2018 CRF50 idle issues. Please help

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10/16/2017 7:33 PM
Edited Date/Time: 10/16/2017 7:34 PM

So my sons 18 crf50 has never idled correctly since brand new. It will idle ok when cold but once warm it will die if it sits for more than say15 seconds. It’s a pain when trying to stop him to talk or help him and if he doesn’t keep the bike going with the throttle, it will just Peter out. I have tried to adjust the idle screw. It either dies or the idle slowly runs away into the high RPMs. The dealer won’t help. Bike is outside of the warranty. I removed the carb and cleaned it with carb cleaner. It looks new. Bike maybe has 6 hours on it. I’m at a loss.

I even swapped out the whole stock filter assembly for a UNI filter. No change. The bike runs strong and doesn’t bog. Just won’t idle for shit. Any ideas??

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10/16/2017 8:30 PM

Did you turn the fuel screw on the bottom of the carb? It takes a special "d" tool

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Tomac and/or Anderson for 2020.....

10/16/2017 9:18 PM

Pilot jet might be plugged with grit. Pull it out. Blast air and carb cleaner or brake cleaner through it. You should see daylight through it.

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10/17/2017 6:20 AM

garagedog wrote:

Pilot jet might be plugged with grit. Pull it out. Blast air and carb cleaner or brake cleaner through it. You should see daylight through it.

I pulled the carb apart last night. Blasted carb cleaner into every hole I could find. It sprayed out perfectly through the whole carb. I have no idea what Im doing. There is only the idle screw on the side. There is another brass looking screw-ish thing below the idle screw. But it has no head on it to turn it. No phillips or flat head marks. Its just a hole with a brass insert.

Was there supposed to be a screw in there?? Doesnt look like there should be. Im frustrated here and ready to pay the dealer to work it out.

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10/17/2017 10:24 AM

the dealer wont fix it they dont know how or cant because ur air screw has an insert over it so it cant be adjusted from the factory, we drill thee out on street bikes all the time, ive never drilled one out of a 50 cuz i have had old carbs laying around that had adjustable air screws, and i would just throw one on, you need to try and drill out the brass plug over the screw, if u screw it up buy a carb with an adjustable air/fuel screw

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10/17/2017 11:32 AM

Likely a clogged pilot jet. Your bike has the symptoms. The pilot jet on these has a hair-thin opening that clogs with the slightest amount of varnish. Always add Sta-Bil or other ethanol equalizer to the gas for this reason. Also, this bike is very cold blooded and very sensitive to choke position. I can never open my choke fully. Usually only get to about half way. And that is even at 5,000 ft elevation where you'd think it would already be rich.

The pilot jet on these is actually a pressed in brass tube. I have always had luck just blowing it out with carb cleaner using the red straw on the aerosol can. This guy actually shows how you can remove the brass tube but I have never needed to remove it. Just cleaned mine the other day.

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Powerband in every gear !

10/17/2017 3:19 PM

FGR01 wrote:

Likely a clogged pilot jet. Your bike has the symptoms. The pilot jet on these has a hair-thin opening that clogs with the slightest amount of varnish. Always add Sta-Bil or other ethanol equalizer to the gas for this reason. Also, this bike is very cold blooded and very sensitive to choke position. I can never open my choke fully. Usually only get to about half way. And that is even at 5,000 ft elevation where you'd think it would already be rich.

The pilot jet on these is actually a pressed in brass tube. I have always had luck just blowing it out with carb cleaner using the red straw on the aerosol can. This guy actually shows how you can remove the brass tube but I have never needed to remove it. Just cleaned mine the other day.

X2....Those little holes will become clogged from dry gas and still look open. Just spraying them and blowing will not clear them. Either get a new jet or run a very fine wire through each hole.

Paw Paw

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