20 Most Recent 1990 Honda XR 250 R Questions & Answers

head warped

No ignition. Bad key switch? No 12v getting to ignition. Do u know how to use multimeter ?

i would agree that it is a float problem all the signs of flooding after running a while.

The engine needs a rebuild , cant say how much will need repair until it is dis assembled.
It may need rings and valve seals.
but may also need oversize piston and rebore, if the existing ones are out of spec or scored and damaged.
It would be wise to also fit a cam chain while it is apart.
Some of the early XRs had problems with cracking heads and there are some speciallist companies like Ballards(australia) that may help for advice and the bits you may need.
They will sell 280cc kits and do any head repair work, including extra cooling fins welded to the head to turn it back into a good reliable bike.
If your in another country i'm sure there will be local specialists.

Did you ever done Decarb for your Motor Cycle ? It is recommended to do a Decarbonisation of Cylinder Head and Replace the liner every 30000 - 40000 Kms .
Black Smoke Can be Because of
1. Damaged Cylinder Liner 2. Dirty Cylinder Head 3. improper Combustion 4. Fuel problems 5. Fuel Pump / Carburetter Problems
need Physical Examination Foe a definite Solution

Please Rate my answer and Support me

Remove the cylinder head cover then tighten the four head bolts holding the head and cylinder to the gearbox. Hopefully you will not need to find and install a new cylinder gasket.

If you are getting gas than you have an air leak somewhere between your carb and the head. When the bike is ideling take a can of wd-40 spray slowly around every possable connection. ( rubber boot & where it bolts to the head ) When it sucks in air and wd-40 it will speed up and reveal the air leak. The boot itself could have a crack in it.

make sure theres no **** on the bottom of the gas tank blocking the intake to the carb.

Go to http://www.thumpertalk.com/topic/576969-1979-honda-xr80-wiring/

depends if your doing a lot of short outings etc ! ? if the oil is black then change it , do 100km after oil change and check condition ! mite take a few oil changes to get clean unless your up to stripping the engine and clean everything !? if using for competition then its different again , change after each meeting as harder work out and need to keep quality of oil to max ! also the piston and rings are changed after every meeting , try and get the xr manuel as its got the periods of replacements etc !

check carb is clean and settings , check timing !