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Discussion Starter · #1 ·
I have a 1987 Honda 250x. It has mild performance mods: mild cam, K&N filter, full exhaust, jetted at 130 main and 42 pilot. The needle is in the middle groove.

This winter I rebuilt the carburetor and have had fuel problems ever since. I have stripped down the carb multiple times and everything was in order. I have taken apart and cleaned the petcock and also replaced the o-ring in it. I replaced my in-line filter as well. The ATV starts, but only runs on choke. The idle is also high like it is sucking in air. I have double and triple checked both the boot from the airbox and the boot going into the jug. I even replaced the o-ring behind the boot on the jug. There was no change. The last thing I can think of is that the valves are out of adjustment.

Anyone have any other ideas? Maybe something I have over looked?
 

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To me it sounds more like u have a air leak...could be a bad head gasket...if itll only run on choke .....the valve lash is easy to check and should be .004 both intake and exhaust...if the exhaust valves r open a tiny bit could cause the problem u described
 

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How did you clean the carb?? Sounds like to me the idle circuit has some trash in it. Try screwing the fuel/air mixture screw in, if the engine tone dosen't change I would lay a good bet on the idle circuit. Also check to make sure your cable is on the throttle cam where it should be underneath the black cover. It's not common for an intake boot to leak air unless the o-ring is bad I have carb boot in my spare parts that are older than alot of our members. lol that are still in great shape.
 

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X2, sounds like the idle circuit may be clogged.
 

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Discussion Starter · #5 ·
How did you clean the carb?? Sounds like to me the idle circuit has some trash in it. Try screwing the fuel/air mixture screw in, if the engine tone dosen't change I would lay a good bet on the idle circuit. Also check to make sure your cable is on the throttle cam where it should be underneath the black cover. It's not common for an intake boot to leak air unless the o-ring is bad I have carb boot in my spare parts that are older than alot of our members. lol that are still in great shape.
Moose, I replaced the O-Ring in the boot and that didn't change it. When I cleaned the carb I had it all disassembled and sprayed it thoroughly with carb cleaner and let it dry before reassembling. If there was any carbon or gunk built up in some parts I took very fine 600 grit sand paper and lightly scrubbed it off before spraying it again with carb cleaner. I'd put money on it that I didn't get all of the gunk out and maybe something got plugged up. I don't have my manual in front of me, but what is the idle circuit? Correct me if I'm wrong, but I'm going to assume that it is the slow jet?
 

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Yep, the idle circuit consists of the slow jet and the passageway in the carb body that the slow jet screws into. The idle circuit starts with the slow jet and exits in the throat of the carb, just in front of the throttle plate. If you look closely you can see the small hole. Also, the tip of the pilot screw protrudes into the passageway to regulate the fuel flow through the passageway.
 

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Discussion Starter · #7 ·
Yep, the idle circuit consists of the slow jet and the passageway in the carb body that the slow jet screws into. The idle circuit starts with the slow jet and exits in the throat of the carb, just in front of the throttle plate. If you look closely you can see the small hole. Also, the tip of the pilot screw protrudes into the passageway to regulate the fuel flow through the passageway.
All right. if my truck parts don't come this weekend I'll have to give it a closer look and maybe hit it with some compressed air breaks anything loose if it is in there. The only other thing I can think of is the rebuild kit I got had a replacement for every o-ring in the carb and maybe its sucking air in through one of them.
 

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I have a 1987 Honda 250x. It has mild performance mods: mild cam, K&N filter, full exhaust, jetted at 130 main and 42 pilot. The needle is in the middle groove.

This winter I rebuilt the carburetor and have had fuel problems ever since. I have stripped down the carb multiple times and everything was in order. I have taken apart and cleaned the petcock and also replaced the o-ring in it. I replaced my in-line filter as well. The ATV starts, but only runs on choke. The idle is also high like it is sucking in air. I have double and triple checked both the boot from the airbox and the boot going into the jug. I even replaced the o-ring behind the boot on the jug. There was no change. The last thing I can think of is that the valves are out of adjustment.

Anyone have any other ideas? Maybe something I have over looked?
you need to change the setting on the needle valve go 1 lower and that should fix it
 
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