20 Most Recent 1987 Honda XR 250 R Questions & Answers

RH side engine case, Remove clutch assy, and oil pump housing.Remove (1) 10mm Bolt securing lower end of tensioner.

Might be a good idea to check your timing first and then if the timing is ok try removing your exaust pipe and running it for a few minutes without the exaust system installed. I have encountered a couple of bikes where the exaust system has carboned up and will not allow the engine to breathe especially at hiogher rpms. A day in the gunk tank for the exaust pipe did the trick and the bike ran like new. (Gunk will remove all the paint too)

The compression is low. This indicates bad piston rings. The cylinder may look okay but chances are the cylinder wall has low spots. I suggest you have the shop bore the cylinder and install a first oversize piston and rings. Since the head is already off, I would re-seat the valves and install new valve guide seals. With proper compression the bike will be noticeably stronger.

Backfiring through the carb isn't a timing issue unless you're firing at BDC (180 degrees out).
or have bad/missing/cracked piston rings / hole in the piston.
I mean, correct me if I am wrong, but that thing IS a 2 stroke, right?

This can be one of five things,

1: The coil is bad
2: The cdi is bad
3: The stator
4: The stator pickup
5: Bad plug

Use a spark plug tester on the coil to test for current, if it doesn't have current to the plug work your way backwards toward the stator, testing each item for current in and out.

Needs piston and rings.

check that the pads are freein the calipar and that the calipar pistons are free, they may be corroded or just need cleaned up and new seals fitted

here you go

http://www.thumpertalk.com/forum/archive/index.php/t-594992.html

http://www.4strokes.com/forums/topic.asp?ARCHIVE=true&TOPIC_ID=19536

you can't adj. it the cam chain adj. is spring loaded. if your chain is lose there would be three things i would replace, the cam chain. the followers and the adj.
Given the age it wouldn't hurt please it will give a chance to look over the vavle trian.
Mark
C.C. Motorsports

This is engine oil burning ,I bet it smells oily. The valve guide seals under the rocker cover are worn ,or the piston rings are worn and poss the bore on such a old bike this is common. If you have little money just keep going ,the spark plug will eventually fail, Or you will need to restore your engine with a strip and rebuild.New seals, rings and check bore piston tolerance .

this is where the spark plug screws buddy

if the bike runs good and is in decent shape it is well worth 900 bucks take it for a ride and test brakes and clutch

first you need to get a fly wheel puller. then remove the nut in the middle of fly wheel,insert fly wheel puller,reverce thread,tighten pin and it will pop off fly wheel.when you put it back on remember to line up "woodruff key",its a little notch on fly wheel whitch lines up with a ridge on cam shaft. if you cant fix your problem and you have spark its probobly your coil and condencer.

TDC on intake stroke

Just make sure the resistors are securely attached to the bike. Just supporting them with the connecting wires isn't enough.

When engine is cold. Exhaust clearance is .003 and intake clearence is .002.
Hope this helps get you back on the road.

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The ignition timing on your bike is CDI based and cannot be changed. Absolutely no way to change it. Valve timing is a different matter and involves static timing marks on the OHC gear. If the bike runs at all then the valve timing is set properly as is.

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