'86 CR250 Engine help

[ASP1227]

Ok guys, I've got a '86 CR250 I'm rebuilding from pretty much scratch. I've got what I believe is now a complete engine, just need to rebuild it. It was missing a head. Anyways I looked in the manual at the powervalve and am a little overwhelmed about what exactly to do here. Does anyone know how to really work on one these powervalves. It looks more complex than the entire engine. I haven't tore into it yet, just wanted to get some advice on how people usually go about working on it. The bike also does not seem to shift, or at least shift right. The shifter moves in and out and the linkage seems out of wack. I know I'll be splitting the cases, this will be a first, and will probably go through the transmission. This is my third smoker, first Honda smoker, and also first with some type of powervalve. Any advice would be extremely appreciated!

[Sloryd66]

Holy guacamole.......take a look here on the microfiche for the breakdown of the gazillion parts to at least have an idea of how it all goes together.

http://www.hondapartshouse.com/oemparts/a/hon/506bdbc2f870023420a27ada/exhaust-valve

Here's a snapshot of how it works to also get an idea....hope this info helps.

 

[ASP1227]

It seems pretty simple in concept, it's just there are so many little parts, clips, washers, springs, and other stuff. Putting it back together is what I'm worried about. Right now the cylinder is off the bike, and the valves are closed. One moves in and out, the other move about an 1/8 of an inch but won't move much more than that.

[Sloryd66]

One is probably gummed up with carbon and why it's not moving as much as the other......if you follow the link I posted for the parts microfiche, hopefully it will help keep track of all the tid-bits and their order of assembly ?

Edited July 19, 2017 by Sloryd66

[ASP1227]

Yeah I saw that, it will definitely help. I like to look at diagrams with just the parts. The Honda manual shows a bunch of other stuff intermingled with the powervalve and it was pretty confusing. Your link is a lot more clear. The parts do look pretty dirty. One thing I noticed was that the cylinder was missing the two bolts that hold the valve guides in place, but I already ordered those, 6x14mm flange bolt I believe.

[Sloryd66]

Oven cleaner on the power valves once you get them out should take care of any carbon buildup. Everything else I use brake-kleen on to degrease and clean. Then some molylube or something suitable during reassembly to lubricate everything again. Best of luck getting it back together man.?

[ASP1227]

Thank you sir. I appreciate your help. I'm excited to get this thing up and running. I've always liked the 80's Hondas. This is my second Honda bike, the first being my '83 xr200r. I got this thing for dirt cheap mainly because it was in dire shape and needed lots of love. I'm excited to get it running, though it probably won't be for some a while. I'm hoping by late fall it'll be ready to run once more.

[Sloryd66]

I absolutely love tinkering and working on bikes....I've rebuilt more than I care to remember in my lifetime. Nothing more satisfying than seeing the end result of taking something that looks like it should be buried and resurrecting new life into it. I've done some that you'd swear couldn't possibly be the same machine ?

[ASP1227]

That's awesome! This will be my second ressurection, the first being my old '78 yz400. That thing looked pretty rough when I got it but now it's in great running shape, it just needs to look the part. It was a lot simpler that this Honda, but I'm not too worried about it.