99 YZ 125 restore pictorial


285 replies to this topic
  • pvangel

Posted 30 August 2011 - 11:16 AM


No power for 3 days now...sucks!
The power valve is pretty much worn out at this point, gonna do a Macgiver on it tonight to try and have it ready for races this Saturday...We'll see

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  • pvangel

Posted 30 August 2011 - 05:07 PM


So I have no power,no phone no tinternet but I got the 99 back together with spit and glue... Pics to follow when I get power back but I have to say I even impreessed my self with this repair...

  • BDubb106

Posted 31 August 2011 - 03:36 AM


Good job man, impressive to get it done with no power. How the hell could you see what you were doing?

  • pvangel

Posted 31 August 2011 - 04:55 PM


just got power back after 5 days....



So the 99's powervalve was hitting the piston  and not opening beacause the springs that actuate the valves are so worn that they grab the shaft instead of pulling them open and closed. I did grind the face of the powervalves to insure that there was clearance between them and the piston. I tried to order new springs but could not get them in time for this weekends race.



Here are the tops of the powervalves without the linkage and springs installed,



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Here is a brass tube that i am putting over them to increase the diameter as well as get rid of the ridges worn in from the springs,



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Here it is assembled but was still kinda loose



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So I cut 2 washers to fit as shims on the outside to keep the springs straight,



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Put it all back together and it ran great up and down the road! Hopefully it will last the day at Raceway park in Englishtown,NJ

  • pvangel

Posted 31 August 2011 - 05:09 PM


After all my bad luck this year with motors i did spend the time we had with no power to construct a shrine to the gods above...

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Not my idea as I saw it elswhere but figured it couldn't hurt...

  • Tick51

Posted 31 August 2011 - 06:03 PM


Good thinking mine have that spring pitting also,let us know next time you inspect for ware.my guess is it will hold up for the day and tightens up all spring slop




 
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