Honda cr 250 1985 barrel

I'm not a expert on that but I don't think you canput a 87 cycylinder on the 85 model. I believe the have different exhaust power valve systems. But people have done some impressive things, so maybe someone who is more knowledge will chime in.

The 85 cr 250 was my first 250 and it was a stout bike. Tons of low end and midrange... My next 250 was the 88 cr250, and I hated that bike!!! I wanted a new 87 but they were all sold out...

Good luck with your bike...

This shop may be of help, if you need to restore the original

https://pjme.co.uk/

Nice 87 yz btw in your profile picture, i am currently restoring one check out my thread it may be of interest to you

No way you can use any cylinder other than the '85 unfortunately.

Honda's early power valve system was called ATAC ("Automatic Torque Amplification Chamber"). Honda debuted this with the 84 125/250. The device on the 125 was a can that was on the exhaust flange, but the 250 design was integrated into the cylinder and cases.

The hot tip on the '84 125 was to chunk the ATAC (the '85 125 was so much improved I didn't see it being removed when I was racing against them on my '84 KX125).

On the 250s Honda simply abandoned the design in 1986-- they went to the HPP system which was taken directly from the works bikes, and so, the '86-91 CR250 cylinders will interchange.

Honda stuck with ATAC on the 125s and made the gimmick work but even the '84 CR250 cylinders had a recall from Honda (the porting was so radical piston rings could hang up and the liner would flake off). So you really are stuck with the 85 cylinder.

And now you know why the '85 jug is difficult to find and expensive generally.

Whats wrong with the old one?

Barrels can easily be re-plated or lined for not a lot of money. Both cost around £150. I'd always choose re-plating over lining though.

Stevie

Well Mike.... When you put it like that.....

Hmmmm, seems like the rest of my reply didn't want to be posted! (It was late and I was on my phone, so my fat , podgy fingers may have deleted it...)

That can be repaired. But I would look for a replacment and way up the costs first.

Theres probably £40-£50 worth of welding (depending on the welder) and probably the same cost to clean it up and reshape it so it looks as it should, plus a few timeserts/helicoils as well.(usually around £7.00 each)

Either way, factor in the cost of re-plating it (approx £150) and, depending on how you are doing the rebuild, blasting and powdercoating/paint afterwards.

Stevie

So Stevie, roughly how much would a repair like this cost? A friend of mine who runs FullFloater.com recently gave one of these bikes to his younger brother and it has similar issues with the cylinder.

It all really depends on how much damage there is. To really get a good repair the barrel would need blasting first, to remove all the old paint and gunge. Then the welding, then all the re-shaping, tapping threads etc, then blasting again to "blend" the new and the old, then if wanted/needed, powder (or paint) along with rest of the the engine cases.

This one, would probably be £100-£120 ish, (can't really be sure with seeing them in person) plus re-plating the bore, any powder/paint and re-zinc plating or replacing the studs.

Stevie

Barkhard, Stevie is saying it cost less than 200 dollars to fix a trashed 85 cylinder before plating where he is from

Thanks Max and Stevie! When I talk to my buddy up in MI I'll pass the info along, I believe this bike is a long-term project of his kid brother's. I had an '86 and sure wish I still had it!

Pike170,

I have an '85 CR250 that I race / ride. I may have some spare parts that I can sell. I have a nice Pro Circuit pipe that I was keeping for a spare, front & rear hubs, front axle, nice set of forks, probably some other stuff. e-mail me @ hudweiser9@gmail.com with your needs. Sorry, don't have an extra cylinder to sell.