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Discussion Starter #1
I've been searching all over for solutions to this problem. I have a 2006 Sportsman 450 that I can't get to run right. I bought the machine with a bad motor and replaced it with a used eBay one. It was said to be in good running condition. After putting it in, it fired up pretty quickly. The previous owner had installed a new Chinese carb. It wouldn't rev up much at that point. So I ordered a carb rebuild kit for the original carb that came with it, and went to rebuild it but the floats were cracked and I can't seem to find replacement oem ones. So I ordered another Chinese carb and rejected it with my new carb kit, except for the top jet under the diaphragm because it had a different thread size. Anyways, i put the carb back on and it still doesn't want to rev up all the time. It does always idle almost perfectly and starts great even when cold. It just bogs out some of the time when applying the gas, and won't rev up. It seems like if I give it a shot of carb cleaner in the intake, it will run great for at least a few minutes. Any ideas?
 

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When you open the throttle, you give the engine AIR - it's the job of the carb to mix fuel with the air - the carb needs calibrated by an experienced tuner - the problem is the Chinese carbs do not have the same size air passages, so installing jets for the OEM carb does not provide for the correct fuel to air ratio - the jets may need to be larger or smaller than the OEM carb to attain the correct mix - one Chinese may need larger than what it comes jetted at and the next may need smaller jets.

The OEM float is part 3130529 abd is available through Polaris
 

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Discussion Starter #3 (Edited)
I see what you're saying on the Chinese carbs, I have never trusted them and never used one until now. Maybe I should go back to the Jets it came with?

Either way, the main symptom I'm seeing is it does not want to rev up from 1300-2750 but if you can get it to sputter up past about 2750 then it seems to run good. Also, when it bogs out, it pops out of the air intake.

Also, if I give it a shot of brake cleaner, it revs up fine.
 

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When you get a backfire out of the intake, it is a classic indication of being lean in that area - you might try raising the slide needle a notch if it is adjustable - if it is not adjustable, find a small washer and shim it up a washer or two to see what change that makes. The thing about carbs is they are not easy to get to and you can only make one change at a time - if you make more than one change and it doesn't run right which change made the undesirable effect and which change are you going to reverse?
 

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Discussion Starter #6
Thanks a lot-I just tried that last night. Moved the clip down one position, ran better, then down another, and it runs like I think it should!
 

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Discussion Starter #8
Not likely! Lol

It's right around 32 degrees here in Illinois, and upon starting it today I noticed it takes around 3-5 minutes for it to warm up and get completely rid of that bogging. Is this normal, and is there any possibility that I could make another adjustment to make that work better? Or is that just time needed for it to warm up?
 

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Warm up is necessary, but because the carb has an enrichener instead of a choke, you can just take off with the enrichener on - it becomes ineffective above between about 1/3 and 1/2 throttle - just run with it on for the first 3 to 4 minutes - it will actually warm up faster by running it and not just letting idle.

My CRF need about 5 minutes of fast idle followed by about 3 minutes of running with the enrichener on before it will run without bogging and it has an accelerator pump on the FCR carb.
 

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Discussion Starter #10
Sounds like I'm in business then! This is the first machine I've owned with this kind of carb. I've had about a dozen different quads over the years but never did mess with the carbs much. The race bikes with FCRs I had dyno-tuned by the local race shop.
 
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