LF right setting on carb for YZ490

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dm_js - 04 Jan 2007 02:25 GMT

Looking for the right setting on set screws for 1982 YZ490 2 stroke yamaha.
How many turns for air and gas???

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e - 04 Jan 2007 04:16 GMT

>Looking for the right setting on set screws for 1982 YZ490 2 stroke yamaha.
>How many turns for air and gas???

turn till it starts to rev, then back off till it idles
smoothly. rev with the throttle and see if it settles down
to the same revs. after 100 miles check the plug.
easiest and best way i've found.

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dm_js - 05 Jan 2007 02:40 GMT

I just installed a used carb and the set screws were turned in all the way.I
just need to know how far to turn them out so I can get it started...
I can adjust it after its running.

>>Looking for the right setting on set screws for 1982 YZ490 2 stroke
>>yamaha.
[quoted text clipped - 4 lines]
> to the same revs. after 100 miles check the plug.
> easiest and best way i've found.

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Fred W - 05 Jan 2007 02:49 GMT

> I just installed a used carb and the set screws were turned in all the way.I
> just need to know how far to turn them out so I can get it started...
> I can adjust it after its running.

Ummm. A little?

Start with 1 1/2 turns. Tune from there. Try using a Color-tune if you
can get your hands on one. I had great success on a 4 cyl Kawi motor
getting the pilots set right using one of them.

Signature

-Fred W

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e - 05 Jan 2007 04:15 GMT

>I just installed a used carb and the set screws were turned in all the way.I
>just need to know how far to turn them out so I can get it started...
[quoted text clipped - 8 lines]
>> to the same revs. after 100 miles check the plug.
>> easiest and best way i've found.

you need the manufacturer's specs' try google.

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Motorcycle Forum / General / Yamaha / January 2007

LF right setting on carb for YZ490