[Kyleq]

How’s it going guys. I am in need of major help. Me and my buddy are rebuilding the top end on my quad and I decided to order all new oem parts for the inside including the valve guides. After knocking out the old ones (and breaking one of course) I realized the valve guides I ordered were too large. After going back to the diagram online it says that they are indeed oversized and the only option available. I’ve contacted numerous dealers and even Honda who have all told me the only part they can pull up for my quad are the oversized ones. I was wondering if anyone has ever replaced the valve guides on a trx250tm or has any insight on where I can find the standard valve guides. Thanks

 

[Jeepwm69]

@shadetree ran into this on a build a while back. If I recall correctly no one sells std size valve guides. They're all OS.

 

[Kyleq]

Thanks for the info. Hopefully @shadetree will have a solution.

 

[retro]

You'll have to buy a 5.5mm valve guide reamer, or take the head to someone who is equipped with a reamer to resize the new guides to spec. Honda does not sell standard bore valve guides.

 

[wheelsquad]

Yep exactly what @retro says. I recently just went through this with my 400AT. And honda's use of the term "oversize" is misleading. The new valve guides you actually get from Honda are the same size on the OD (though you have to heat the head and freeze the guide and still need to drive them in). And the bore is actually smaller ID than needed, which is what the reamer is for. A smaller ID bore is definitely not "oversize" by my book, but apparently it is for Honda.

 

[shadetree]

Thanks for the info. Hopefully @shadetree will have a solution.

answer: you will either have to buy another head ( new or used ), or, find a used broken head, remove the valve guides, and install them into your head. all valve guides from honda are sold as over sized. you can not buy new guides that are a simple press in.

 

[SamUK]

If it were me I'd take the advice above and equip myself with the necessary equipment to do the job in question. I hate having to rely on others to do a job I know I'm capable of myself.
It sounds a challenging job but all in all its actually quite straightforward, if you have the tools/machinery to hand.

Just to add... You can 'ream' by hand, do some research, it's not impossible

 

[retro]

Yep, as @SamUK said, you can buy a 5.5 MM reamer (with a pilot section on the end) for hand reaming those new valve guides for less than $25 USD on ebay. I'm gonna buy a couple of them to have on hand for loaners. I'll post again in this thread once they arrive.