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Author Topic: 82 YZ490 carb issues  (Read 5606 times)

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Offline silverfox

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82 YZ490 carb issues
« on: December 03, 2013, 10:20:37 pm »
Thinking the carb is crook on this 490. Whats a good carb for it?? might have to buy a new one. Also any jetting tips??? recommendations? Will pull this one apart again, but seems to be missing bits!! As it had no Baffell/ washer part under the main jet. Put a new float in it, but will not run without the choke on. Starves for fuel!!
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To many, 72 Husky CR400, 73 Husky CR250, 77 RM370 x 2, 77 & 79 Honda CR125, 77 AW400, 82 CR480, 87 430 auto, 79 Honda 500/ Husky hybird

Offline evo550

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Re: 82 YZ490 carb issues
« Reply #1 on: December 04, 2013, 09:14:20 am »
check your pilot circuit, sounds lean. Maybe a blockage or wrong pilot jet.
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Offline Gerard De Ruyter (Twistandshout)

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Re: 82 YZ490 carb issues
« Reply #2 on: December 04, 2013, 04:17:02 pm »
My TT250 was doing that - found the float level was too low - pilot couldn't access the go fast stuff.
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Offline silverfox

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Re: 82 YZ490 carb issues
« Reply #3 on: December 04, 2013, 07:29:30 pm »
I will check the float level. Thanks
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To many, 72 Husky CR400, 73 Husky CR250, 77 RM370 x 2, 77 & 79 Honda CR125, 77 AW400, 82 CR480, 87 430 auto, 79 Honda 500/ Husky hybird

Offline mitch75

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Re: 82 YZ490 carb issues
« Reply #4 on: December 08, 2013, 08:28:03 pm »
chuck a new needle and seat in before you go adjusting float levels.
http://www.mikunioz.com/
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Offline tony27

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Re: 82 YZ490 carb issues
« Reply #5 on: December 08, 2013, 09:25:09 pm »
Float needle & jet was first thing I did when sorting my 465 although that was to cure a richness problem.
If you need a baffle for above the main jet I have a carb for a 250j that I bought for spares that I could take it out of, most internal parts are common to round slide mikunis from what I've seen
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Offline silverfox

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Re: 82 YZ490 carb issues
« Reply #6 on: December 08, 2013, 09:42:07 pm »
Cheers. I have a baffle to put in it, but it seems like I need a longer threaded main as it will not reach the tube. Tube is all the way down. All a bit strange but will get to look at it again later in the week
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To many, 72 Husky CR400, 73 Husky CR250, 77 RM370 x 2, 77 & 79 Honda CR125, 77 AW400, 82 CR480, 87 430 auto, 79 Honda 500/ Husky hybird

Offline kim80y

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Re: 82 YZ490 carb issues
« Reply #7 on: December 09, 2013, 08:55:43 pm »
Just get a new carb fom Mikuni oz, YZ490 yahoo forum has all the jetting specs for each model.
Or if you need them PM me and I will copy and send to you, they will be a good baseline.
It will work out cheaper and less hassle to get a new carb.

Cheers
Kim ;) ;) ;)
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Offline Sorelegs11

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Re: 82 YZ490 carb issues
« Reply #8 on: December 10, 2013, 09:22:47 am »
Could have the wrong {shorter} neddle jet in it
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Offline silverfox

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Re: 82 YZ490 carb issues
« Reply #9 on: January 04, 2014, 08:10:12 pm »
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To many, 72 Husky CR400, 73 Husky CR250, 77 RM370 x 2, 77 & 79 Honda CR125, 77 AW400, 82 CR480, 87 430 auto, 79 Honda 500/ Husky hybird
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