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Discussion Starter · #1 ·
Ok so I just got the 44MM big bore piston and cylinder from davesmotors.com I put it on everthing worked fine then it starts to bog down so I took it to my shop started it again gave it a little gas it was like everthing was fine but when I gave it more gas it bogged down real bad and almost shut off.

The only mods I have are the UFO air filter and diffrent fuel lines.
 

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Your mixture is way too lean. Don't keep running it until you richen it up or you will melt the little piston right out of it! Bigger bore needs more fuel!

The best way would be to rejet with a jet kit, but, you could try adjusting the c-clip on the needle first. Most of the carbs come with the clip in the center position; try moving the clip down one or two notches and see if that helps. If it is still too lean, then replacing the main jet is your only option.
 

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Discussion Starter · #3 ·
Were is the C clip located?
 

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I know this is where most people will say "use the search button", but, I hate it when people do that.

The c-clip and the needle are inside of the carb. Follow the throttle cable to where it inters the carb. You will notice that there is a cap, on the carb, that is threaded. Remove this cap with the cable attached. In side of the carb is the venturi slide and the needle is poking out the bottom. Carefully remove the throttle cable from the slide and the needle will fall out. The needle's position is held by a very tiny c-clip in one of 5 grooves in the needle. Very carefully remove the c-clip and move it down a notch or two to richen the mixture. Reassemble everything and give it a try.

Be careful putting the slide back in, as it only goes one way, or, it will hold the throttle open and scare the crap out of you when you start it! :eek:
 

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Discussion Starter · #5 ·
LOL ill try that.
 

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Discussion Starter · #6 ·
Ok I am like totally confused I took the thing off and it pulled a spring out with it so I said I aint screwin with this so I put it back to together you dont think it could be anything else than that. Or give me other things I can try.
 

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That is the thing to 'screw' with!

Take the whole assembly out of th carb and very carefully remove the throttle cable from the black slide. Don't bend the needle while doing it. Be patient because the spring makes it somewhat complicated to remove the cable, but, not that difficult.

Once you have disconnected the cable the spring and the black slide will separate from it. Carefully turn the black slide upside down and a split washer and the needle will fall out. Again, be very careful when removing the c-clip because they can fly a mile and are impossbile to find on a dirty floor! Reset the lcoation of the clip and carefully reassemble everything. It may look complicated, but, shouldn't take more than about 5 minutes to do!

If you drop it down to the bottom notch, it might be too rich, but, at least you will have fixed the bog. Fine tune it later if it smokes too much.

Don't be intimidated, just dive in. It's the only way to learn!
 

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Discussion Starter · #8 ·
Ok thanks I am going down there to do it right now.:)
 

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Discussion Starter · #9 ·
Ok so I did all that I put the c clip on the 2nd ti the bottom notch but now the big metal thing is so hard to screw back on to the carburator because the spring is pushing against it how can I get it on.
 

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Ok, now make sure that the black slide is in properly. make sure that the little 'ramp' on the bottom of the slide is lined up with the idle stop screw on the left hand side of the bike. If the slide is all the way to the bottom, the spring should be easier to compress.

I have one bike where the spring tension is still pretty hard; on that one it helps to open the throttle a wee bit (turn the throttle grip) which compresses the spring a bit. The caps are a bit hard to hold on straight because of the cable, but, work at it and it will go right on.
 

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Discussion Starter · #11 ·
Ok I did it all and like you said it will hold the throttle open if the slide is on wrong what should I do.
 

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I don't quite understand what you are asking this time. Did you put it in wrong? If the cap is threaded back on, can you open and close the throttle? If not, then you didn't get the slide back in correctly. When the slide is first slid into the carb, rotate it slightly (making sure that the 'ramp' is aligned with the idle stop screw) and it should drop right in.

Check the FAQ area; I would image there are pictures of these parts floating around.
 

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Discussion Starter · #13 ·
Should the black thing go all the way down in the hole or should it stick out a little bit.
 

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The 'black thing' is called the throttle slide. It is the actual valve the controls the air/fuel rate into the engine to control the speed of the engine!

The needle (brass pin) must align with the main jet (tiny hole in the bottom of the slide bore). The slide (black thing) Must be oriented correctly with both a notch in the bore AND the 'ramp' to the idle stop screw. Make sure that you wiggle it back and forth until it drops all the way down and in. Yes, it needs to go completely down and in!

If you want to be completly sure, take your air filter off and look down the venturi (hole through the carb into the engine). In order to idle the slide MUST be able to close. It won't close completely because that is what the idle stop screw is doing when it engages the 'ramp' in the slide, but, wide open is bad, but, lots of fun to watch when you try to start it!!! :)

Really, once you get the idea of how a 'differential pressure' carborator works, it is pretty simple. With practice you will be able to make this adjustment on the side of the road in 5 minutes!
 

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Discussion Starter · #15 ·
Ok now the bike runs but only when the choke is on when I switch the choke off it just dies.
 

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Let's check the basics first: is there enough gas in the tank? Is the fuel on? Did you remove the carb or loosen any of the screws/bolts? Did you put the air filter back on? Will it run if you give it some throttle? If so, did you touch the idle screw?

Are you sure you moved the c-clip down towards the pointed end of the needle?
 

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yeah sounds like you moverd the needle the wrong way. if it wont run without the choke that means that you definitlyaint getting fuel cause with the choke on you are forcing fuel in and when you turn choke off the bike dies. meaning no fuel. so take it back off and make sure you dropped it towards the pinted end of needle.
 

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Discussion Starter · #19 ·
Ya the needle is in right but it seem that the idle screw is doing nothing when I turn it.
 

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Discussion Starter · #20 ·
Any other ideas how can I get more gas and air to the carburator?
 
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