TY250D carby issues

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cwilson
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TY250D carby issues

Postby cwilson » Sat May 11, 2019 5:24 pm

I have picked up a TY250D that doesn't idle or run well without the choke on. can anyone recommend a bike mechanic in Sydney to get it running nice or any simple things to try I'm not up to speed on jetting etc.


-Chris Wilson

David Lahey
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Re: TY250D carby issues

Postby David Lahey » Sat May 11, 2019 8:59 pm

The symptoms sound like the pilot jet is probably blocked. This is a fairly common problem if a bike has been sitting for a while with fuel left in the float bowl. The fuel turns into a gummy residue over time. Pilot jets have a tiny hole for the fuel to go through and so the gum blocks them very easily.
To clean it out you will need to take the bottom section off the carby.
Any motorcycle mechanic would be familiar with this issue and be able to fix it easily.


relax, nothing is under control

JimsShed
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Re: TY250D carby issues

Postby JimsShed » Tue May 14, 2019 6:56 pm

If the carby clean doesn’t fix the problem then it’s likely you have a vacuum leak. Commonly, the crankshaft seal under the magneto will need replacing. A leaking seal will cause it to run lean, hence the need to use the choke. Regardless, any Yamaha dealer can fix your problem.



cwilson
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Re: TY250D carby issues

Postby cwilson » Sat May 18, 2019 11:10 am

Thank you I have cleaned out the Carby and jets seem clear. It only dies on idle now, it revs fine when throttle is open but dies as soon as the rpm gets down to idle. Only idles with choke on any suggestions?


-Chris Wilson

David Lahey
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Re: TY250D carby issues

Postby David Lahey » Sat May 18, 2019 12:04 pm

Have you set the idle mixture screw and set the throttle slide stop position?
Usually about 1.5 turns out from fully in for the screw and turn the slide stop screw inwards (lifts the slide) until it idles.
If there is still some junk in the pilot circuit, you will still have a problem at low throttle openings


relax, nothing is under control

cwilson
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Re: TY250D carby issues

Postby cwilson » Mon May 20, 2019 5:12 pm

Thanks - got it idling better it must have been the pilot jet I found it finally and it was blocked - I was previously looking at the wrong jets!


-Chris Wilson

David Lahey
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Posts: 3377
Joined: Thu Jun 05, 2003 7:01 pm
Bike: Many Twinshocks
Club: CQTC Inc, RTC Inc
Location: Gladstone, Queensland

Re: TY250D carby issues

Postby David Lahey » Mon May 20, 2019 8:34 pm

Excellent


relax, nothing is under control


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