DO YOU NEED TO REJET THAT CARBURETOR????

G

getindachoppa

Been Around the Block
I have heard this question MANY times and I will give you some of my personal experience with this and maybe it will help you out. Okay this is my experience with carb rejetting on motorcycles and well any machine that has a carburetor. Anytime you modify the originally factory setup up exhaust and intake specifications your going to have to do SOMETHING to the amount of air and fuel that goes into the engine. NOW with motorcycles my experience is that when the exhaust is changed you might need to change the air fuel ratio some, BUT when you change the intake for example with pod filters or whatever it changes the air and fuel ratio GREATLY! For example I am currently building a CX 500 cafe racer right now and I am keeping the air box on it. You can put pod filters and less restricted exhaust on the CX 500 and rejet the carbs and you WILL gain some performance out of it. You have to know what your doing! The worst thing you could do is make a lean condition where you start burning up things in the engine. Pod and velocity stack type filters two into one exhaust and straight pipes are really more for bike racing applications. The Honda engineers setup the CX 500 with an airbox and exhaust that will give your ROAD machine the BEST performance and the BEST economy out of your bike. Now notice what I said here ROAD machine. I am not going to be racing my CX 500 and will just be cruising the roads with it so all the modifications are not necessary. NOW with that being said a lot of shops that build bikes put POD filters on or change the intake some how to clean the bike up and give the bike that race look that everyone likes. But like I said before you have to know what your doing and if you start messing with the factory specifications a lot of novice people end up with a performance turd that was worse off than before. Now they are complaining because their fancy exhaust and PODS just cost them an arm and a leg and didn't do anything for them. If you are still bent on that fancy exhaust and racing intake for your bike than do your homework FIRST or I recommend taking it to a professional mechanic.
 
I wanted to mention one more thing that might help out a lot of you with this carb rejet question. It could not even be a rejet problem in the first place! Check if the carb is clean than check ignition, compression, intake and exhaust leaks first!
 
Holy shit, there is no way I'm going to read that wall of text, homeboy. I already have a headache, I don't need a migraine.
 
Your headache will be MUCH worse if you don't modify your bike properly. It might be worth it to read it but if you already know how to do this stuff than there is no reason for you to read my post.
 
WOW

I should just give up

I'm going put new bushings in my sk8 board.

Oh wait i might have to change the cups.

Forget it I'm going to drink beer.

Opps cant do that i might need a bottle opener.

Screw it I'm going to be a TROLL on DTT.


PS--YOU DON'T HAVE TO DO ANY THING
 
mlinder said:
Holy shit, there is no way I'm going to read that wall of text, homeboy.
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I think what mlinder is trying to say, is try to compose your thoughts into cogent paragraphs of related sentences. It makes information a whole lot easier to digest rather than one giant block of text.
 
AlphaDogChoppers said:
I think what mlinder is trying to say, is try to compose your thoughts into cogent paragraphs of related sentences. It makes information a whole lot easier to digest rather than one giant block of text.
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I got you.. Im just a bike mechanic not an English Professor.
 
You don't have to be an "English professor" to follow basic writing methods. It would assure that more people will actually read what you write. Just take a few minutes before posting to proofread your post, and make sure your thoughts are grouped in a cogent way.

Regarding your CX500 jetting, I have found that removing the flame arrestor screen, and the intake snorkel along with installing a K&N filter, is a great first move before jetting. It lets in a LOT more air.

Start with around a 130 intermediate main jet, and about 100 main jet. I didn't get all the way through sorting out the jetting on the CX500 that I just built, because I went with a Murray Carbs kit. HOLY MAC SHIT, it made the bike fast, and pulls hard from 2,500 RPM to well past redline. So far, had the bike up to 110 mph and it was still pulling. How do I know it was 110? GPS on board. The stock speedometer was pegged at 85.

See there how I broke that up into paragraphs? Makes it easier to follow. It's OK to start with a stream-of-consciousness block of text if that's what it takes to get your thoughts onto the screen. Then go back and massage the message, and people will read it. I tend to think in paragraphs, and when I have a thought that doesn't fit into the paragraph I am in, I cut and paste it into the paragraph where it belongs. That's just my process. I am not an English professor either, but I did manage to pay attention in fifth grade when they were teaching this shit. I grew up in a trailer in West Virginia, so my basic writing ability wasn't because I grew up in some hoityfuckintoity high class neighborhood. I grew up squeezing milk from the teats of goats and gathering eggs from the chickens and ducks.
 
AlphaDogChoppers said:
You don't have to be an "English professor" to follow basic writing methods. It would assure that more people will actually read what you write. Just take a few minutes before posting to proofread your post, and make sure your thoughts are grouped in a cogent way.

Regarding your CX500 jetting, I have found that removing the flame arrestor screen, and the intake snorkel along with installing a K&N filter, is a great first move before jetting. It lets in a LOT more air.

Start with around a 130 intermediate main jet, and about 100 main jet. I didn't get all the way through sorting out the jetting on the CX500 that I just built, because I went with a Murray Carbs kit. HOLY MAC SHIT, it made the bike fast, and pulls hard from 2,500 RPM to well past redline. So far, had the bike up to 110 mph and it was still pulling. How do I know it was 110? GPS on board. The stock speedometer was pegged at 85.

See there how I broke that up into paragraphs? Makes it easier to follow. It's OK to start with a stream-of-consciousness block of text if that's what it takes to get your thoughts onto the screen. Then go back and massage the message, and people will read it. I tend to think in paragraphs, and when I have a thought that doesn't fit into the paragraph I am in, I cut and paste it into the paragraph where it belongs. That's just my process. I am not an English professor either, but I did manage to pay attention in fifth grade when they were teaching this shit. I grew up in a trailer in West Virginia, so my basic writing ability wasn't because I grew up in some hoityfuckintoity high class neighborhood. I grew up squeezing milk from the teats of goats and gathering eggs from the chickens and ducks.
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Dont know about all that stuff and dont need an English lesson... Anybody here have a carb question hit me up... Im not here for English class.
 
Ok I l live at 5280 ft asl what is the proper jetting for a cb200 with ported heads hot cam bored .75 over and 1mm decked head?
 
Dragon Soaring said:
Oh and 22mm minkuni with 7" velocity stacks
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How does it ride down the road? Is it doing anything? Making any unusual sounds? I need more info on specific problems the bike is making. Thanks!
 
I don't know but I am building it.
Btw 7" stacks would not work well no matter how you jetted it. I found that out by reading a lot of posts by some very knowable people here with experience dating to before you were born.

How can ucome on this site like a wild man and expect any one to listen to you?
 
Dragon Soaring said:
I don't know but I am building it.
Btw 7" stacks would not work well no matter how you jetted it. I found that out by reading a lot of posts by some very knowable people here with experience dating to before you were born.

How can ucome on this site like a wild man and expect any one to listen to you?
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Cant help you till the bike is running... Finish building it, get it in the ball park with the jetting, and run it down the road to see where the jetting needs to be at.
 
OK so I get that this whole thread is a giant piss take (apart from ADC's response) but what is the point?
 
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