I just thought of something while replying to the hondas answer to yamaha post. I know that the first 250R ATC's were the engine from their dirt bike. Was the dirtbikes engine counterbalanced from the start? Or did Honda add that for the ATC frame? Any thoughts?

i think the added them when they made they liqiud cooled in 85. not positve on that

Only the 81 and 82 R's used the Elsinore engine the 83 and 84 did not. I just think it funny cause if they did that means you could probably counterbalance a larger engine eg. CR500 in a TRXR frame...

you are right the first atc were the cr engine but then they changed the engine. are you asking if you could just use a atc counterbalance on a cr500. if you are i do not think it could be done very simply (you could not just bolt it on).

to install a counterbalencer, you need to get all new cases made, not a really easy thing to do unless you are honda. hey psi425, i bet your r just simply rips! i read the review in atv sport and it sounds scary fast!

So what you are saying is that Honda redisigned the case to give it a counterbalancer? If so then you could do that to a CR500 engine too. That would be a cool project if anyone tried it. That would almost be worth it if you spent 20,000 dollars on the project like the guy did in an issue of Dirt Wheels. I can't remember if this was a modification he did or not but if I were to spend 20,000 dollars on it I probably would!