85 XC 500 Resto.

so today i was able to get inside to take measurments, by my calculations this this is 490cc. The piston is stamped 83.42 wich is the bore.
the stroke i measured with callipers at very close to 75.10mm. All parts look excellent so i will clean up and re seal. Im not sure what to think about this bike. How did it become a 490cc bike. I think its an 86 xc 400 original. It also has a square headlight where most bikes this age have a round. I will get pics up tomorrow.

Acording to the 1986 400cc tech. sheet.
std bore = 82.5 mm
1st over = 83.0 mm
2nd over = 83.5 mm
3rd over = NA
Stroke = 74.0 mm
If it were a 500cc the std bore = 86.0 mm, and the stroke = 84.0 mm
Looks like its a 400 on it's final bore.

the cylinder walls are looking thin.

been doing some shopping on ebay and my right side radiator is smashed but holds water. My question is winner racing on ebay, they are selling L.H. and R.H. radiators and 7pc coolant hoses is this stuff worth buying? Looks like the stuff comes from china.

Is it smashed or just curved from being laid on it's side? Chinese stuff is junk, plus I hear that mounts brake off fairly easy. You would do better to find a good used set on ebay. I bought a nice used set with hoses awhile back for $20 plus ship. off ebay.

As far as the cyclinder goes you should be able to bolt on a 430 cyclinder and head later on down the road.

Ok most china stuff is junk but for a $108 for all that stuff seems to good to be good. Should I ride this bike? I don't ride much but always enjoy it when im out. I would have to drive 1-2 hours to ride it. Im looking for an enduro or dual sport with street tires. What kind of choices do I have? Something I can ride to work about 16-20 miles a day. 2 or 4 stroke.

jim its just curved in preety good.

The one on my 87 250 is curved and rubbing the frame, it still cools fine and can't really tell when the bike is together, just by looking at it. As long as the mounts are good and the radiator cover snaps up into the fuel tank, I would use it and use those resources some where else on the bike.

strip the motor, get the transfer ports matched to the cases and tidy up the transfers to match the base gasket. there is usually a lot of spare metal in these areas and matching every edge and tidying will increase the torque considerably and make the motor smooth and easier to ride. dont toucht the exhaust port!! it will turn into a very scary 125. trust me on this...

i see somewhere else the chinee rads broke the mounts but the units were good. if you buy them, just get a radiator joint to redo the mounts

I too have an 86 400. Although it does have a 430 jug and piston on it. I picked it up about 6 months ago and I have to tell ya it has kept all my other bikes in the garage. On the trails with the family it is comfy ALL day long and when out with just my teenaged boys it rips across the desert.

Nice lookin bike you got there, and sounds like it runs just as well.

I had some free time today in the shop watching football and working on the xc. here are some more tear down pics. the rear drum brakes do not work, I found only one spring inside holding tension on the shoes. I think there should be two. Any info to get these working would be great.

Yes there should be 2 springs

I have the chinese ones on my 400 and the mounts broke off through vibration.
I made heavier mounts and got them welded on , cost me $170 aud which is as much as a new set of radiators but no more problems.
The original husky ones are real tough and can be straightened in a press.
I have taken the nana [ bow ] out of 3 or 4 and have also made them square again with no leaks.
cheers

Im done with the tear down. It went very well. Im looking for something to ride, and this is going to be the bike, Im going to build the bike so I can ride it,
I decided I dont want a trailer queen. My plan is to upgrade this bike to my liking and i hope you guys will like what I do. stay tuned.

That's what my Husky is for too.

Hey 2-, down load the parts manual from this site and print it out and keep it in the shed. It will solve all those issues like what is supposed to go where, how long are the bolts for "this part" supposed to be?
Which side is the washer on??. i found it good for working out where i had stuffed up!! and what bolts i should have used.... will be well thumbed when you finish the job....

I too printed the manual out here and keep it in a binder in the garage. It does make EVERYTHING crystal clear. I am happy to hear you will be setting your bike up to your liking and riding it. You will find it to be a "do it all bike"