How do i tighten my cam chain on my 03 xr 250

WE INSPECT IT WITH MARK1, EYEBALLS (A MIL JOKE)
SCAN IT YET, SEE CAM, ERRORS. >> USING REAL SCAN TOOL.?
NO ENGINE TOLD 2.4l IS CAM BELT
VIN DIGIT #8 IS ENGINE CODE, NOT TOLD AND IS A PURE ENGINE QUESTION.
OR THE 3.7l LIKE MINE V6, ?
IF A CHAIN GOES BAD IT MAKES HUGE RACKET.
THAT MEANS NEVER RUN it LIKE THAT. EVER.
Both engines are interference, so driving them with bad cam drive
has huge risk of engine damage $3000 + bills, parts./labor

not told at all why? is engine acting odd. or makes nasty sounds.
or CEL lamp; on ? or other cluster errors glowing.
or what? what's up doc?

top evidences is lost power or engine destruction.
huge racket (noise max)
for the belt drive snapped, it makes noise only on destructiong
head valves hit piston, wrecked
why not get it serviced and ask the person live for advice.
ask the tech in a shop.
say check it out.

You must remove the entire tensioner and leave it out while you swap out the sprocket. Set it to it most retracted position and then install. Adjust it after it is installed. Make sure you have some slack or you will break the chain.

Both the 1985 honda xr250r and xr350 look loke they have self adjusting cam chain tensioners. You may have a broken tensioner or tensioner guide. With the age of the bike you may need a new cam chain. There is nothing to adjust so you need to just figure out if the chain is stretched , if a guide is broken, or if the tensioning mechanism is malfunctioning.

the thing is, you cannot tighten the chain, it needs to be replaced.. but what you want to do is make sure the cam chain tentioner is working properly mabye it is stuck open.. let me know how you make out

the ignition timing is electronic, you dont adjust it.
if you mean valve timing.. if it is out of time then you probably need a cam chain and tensioner,

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

If you need to remove the cylinder head, here's how. To remove the cam chain, you've got to also remove the left crankcase cover and flywheel.

First, you need to turn the engine over until the piston is at top dead center (TDC) of the compression stroke. Begin by removing the two round covers from the left side of the crankcase cover. Also remove the four tappet hole covers from the cylinder head cover. Turn the engine (in the normal direction of rotation) and watch the intake valves open - and close, then see that the exhaust valves open, then close. Now align the 'T' on the flywheel with the notch in the inspection hole. With all of the valves closed, the engine is at TDC of the compression stroke. Do not begin removal of the cylinder head cover until this is done - to avoid damage to the cover.

With the cylinder head cover removed, you will find two bolts attaching the cam chain sprocket to the camshaft. Turn the engine until you can get a 10mm socet onto the heads of the bolts and remove them. The sprocket will come loose and slide down onto the camshaft, enabling you to remove it an the camshaft.

Upon reassembly, set the cam timing by first setting the engine at TDC. Then, align the two marks on the cam sprocket with the gasket surface on the cylinder head. With the engine at TDC and the marks lined up, the cam timing is properly set.

Before calling the job done, make sure to adjust the tappet clearances to .002" on the intake and .003" on the exhaust valves.

check the timing marks on the crank and cam make sure they are alligned at tdc