Other 1993 Yamaha WR500 Top End Inspection
- Thread starter SRAD97750
- Start date
Measured the lower rod bearing play and found 0.000"
*This is a photo of the set-up, not the test itself.*
Also took a wire brush to the crown and green scotchbrite to the skirt. Came out lookin' nice.
Still undecided...
Run another 40 Hours? ($34 for gasket kit, pin, bearing, clips.)
Wait on a new piston kit? ($99.96 for kit, gasket kit, bearing.)
I will be purchasing this piston kit I found, regardless. 40Hrs is almost no time at all.
But, I would also lose sleep wasting a perfectly good piston based on hours alone...
-BIG DAN
*This is a photo of the set-up, not the test itself.*
Also took a wire brush to the crown and green scotchbrite to the skirt. Came out lookin' nice.
Still undecided...
Run another 40 Hours? ($34 for gasket kit, pin, bearing, clips.)
Wait on a new piston kit? ($99.96 for kit, gasket kit, bearing.)
I will be purchasing this piston kit I found, regardless. 40Hrs is almost no time at all.
But, I would also lose sleep wasting a perfectly good piston based on hours alone...
-BIG DAN
Measured the lower rod bearing play and found 0.000"
*This is a photo of the set-up, not the test itself.*
View attachment 24937
Also took a wire brush to the crown and green scotchbrite to the skirt. Came out lookin' nice.
View attachment 24934
View attachment 24935
View attachment 24936
Still undecided...
Run another 40 Hours? ($34 for gasket kit, pin, bearing, clips.)
Wait on a new piston kit? ($99.96 for kit, gasket kit, bearing.)
I will be purchasing this piston kit I found, regardless. 40Hrs is almost no time at all.
But, I would also lose sleep wasting a perfectly good piston based on hours alone...
-BIG DAN
There's a lot of hours on that piston already. $140 is worth it to me and with pistons it isn't what you see it's what you can't see that scares me. Isn't that why they X-ray airframes?
It's your call buddy but from one friend to another swap it out.
Replace the piston. Just about aspect of a piston is engineered. What I see missing is the surface texture on the sides. The function is to retain lubricant. On the first as removed pic it appears to have been worn off over a lot of the sides. Looks to be almost all gone in after the wire brushing.
That said, you could just run it. On a two stroke it might just cause a tiny amount of excess wear.
A lot of times surface discoloration is just visual. I use the measuring devices, but sometimes simply running your fingernail across a part to see if it catches on something can identify issues pretty well.
In conclusion it's a big bore two stroke. As long as you don't seize it or run it really hard they can go way longer than the smaller two strokes.
That said, you could just run it. On a two stroke it might just cause a tiny amount of excess wear.
A lot of times surface discoloration is just visual. I use the measuring devices, but sometimes simply running your fingernail across a part to see if it catches on something can identify issues pretty well.
In conclusion it's a big bore two stroke. As long as you don't seize it or run it really hard they can go way longer than the smaller two strokes.
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The day the motor mounts came loose, I noticed an increase in vibes immediately. The frame made a weird hum and gave it away almost instantly.
Before then, no noticeable difference. I have never had an issue riding it all day. -BIG DAN
Didn't you have the crank rebuilt?
Yeah, I had the bottom rod bearing/pin replaced when my play reached 0.001"
Why do you ask about the vibes and crank?
-BIG DAN
When they vibrate more than usual it's a sign that the crank or rod may be twisted or out of balance. I really like your wr. It's a really really sweet bike.
so I want to see you enjoy it for a very long time 