Hi, I'm new to this forum, I've been riding my XT250 since 1991 and have only just heard about this roll pin modification. I remember back in the 90's some cam problems with the XTs and there was a heavier duty cam and rocker arm set which I bought and fitted. Never had any problems since. Now I'm worried that I need to do this crank mod! In May this year I probably gave it its hardest time ever on a 600 or 700 mile off road trip in Northern Spain with a few mates.

Hello and welcome to the forum. Same with the bike i bought. it has 8900 miles on it and no signs of wear or problems ever in the past without the update. I just did it so it was done for extra insurance the top end is getting plenty of oil.

I talked to a guy on facebook from England that bought a brand new XT250. rode it on the highway back and fourth to work and in no time the complete top end was worn out. He thought it was something he did wrong. after paying the dealer to fix the bike later on he said Yamaha came out with the service bulletin with the fix.

It's a easy fix to do if you decide to do it.

I think I'll nip out tomorrow and buy a pin. 

Can't say we ever had wear problems that related to lack of oil up top, only inferior quality material where sign of wear due to lack of oil didn't exist. I do wonder of restricting to the big end to give more up top might compromise the big end but maybe they get more than they need. I'll find a pic of my worn txt cam showing no sign of heat or lack of oil & one lobe is as new by memory so not an oil problem as run in the same bath so to speak.

Ok found it already back a couple of pages. My crappy ipad only shows the current page.Here's a link just to go with my thoughts above.
photos.app.goo.gl/A9k2LDfRK1gt9oBs6

Yes, it was the weak cam I was warned of back in the 90's which is why I fitted the newer stronger version. It does seem odd that Yamaha would recommend restricting oil flow to the bottom end.