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I'll throw my 2 cents worth in. You might want to put the stock air box back on and test. I put a freer flowing intake on a Mukuni 40mm rack and they ran like you are describing. I played with jetting and settings for a couple weeks with no luck. Back to factory settings and stock air box and it was fixed. I am not a carb guy but the only explanation I can see is the freer flowing air box does not build a big enough pressure differential across the carb to draw fuel through the circuits or lift the slides quickly enough.
 

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Discussion Starter · #203 ·
gave up on the CV and installed a Keihin CR31 carb rack. tuning is easier to be sure. Now my question is; has anyone here tuned using an O2 sensor? any issues with welding bungs into the exhaust? i know i need to do this for all 4 cylinders, just hesitant to take the exhaust apart to weld in the bungs. anyone have any recommendations on products/kits to do this?
 

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I've done it on a dyno using a single probe in the collector.
Between. That and checking the plugs, you'll get where you need to be.

I don't think its necessary to check each cylinder separately unless you're really pushing the limits.

You can also weld in a bung at the collector and get an O2 sensor kit with a AFR gauge. You don't have to run it all the time, but it can be invaluable for checking changes you've made.
 

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You had issues with your cb900 carbs not long ago now that I think of it.... you should be a CV expert by now.

But I have used innovate motorsports data loggers and wideband o2 sensors. You need wideband because narrowband ones are only accurate at stiochiometric ratio.

Honestly, carb tuning is not hard... as long as you know the engine and carbs are mechanically sound. That's the biggest hurdle. All the tuning aids in the world won't help a bad engine run right. Using an o2 sensor is kinda overkill but can help people that are not so confident.
 

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.... Now my question is; has anyone here tuned using an O2 sensor? any issues with welding bungs into the exhaust? ...
You just described an ordinary modern day motorcycle exhaust manifold. Anything with a catalytic converter is going to have an O2 sensor.
 

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Discussion Starter · #207 ·
thanks for the input on this CR Carb. i think it's dialed in for now. Question i have, with the CR Carbs, the petcock bumps into the top of the #1 Carb and doesn't allow the tank to sit down correctly. if you've had this same issue, how did you handle it?
 

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I got my aluminum tank from Evan Wilcox. Same basic price and you don't have to deal with shipping it half way around the world. I met him when he was making the bodywork for the prototype Victories and considered buying a bike just to have something I could put his stuff on. A bunch of years later I pulled the trigger for some Ducati bodywork.



 

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I'd love to have him make some stuff. A true master at shaping metal.
 

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Discussion Starter · #212 ·
I got my aluminum tank from Evan Wilcox. Same basic price and you don't have to deal with shipping it half way around the world. I met him when he was making the bodywork for the prototype Victories and considered buying a bike just to have something I could put his stuff on. A bunch of years later I pulled the trigger for some Ducati bodywork.

this is absolutely gorgeous.

 

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Discussion Starter · #213 ·
alright my friends, new problem. because my CR carbs are a little taller than the CV, my petcock will not work. tried 3 different sizes and carbs always get in the way. So, options are cut the original bung off and have a female bung put on, which i don't want to do really. Or, install an inline petcock. i'm going with the latter option, but i cannot find a 16mm female inlet to 5/16" hose outlet. so, looking for any ideas how to put a simple connection to the tank that will feed gas to the inline petcock.

thanks.
 

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You need to find out what the thread is on the tank side.
Usually petrol threads are bsp but im not sure on these hondas.

If its just a normal metric thread it may be a little more difficult
 

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Discussion Starter · #217 ·
f
Or this... you would have to change the o-ring to a nitrile one as this seems to be for a beer keg haha


I found these by googling "m16 barb fitting"
Have a look theres plenty of results to look through
so much for searching M16 female to barb adapters, haha. thanks for this.
 

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Discussion Starter · #218 ·
Dorman Products offers a M16 Female to 5/16" barb for fuel lines. not a 90 degree, but works well enough
 
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