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
99 YZ 125 restore pictorial
Started by
pvangel
, Jan 26 2011 07:53 AM
285 replies to this topic
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?
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,

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,

Here it is assembled but was still kinda loose

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

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
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,

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,

Here it is assembled but was still kinda loose

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

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
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









