Jump to content
Sign in to follow this  

1985 CR80R Build

Recommended Posts

Hello, picked up this cr for cheap last friday. Doing a budget build for a friend, figured I would document my build as I complete it. Remember this bike is not being restored, rather just a good cleaning/check up. Here is a picture of the bike when I picked it up:

1402435125543.jpg

Share this post


Link to post
Share on other sites

So me and a few buddies stripped the bike down to the frame. A parts list was put together, so far we need:

bars

Levers

Forks

Gaskets

Pegs

Cables

The list will probably grow! Oh and I sandblasted and painted the frame and subframe yesterday.

1402448009977.jpg

1402448034348.jpg

1402448045219.jpg

Share this post


Link to post
Share on other sites

Tore into the motor today, noticed a few things that may worry me. Very light scoring, and I almost feel like some moron took a dremel to the ports throughout its life. Piston looks like its somewhat new, will probably just use it. Put my subframe on, I think the colors look ok! Alot to do!

1402499601135.jpg

1402499615398.jpg

1402499627790.jpg

1402499637355.jpg

Share this post


Link to post
Share on other sites

Wow had a 85 cr80 the last year of the atac it was really fast honda was tired of getting beat by the kx the cylinder is not plated can be bored over. Had a 84 cr60 then cr80 then 86 cr125 i was allergic to green then All my friends had kx's or yz's.

Share this post


Link to post
Share on other sites

Wow had a 85 cr80 the last year of the atac it was really fast honda was tired of getting beat by the kx the cylinder is not plated can be bored over. Had a 84 cr60 then cr80 then 86 cr125 i was allergic to green then All my friends had kx's or yz's.

One issue I'm going to have is with the exhaust manifold. There is a little gear that slides into the cylinder that actuates the little valve in the manifold? How does it line up to be timed correctly?

Share this post


Link to post
Share on other sites

I don't remember is there any marks to line up? It is supposed to be open on the low end to increase header pipe volume for better power. The close on the mid and supposed to improve the top end power lots of tuners said it didn't work because it had no effect on changing the exhaust port height / volume. It was based on if the exhaust pipe volume was increased it would increase bottom end.

The valve does not open n close very far pro circuit and dg used to sale pipes that would change the exhaust flange and do away with the atac chamber.

Share this post


Link to post
Share on other sites

I don't remember is there any marks to line up? It is supposed to be open on the low end to increase header pipe volume for better power. The close on the mid and supposed to improve the top end power lots of tuners said it didn't work because it had no effect on changing the exhaust port height / volume. It was based on if the exhaust pipe volume was increased it would increase bottom end.

The valve does not open n close very far pro circuit and dg used to sale pipes that would change the exhaust flange and do away with the atac chamber.

Thats great info! Im assuming it acts as a weak powervalve, but I think ill take it apart and clean it all as there is a lot of carbon built up.

Share this post


Link to post
Share on other sites

Yea it is a weak power valve if I remember now it should work like the usual power valve setup in the right engine case. There is a rod that fits into the cylinder area that has teeth on it since the arm moves very little I think the arm the teeth on the end line up with the gear on the atac in the open position and as it moves closes the valve. I think there was also a spring that helped pushed the rod closed in the cylinder too. Wow iI can remember it some lol

Share this post


Link to post
Share on other sites

Yea it is a weak power valve if I remember now it should work like the usual power valve setup in the right engine case. There is a rod that fits into the cylinder area that has teeth on it since the arm moves very little I think the arm the teeth on the end line up with the gear on the atac in the open position and as it moves closes the valve. I think there was also a spring that helped pushed the rod closed in the cylinder too. Wow iI can remember it some lol

Hopefully it goes together easy, ive never had good luck with power valves.

Share this post


Link to post
Share on other sites

Put the bottom end in the bike, and now it refuses to change gears. May sell the bike, dont want to split cases on this one.

Share this post


Link to post
Share on other sites

Hey just a thought , you probally need to pull the water pump cover and see how bad the corrosion is (a known issue with these bikes ) ! I to am restoring a 88 and it was repairable but I decided to replace it anyways but mine was still available new and now there made outa alluminum instead of magnesium at the cost of 200 bucks !!!

Share this post


Link to post
Share on other sites

Where'd you get that gold rim? Don't recall the 80 ever getting the gold rims like the bigger cr's.

Was on it when I bought it, I cant get the tranny to shift now so Im probably selling it unless I can figure it out

Share this post


Link to post
Share on other sites

Are you really in Pakistan? Also this was my first bike Ive ever owned. Saved up all summer for $525 after washing dishes at a pizza place in 1987. Ahhhhh,

good times.......good times.

Share this post


Link to post
Share on other sites

What you mean it won't shift? Did you pull the tranny apart? Most often the shift forks get bent or worn out causing the problem.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×