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LONG STORY SHORT, carb brute hard to start. NOT valves.

Okay so background. I bought a 500 dollar brute that needed rebuilt. I rebuilt it. Its an 05 brute 750 with a 3/4 HMF and 11.5 wiseco pistons.
Its got 38 pilot jets front and rear. The main jets are 158 front and 160 rear with non adjustable needles. I just got its put back together and drove it for the first time today.

My problem is its a 5-10 min process of starter turning to get it to run. choke no choke it seems like it doesn't matter. spark is good, fuel volume is good, compression is good. once it runs its good, well as far as i know i have the throttle limited to about 1/4 throttle to break in the motor. the motor has less than an hour and probably about 1 mile on it. I have checked the valves twice. That seems to be a common answer. I am just at a loss. Whats weird is it seems like instead of fuel coming from the main jet side, it seems like fuel is coming from the diaphragm side of the carb. Never seen anything like it and i have worked on many atvs.

The weirder thing is that the first time i started it, it hit immediately then fired seconds after that. Ever since then it has been a 5-10 min process to get it to fire.
 

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couple things could be, stock tune is not going to work, you are going to have to richen everything because of the exhaust and higher compression, the idle screws if you set those to the manual it not going to be even close probably close to three or higher i would start, if it runs you can warm it up, turn the idle knob down turn the screws till the adjustment makes it worse. then make them the same. after that would put some shims on the needles. after you get the idle and low adjusted you will likely need bigger main jets. i did that last and by max speed then a bit richer to be on the safe side
 

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The hard starting has nothing to do with tuning. The choke adds fuel to start, the rest of the carb circuits don't matter.
Spark at the plug.
Compression.
Fuel to the combustion chamber.
You need all three.

Sort out the carbs; it sounds like they may be assembled wrong, or the float is too high or sticking. Or maybe it's just the fuel coming from the enrichener jets.
The enrichener jets (chokes) are working; not seized in the carb?

Did you actually check the compression with a gauge? It "feels good" doesn't cut it.
You said it's getting fuel. Fuel to the carbs, or actually getting fuel going to the engine?

Did you pull the plugs to see if they're wet when it won't start?
Did you dump a little gas down the carbs if the plugs were dry?
What were the compression readings?
 
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