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Sy 250 With Sticky Choke Plunger

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I don't mean to be so prolific here, but the choke plunger on my SY250 is an absolute bear to bring up into the choke position. It requires me crouched beside the bike, using both index fingers on either side of the button, and pulling up hard until, maybe, click, it goes, or not. Very difficult.

First, I lubed it with some WD-40, which may have helped, a bit. Then I disassembled it, and cleaned it (with the rest of the carb ala tailgate - haha) which only made it worse.

Does anyone have any ideas?

Thanks in advance.

Edited by TrialsRyder

  • Author

I cleaned the carb completely. I am confident it is clean.

I believe my problem was fuel still in the cylinder thus fouling the plug. I left the plug out for a couple days to allow the fuel to vaporize.

Today, cylinder dry, fresh plug, no spark with new plug againt head. Assembled, will not start or give any hint of starting. I am beside myself.

Edited by TrialsRyder

Stick it in 4th or 5th plug out spin the engine by turning the back wheel by hand. Easier to see the spark. :D

Failing that check all the connections, wires etc. :blush:

  • 2 weeks later...

My choke is very stiff to lift aswell, i'm having problems with over use of fuel whilst it is running engine is very fluffy at low revs and empties the tank after about 4 miles of running. Like yours carb has been stripped and cleaned. going to have another look at it to see if anything worn.

I can do a trial on about 2 or 3 litres of fuel, no idea what that is in miles though, we usually run 5 laps of 8 sections.

My choke lever is quite stiff too. Plug needs to be cleaned after every other trial stalls unexpectedly otherwise.

Edited by BigMike1961

  • Author

I disassembled the carb again and lubed the choke mechanism with some 2 stroke oil. My choke is working better now. My bike is still not starting (see other post) and I believe the problem is with the float-valve needing replacement - which I am working on.

Robdyson: You might want to check your float height measurement. It could be you have too much fuel in your float bowl (float level too high). I believe this would cause fuel to constantly be flowing out the overflow breather tube, thus the poor fuel economy. Just a thought. Others may have a better answer.

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