Two Stroke Choke

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jstcraig
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Two Stroke Choke

Post by jstcraig »

Have give this carb an ultrasonic clean replaced the seals, running 42/122 and two down on the needle, all the jets had a tip cleaner and air run through them before assembly, wasn't sure what height to set the needle jet so the middle looked the best option. The pilot air screw is at 1.5 turns.
It only runs with the choke on and when off the revs increase till it cuts out.
I have sweet FA experience with 2 stroke carbs and read somewhere that the choke adds air ??? So leans the mix, is this right could it be too rich, that wouldn't explain the rev increase when the choke is pushed in. So I'm confused quite happy to except that I missed something and will re check the internals but would appreciate the input of the more experienced.
Cheers


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SS109
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Two Stroke Choke

Post by SS109 »

The choke circuit introduces more fuel to the system. Sounds like the pilot circuit is plugged up somewhere.
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jstcraig
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Two Stroke Choke

Post by jstcraig »

Well at least my initial thoughts were correct, considering the rev increase when I shut the choke off, the jets and needles are clean so it must be the body passages another few hours in the ultrasonic and get it nice and hot, any thoughts on the needle jet height setting, there is a vid of it running on the SR page if your interested give me your impression, CheersImage
This is the plug after about 1.5 liters of fuel through the engine
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Two Stroke Choke

Post by SS109 »

Sounds off for some reason. Clean air filter? No leaks at the intake manifold or air box/junction? Fresh premix?
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Current KDX: '98 KDX220
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jstcraig
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Two Stroke Choke

Post by jstcraig »

Yes all new boots and filter, double checked the manifold, will remove the pre filter or could it be to much oil in the air filter ?, might pull it and give it another squeeze, the filter oil seem a little heavy, the exhaust doesn’t seem to be sitting exactly right as it had a few belts is it possible that the flange gasket is leaking ?? Would that cause issues ?


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jstcraig
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Two Stroke Choke

Post by jstcraig »

re did the carb runs with out choke now, played around with needle jet height but seems to be too lean, will tilt it and redo the needle placementsImage
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Re: Two Stroke Choke

Post by jstcraig »

Nope that didn’t work,still can’t get the idle under control


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Re: Two Stroke Choke

Post by KDXGarage »

What did you do on the reeds?
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Re: Two Stroke Choke

Post by jstcraig »

Jason wrote:What did you do on the reeds?
Left the standard reeds in at the moment


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