1983 YZ125 power valve

leisure67
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leisure67
Edited Date/Time 5/17/2013 3:22am
Hey everyone,
Recently bought an '83 YZ125 that had no top end power. Found that the power valve was not functioning & badly worn in several places. Anyone know where I could find one? Need the valve & the linkage but the governor is fine.
Appreciate any help.
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Halfast816 5/7/2013 7:33am
5/7/2013 7:33am
Give Lee a call at On the Pipe Racing he is in the Merrill area and restores 80's MX bikes. 715-370-2992
leisure67
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leisure67 5/7/2013 7:51am
5/7/2013 7:51am
Halfast816 wrote:
Give Lee a call at On the Pipe Racing he is in the Merrill area and restores 80's MX bikes. 715-370-2992
Thanks.
I sent him an email prior to posting this but haven't heard back from him. Will call.
husky125
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husky125 5/7/2013 9:33am
5/7/2013 9:33am
Another place you might want to try is Action Sport Cycles in Alliance, Ohio. They are known for stocking older YZ and RM stuff.
330-821-8777 and ask for Shawn.
leisure67
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leisure67 5/7/2013 10:33am
5/7/2013 10:33am
husky125 wrote:
Another place you might want to try is Action Sport Cycles in Alliance, Ohio. They are known for stocking older YZ and RM stuff. 330-821-8777 and...
Another place you might want to try is Action Sport Cycles in Alliance, Ohio. They are known for stocking older YZ and RM stuff.
330-821-8777 and ask for Shawn.
Will try them as well.
Thanks!

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project racer 5/7/2013 4:02pm
5/7/2013 4:02pm Edited Date/Time 5/7/2013 4:25pm
Any Yamaha dealer that has the Lightspeed program on their computer system can run the part numbers you are seeking. The search will show any and all dealers that have them in stock. The only glitch is when a part number drops off of the price file, it won't show up on the search, even though some dealer may have 10 of them on the shelf.

And be sure to get the two little dots lined up on the PV. There is one on the valve end, and the other is on the linkage plate that attaches to the valve. It will run in either position, but if the marks are off, the valve is 180 degrees out of phase.

The valve is then operating exactly opposite of the way it is designed to. Top end power will be non existent. Be sure to Loctite the center allen screw that holds the valve halves together.
leisure67
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leisure67 5/8/2013 3:42am
5/8/2013 3:42am
project racer wrote:
Any Yamaha dealer that has the Lightspeed program on their computer system can run the part numbers you are seeking. The search will show any and...
Any Yamaha dealer that has the Lightspeed program on their computer system can run the part numbers you are seeking. The search will show any and all dealers that have them in stock. The only glitch is when a part number drops off of the price file, it won't show up on the search, even though some dealer may have 10 of them on the shelf.

And be sure to get the two little dots lined up on the PV. There is one on the valve end, and the other is on the linkage plate that attaches to the valve. It will run in either position, but if the marks are off, the valve is 180 degrees out of phase.

The valve is then operating exactly opposite of the way it is designed to. Top end power will be non existent. Be sure to Loctite the center allen screw that holds the valve halves together.
I have found them thru Yamaha but didnt want to spend that much on it. A big reason I was thinking about a used one is because I will also need the linkage that goes to the governor. The spot where it attaches to the power valve is worn badly.

Appreciate the tip on the dots... I did not know about that.

LOCTITE!!!!! The previous owner did not use it on that allen screw which is what ruined the power valve I have now. The threads for that screw are stripped out & the hole is out of round. The holes for the alignment pins are also egged out.

Think I may follow your advice about just buying a new power valve & looking for the linkage used.

Thanks for your help!
leisure67
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leisure67 5/8/2013 4:53am
5/8/2013 4:53am
Looks like the reason for the linkage being loose where it attaches to the power valve is because it is missing a piece part. Part # 26 (boss,collar) is MIA which would explain why it wore out.
leisure67
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leisure67 5/9/2013 3:40am
5/9/2013 3:40am
Ordered the new parts. Will see how tight the linkage is with the new parts.
Thanks for the help guys.


Yamaha Motor - 5X4-1131A-00-00
VALVE 1 $117.66 1
On Order Scheduled to Ship Friday MAY 10, 2013(due from manufacturer)
Ship Method FEDXGR

Yamaha Motor - 5X5-11937-00-00
BOSS,COLLAR $7.53 1
On Order Scheduled to Ship Friday MAY 10, 2013(due from manufacturer)
Ship Method FEDXGR

Yamaha Motor - 93104-16074-00
OIL SEAL,SO-TYPE $9.35 1
On Order Scheduled to Ship Friday MAY 10, 2013(due from manufacturer)
Ship Method FEDXGR

Yamaha Motor - 932Yamaha Motor - 09192-00
O-RING $4.02 1
On Order Scheduled to Ship Friday MAY 10, 2013(due from manufacturer)
Ship Method FEDXGR

Yamaha Motor - 932Yamaha Motor - 270A8-00
O-RING $4.97 1
On Order Scheduled to Ship Friday MAY 10, 2013(due from manufacturer)
Ship Method FEDXGR
berniepiet
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berniepiet 5/11/2013 10:29am
5/11/2013 10:29am
I don't know if you need anything else, but I have and entire 1984 that is disassembled. Let me know if there is anything you need.
leisure67
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leisure67 5/12/2013 1:14am
5/12/2013 1:14am
Need a set of foot pegs & a kick starter. Pretty complete other than that.
Need a seat for the '81 too if you happen to have one... or parts of one?
Give me a call.

Thanks!
daven83
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daven83 5/16/2013 5:28am
5/16/2013 5:28am
Try Beach Yamaha in Huntington Beach Calif.....ask for Greg (owner)...i know they have a ton of older YZ parts in stock because they bought them from the dealership i used to work at years ago.
leisure67
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leisure67 5/17/2013 3:22am
5/17/2013 3:22am
daven83 wrote:
Try Beach Yamaha in Huntington Beach Calif.....ask for Greg (owner)...i know they have a ton of older YZ parts in stock because they bought them from...
Try Beach Yamaha in Huntington Beach Calif.....ask for Greg (owner)...i know they have a ton of older YZ parts in stock because they bought them from the dealership i used to work at years ago.
I did order all the new parts listed above & should get most if it delivered on Saturday. They still haven't gotten the BOSS, COLLAR so I dont know when I will get that. I'll give Beach Yamaha a call & see if they have that part.

Thanks for the help!!

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