little side note on this. I have seen where a previous owner has looped a crossover tube above the frame rail (on a Yamaha) instead of beneath. It would certainly be difficult to identify by someone who has never seen one previously, if it was routed this way.

[Suke]

Dennis, thank you very much for your explanation! I'm going to work on this some more tomorrow and attempt to get the tank off and continue with my "project". Thanks a lot!

[kghost]

Uh, I guess I should have read this earlier.

My 350 doesn't have a balance tube. Doesn't need one based on tank shape.

Turn petcock off. Remove fuel hose from petcock. Remove rubber from tank end under seat. Pull tank back and up.

[Dennis]

Hmmm.............
...... does this mean that Clymer got it wrong? Again?

Well Suke, if it's there or if it's not, you know what you have to do!!

[Druro]

It just so happens that i have a 350f that i'm working on, and neither of my tanks has a balance tube.  Perhaps the manual is wrong (believe me, it happens more often then you'd believe.)

[Suke]

Hi all,
Well, you guys were right and Clymer was wrong! I was easily able to take off the fuel tank based on your input, whereas the Clymer manual instructed em to take off the balance tube. Too bad my bike doesn't have one. I am now going to clean my tank with that POR-15 kit and that'll hopefully get rid of any sediment in my tank.

I also installed an inline filter as was suggested.

The last time I started my bike, the two middle carbs were still leaking fuel out of the drain tubes. I drained the bowls, but I think I need to open the bowls and see if the pin is stuck. I bought some carb cleaner I want to spray around in there too. I am a complete rookie with bikes and especially the mechanical work involved, so I am confused on how to get the middle two carb bowls off. I tried a stubby screwdriver but I can't reach far enough in to unscrew while still attached. Do I need to take the carbs off the bike to get to the middle two carb bowls? My Clymer manual says to "disconnect the throttle cables at the link lever, and then loosen the air cleaner connecting insulator bands." Is this what I need to do to get to those bowls? If so, can someone please explain where the throttle cable at the link lever is, and how I disconnect it? Sorry for al the questions, but I'm trying to learn the best I can and this is the best resource I've found.

Thanks again!   

[gaijin]

I'm in the midst of doing the same things on my 400f and have similar questions... (I'm even cleaning my tank with POR-15  )
I watch eagerly for responses! Thanks to Suke for asking questions and everyone else for answering.

[pmpski_1]

I tried a stubby screwdriver but I can't reach far enough in to unscrew while still attached.   

I'm not sure exactly what you mean by "unscrew while still attached", but this tool has been really good to me. Just make sure that you use the correct sized tips or you'll strip the heads.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92630

[Suke]

Gaijin- good luck with your project! Hopefully you are not feeling as confused as I am.

Pmpski- Thanks for the info on that tool. I actually just bought one of those (or something similar) at a local store. As for my original question, I was asking if you need to take the carbs off the bike to get to the middle two carb bowls. Even with this tool, it's extrememly difficult while they are still attached to the bike, but I don't really understand how to get the carbs off the bike. All I want to do is get the middle two bowls off and see if anything is stuck in there, and clean them out a bit. What is the best way to reach them?

Thanks again!

[Salem350F]

Probably the easiest thiing to do in the long run is to take the rack of carbs off the bike, it isn't that hard.  If you do manage to get the two center bowls off to examine them just remember how hard it is to get them off- it will be even harder to get them back on.  I've done it on my bike, it wasn't fun. I eventually had to rebuild the carbs anyway.  Just my two cents worth.

[Suke]

Thanks Salem! I'm just not sure how to do this?  My Clymer manual says to "disconnect the throttle cables at the link lever, and then loosen the air cleaner connecting insulator bands." Is this how you get the rack off? Are you able to explain or let me know how I can find out what and where the throttle cables at the link lever are, as well as the insulator bands (I am assuming these are those black rings near the air filter).

Thanks!

[keiths]

The throttle cables should be obvious once you get the tank off. Just turn the throttle and watch the cables push and pull the throttle shaft. There are hose type silver clamps on both the air side and the engine side of each carb. Loosen each one and slide them away from the carbs. There is another band between the air manifold and the air box. You need a long shaft Philips screwdriver to loosen it. You can see it from the fuse side under the side cover near the frame. The rubber pieces have become very hard after several years, so now its much harder than it was when new. Try a hair blower it soften things a bit. Check the old posts for more hints. I push the carbs forward and down in the back.
Good luck!

[Salem350F]

Previous post has it right about the removall. Loosen the adjustment nuts on the throttle cable holder to get some free play.  after you loosen the clamps everything will be tight! Hair dryer will help. When you are reinstalling a little silicon lube goes a long way to sliding them back on.  Remember to disconnect the drain hoses.  When you have the carbs off is a good time to examine your fuel feed  hose, if it is at all questionable, now is the time to change it because you can only do it with the carbs off.  Good luck, any question just ask and I will try to get back to you or email me at jbellanca@verizon.net  I check that all the time.

[Suke]

Thank you very much for the detailed answers! I'll give that a shot and hopefully it'll work. Thanks again!