CNS Jets

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Hoze513

Hoze513

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Iam finally going to gets a couple of Jets for my CNS V2 carb. But I still don't know the jet size that comes with this carb. Does anybody know? I try looking aleady, but I come up with two numbers (70, 72 ) 6mm. I do not want to get drill bits. Iam going to just order them from pirate cycles, since Iam going to order a MM intake too next week. I have a PK80 (68.8cc), SBP muffler. Also how much bigger size jet did you have to go up to? What Jets size do you recommend for me? Thanks Jose
 
Greg58

Greg58

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You will have to tune the carb for your engine, a lot of thing affect engine performance. The elevation where you live makes a difference also. The jet on my cns is the largest of the friends I ride with that run the cns, but I have done porting on mine. I bought the drill bit set and drilled mine one size larger at a time till I got it right for my bike.
 
Hoze513

Hoze513

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Nov 24, 2011
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Joliet, illinois
Greg58 said:
You will have to tune the carb for your engine, a lot of thing affect engine performance. The elevation where you live makes a difference also. The jet on my cns is the largest of the friends I ride with that run the cns, but I have done porting on mine. I bought the drill bit set and drilled mine one size larger at a time till I got it right for my bike.
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I did porting on my too. Next week when I order the jets Iam going to get a MM intake too. How many times bigger do you thing you went? I went on SBP web site, and it said stock jet for the CNS is 0.72mm. And I have seen on other places it is 0.70mm.
 
Greg58

Greg58

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This is not a recommendation but my jet is at a #64 drill or.036 in or. 9144mm. Like I said do not start with that size, you need to go by the spark plug color to get it tuned. The micro drill bit set is only $7.75 shipped from amazon, it has #60-#80 bits and a hand drill. That was the easiest way for me, I drilled mine two sizes bigger to start then one size at a time till I got it right. It took awhile but I did a plug chop with ever size change.
 
Hoze513

Hoze513

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Nov 24, 2011
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Joliet, illinois
Greg58 said:
This is not a recommendation but my jet is at a #64 drill or.036 in or. 9144mm. Like I said do not start with that size, you need to go by the spark plug color to get it tuned. The micro drill bit set is only $7.75 shipped from amazon, it has #60-#80 bits and a hand drill. That was the easiest way for me, I drilled mine two sizes bigger to start then one size at a time till I got it right. It took awhile but I did a plug chop with ever size change.
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Wow that is big. I do have another jet that someone gave me. It is almost twice the size, but doesn't have a number. That one was way too big. The bike had no kind of speed, and it also was bloging. The one it's got now, it will blog in the beginning. But then I let go of the throttle, slowly hit the throttle again, and then it will pick up to speed. More smoother after that. Thanks Jose
 
Hoze513

Hoze513

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I have decided not to buy CNS jets. It willl be much easier to buy drill bits. I just don't know where to get at. Do hardware stores carry them. Much easier than ordering them. Thanks
 
Greg58

Greg58

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Jose, it sounds like from what you said about the sound of your engine you are fairly close. A little four stroking till it reaches operating temperature is what mine does, as has been said on this forum many times you have to tune most of these carbs to your engine. Like I said before three of us that run the same engine all run different jet sizes, all have correct spark plug color. So don't just drill your jet because of what you read drill it because of need.
 
Hoze513

Hoze513

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I went to the Hardware store, and they did not have the bits I was looking for. Does anybody have a link to where I can get those kind of bits. Thanks
 
Hoze513

Hoze513

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I went on Amazon. com, and made an account. But I didn't write my address right. No matter how many times I try to edit my address, it will still go back to my 1st address. So after 30 minutes of trying to fix it, I just left it along.
I decided to go to a local hobby store and got them there. $25.oo for these cheap bit with no hand drill. Well I got them there, just so I can get started on my bit this weeken. :-||
 
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nightcruiser

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I got my set on Ebay for about $6 bucks, it came with a hand drill and all. I do use Amazon.com also, but I kinda prefer ebay cause Amazon don't take PayPal... Local stores can tend to soak you at times, which is unfortunate, cause I would prefer to shop locally as well...
At any rate, happy jetting!

PS Do your float adjustment before you jet, it can effect the mix a lot.
 
Hoze513

Hoze513

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Talk about being a dummy sometimes. I decided to check my plug the right way. It is chocolate brown. No need for the bit. Just a waste of money. All I need to do is tune the carb now. And a few other things to my bike.
 
Greg58

Greg58

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Jose, may sure the choke plunger is seating all the way since it adds fuel to the mixture when open. If your cns is running rich it will be the first I have heard of with a stock jet, most are lean.
 
Hoze513

Hoze513

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Nov 24, 2011
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Joliet, illinois
Greg58 said:
Jose, may sure the choke plunger is seating all the way since it adds fuel to the mixture when open. If your cns is running rich it will be the first I have heard of with a stock jet, most are lean.
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I made sure the choke was off. I was really surprise too. I have a SBP muffler ( with out the silencer), port and polish intake, PK80. About 1/32 mix Lucas semi synthetic. This is what I did before I check the plug. I rode my bike at full throttle. Then I put the clutch in, let it ride down hill for a little bit. Turn off engine, then cool off. Check plug. Did I do that right? I think my floats are kinda low too. Thanks Jose
 
Greg58

Greg58

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May 1, 2011
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I have a friend that had the same problem, he had the choke cable adjusted to tight. Since the choke plunger has a spring holding it down you can loosen the cable at the lever and remove all doubt. If you do a plug chop with a new plug you get a better read, run at full throttle for a fair distance and hit the kill switch and let off the gas and pull in the clutch at the same time. Pedal back home or stop and let the engine cool and check the color of the porcelain not the electrode. A low float will not cause a rich condition.
 
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