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I recently replaced the exhaust tips on my 1974 Honda CB 360G-The air and fuel mixture is off and I would like the remedy other than buying a $100 +$$$ tool- If anyone could enlighten me on a step by step process that would help out, Please. I'd like to be riding my racer some time soon. Thank you
 

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anyone who is going to give you a useful asnwer, and it isn't likely to be me, is going to need more info. so you put new pipes on, what exactly is the symptom? is it rich, or lean, did it run well before you put the new tips on? if it didn't you might be better off starting from stock and tuning it from there so you have an idea of how it oughta run. did you clean the shit out of your carbs? do your air mixture screws do what they should? what is this $1000000 tool you speak of? welcome to the world of vintage honda's

...connoisseur of slack...
 

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most clymer manuals have plans for making a honda carb synching tool in the back out of clear fuel line and baby food jars. however just changing your exhaust is not going to cause your carbs to go out of sync. what is your intake like? stock or pods?
 

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I don't mean to hijack the thread, but where do you get clear fuel lines? The only thing I found was clear PVC hose that I heard isn't good to use for fuel lines. Supposedly the fuel will slowly eat the lines. Did I hear wrong or am I looking at the wrong stuff?

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I used to order clear fuel line from parts n more but you can get it at any motorcycle dealer with a parts unlimited catalog.

for making a sync tool you don't need fuel proof as you will be using water.
 

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A " ball park" way to syncronize carbs on the twin is to feel the exhaust pressure coming out of each pipe. They should feel "ball park equal". It wont be as accurate as the Mercury/ water sync tool, but will work in a jam. Adjust your idle mixture screws to be equal and resync as needed.
The "ball park" syncing will work if the exhaust is not siamesed (come together to 1 pipe) or connected together under the bike (or connected like the CL exhaust at the muffler).
DG
 

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quote:
I don't mean to hijack the thread, but where do you get clear fuel lines?
big box home improvement stores nearly always carry 1/4" silicone tubing in the plumbing section.

NCNR
 

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oreilly's carries clear fuel line! Ok huge newbie ? what is synching carbs? wow I hate asking that obvious question. cause now it's obvious I'm an idiot! but i thought I knew a lot about carbs but I clearly missed that?
 

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1.5 turns out. go from there. synching them is making sure they are pulling up the same on both sides. if you have cv carbs. there really isnt anything else to do. the only thing you should have to do is maybe jet up. but if you didnt change filters, most carbs dont need it. if it does, itll fall on its face at wot. pulling on the choke at wot should clean it up a little. if it does, jet up.

synching other carbs means checking if the vacuum is the same using a manometer. you use a gauge that goes between the carb and the intake valve. usually a bung on the carb is removed, then the hoses attached. the guage will read the vacuum and let you know which carbs are pulling more and which are pulling less. adjusting he cables or linkage is how you change those numbers. with cv carbs, the vacuum slide does this automatically. the reason there is no adjustable needle on a cv carb. so the only thing you can do is make sure the butterflies are opening simultaniously, by adjusting the cables and idle speed screw. the butterfly opens and allows more vacuum on the idle circuit bringing in fuel. as the slide detects more vacuum, it lifts bring in more gas through the needle jet. so if youre running stock carbs, make sure the idle adjusts are the same, the cables pull the same, and the air screw is out 1.5 turns to start. keep in mind, a carb that is clean and actually working, will be affected alot by any changes made. a dirty shitty running carb will be affected alot less by things like jetting changes etc. basically, you can jet and airfilter til you puke, and make little or no difference on a screwed up carb.

jc






Edited by - joe c on Oct 08 2007 9:13:03 PM
 

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cool so if I put pod filters on stock 360 carbs I'm prolly gonna need to jet up? where can I find jets? sorry didn't mean to take your topic
 

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David: it's tuning you're after, not syncing (though that is a sort of integral part of the tuning process). First make sure your carbs are internally spotless - most of the time, esp. with rich mixture, the problem is a clogged passage rather than an incorrect jet or even badly set mixture screw.

Listen to Joe C - dirty carbs are totally unresponsive to tuning.

Sam - it's actually unusual for a vintage Honda to need to jet up after installing pods. It's technically very plausible, but in practice, esp. for the city rider, the stock jets are a little on the rich side so it's rarely necessary.

a
 

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believe it or not, pods dont flow that much more air. neither do k&n's. if youve bought a pipe for street use, then theres a good chance jetting isnt going to be required. obviously it depends on alot of variables. im not saying its never going to be required, just that they tend to build street pipes for people who dont know. a pipe and filter setup is more likely, obviously, to need a needle adjust or jetting change. now, for example my full on race pipe i put on the cb550 only required adjusting the needle. but im running a stock airbox. it still lacks a little mid range perfomance, but im attributing that yo the pipe. the bbr pipe for the xr100 came with the proper jets (hey, now theres an idea!!). but that was a huge difference in pipe design. stepped header etc....you really have to figure it out yourself. and see where it breathes differently in the rev range. you can order jets from any honda dealer....or whatever.

jc
 

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thanks guysI will get her out in a month or so and see how she runs.. I gotta get my battery fixed first..
 

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Thanks for the tips on the clear fuel lines. I was at sears and all they had was clear pvc and regular black fuel line. Not a big deal right now, I have way more important things to do on my bike. I was just wondering for future reference.

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any local motorcycle shop will have clear line. i use the clear blue stuff from parts unlimited.

jc
 
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