Need 87 cr250 set-up tips

[reknelb]

I picked up an old cr250 from a friend, and was hoping to do some hare scrambles with it next year. I've ridden the bike ocassionaly over the past 2 years and it runs pretty good. It needs to be stiffened up in the suspension dept. which I'm in the process of doing. After that I want to do a top-end rebuild over the winter. I figured while I was in there I could do some other things to make it more suitable for trail/hare scrambles. My friend recieved the bike in trade for doing some head work and was told it had the ports matched, and a 1mm over wiseco (confirmed). It also has a pro circuit pipe, and one of those goofy roost boosts. I'm not really sure on the porting until I remove the cylinder and have a look, and even then I'm not much of a 2stroke guy so I wont really know what I'm looking at. I know it has a huge rear sprocket too. Tops out at around 60? How much top-end/speed will I need for hare scrambles?

My main questions are, do the flywheel weights really work? And how much top end do you lose when you have one. How much does a couple golf ball size dents in the pipe effect the power?

I'm planning on replacing the pipe but am curious to see If i can feel the difference. Also, any suggestions on brands of pipes, reeds, pistons,etc. (hopefully from someone who has ran this bike before)

 

[Rider 007]

A FWW will work very well on that bike in the woods. You don't lose any top end, you just change how quickly the engine gains and loses revs. It helps keep the rear wheel from breaking loose as easily, keeping you hooked up and in control. I recommend the heaviest one one you can find for it.

I don't think the dents you mention will noticeably affect the power, but it depends on where they are. We had good luck with a PC pipe for overall power.

The stock forks were very good, even off road. I can't remember if the 87 had a hard anodized shock body, so it should be serviced and checked ASAP. If the body is belled out, it will need to be replaced. Have it revalved while you're in there, as the stock action was only so-so.

Is the cylinder sleeved or bored and replated? I believe the stock cylinder was nicasil plated and didn't list overbores.

Boyesen reeds (old fiberglass two-stage) worked well and were durable.

Good sprockets and an o-ring chain are a plus.

I'd stay with OEM stuff as much as possible, as it's high quality and never gave us any trouble.

:ride:

 

[reknelb]

Thanks for the info. The shock is in good shape. I believe the forks and shock were re-done by race tech for one of the previous owners, just needs to be re-sprung.