Tranny Gear Modifications

[ghak99]

I have posted this before, but never got anything usefull out of it. Does anyone know what this mod is on the 250x or what needs to be done. I am going to be swapping cases so while the bottom end is apart I wanted to go ahead and do it. I believe one of the gears in the 250x bottom end is weak and you can replace it with a better gear out of some other motor, but that is all I know. Could anyone point me in the right direction?

[Rich250RRacer]

I believe it's second gear on both the main and counter shafts. It's been quite awhile since I've done trans work on one of these, but I have done three or four. You can replace the older gears with the 91-92 parts, these are revised and strengthened.

[ghak99]

Thanks, that is just the information I was looking for. I 'll wait to see if anyone else posts up before ordering the gears.

[MR FDO]

It's 3'rd gear ( countershaft ) and the left shift fork . 1988 - 1992 250x's have the improved gear & shiftfork . 1987 250x's were the only ones with the weak gear & fork . The new fork has had the wear pad moved from the tips to the inside for more rigidity and the new gear has 3 large engagement slots instead of 6 small ones. You can take some of the end play out of the countershaft by adding shims between the left case and the countershaft . I usually try to end up with .010-.020 end play. This will help it shift a more positive feel. Good Luck, MIKE

my friends 1987's third gear went out on his 250x

[ghak99]

Thanks for clearing that up MR FDO