First 4 Stroke, is timing off?

I am new to this forum so here it goes.  I have been a two stoke guy my whole life but came across a deal last summer on a 04 kx 250f that I couldnt pass up.  According to the seller the top end was rebuilt and stage two hot cams were installed.  So I didnt really get to ride the bike very much last summer and wanted to check the valves to make sure they are in spec before the riding season this year.  The bike did run but the carb needed cleaned so I just finished doing that.  Ok so to my question that hopefully someone can help me with, when I removed the I guess valve cover it looked to me like the timing marks were off on the exhaust side of the engine.  I watch a few youtube videos and they said the dots should be at 12 and 3 on the intake side and 12 and 9 on the exhaust side but they looked off to me like a tooth off on the exhaust side.  I thought the side dots are suppost to align with the case.  Would it still run if it was a tooth off.  Can anyone verfiy that they are off?  Also would I have to correct that before checking valve clearances?  Thanks for everyones help.  I have attached a photos of it.



I'm not familiar with the bike, but it looks 1/2 tooth off to me. Could be chain wear or the hot cams? The bike should still run and you should have no issues checking the valves. If you have to pull the cams to adjust the valves, I try rotating 1 tooth forward and see if it looks closer.

Finally you might try the model specific forum for someone more familiar.


If it's like my 450, it should have 29 links from the first EX dot to the last IN dot. I counted 28 links in your photo (and it does look off), so yes you are off by a tooth. You''ll have to remove the cam caps and the tensioner to adjust the camshaft position. Make sure the piston is at TDC and adjust away!

Edited by CincoBoy

A workshop manual would give you the answer

One of the cams is off a tooth, depending if your Piston is at TDC or not , if the piston is at TDC then the exhaust is off.


the mark may go a little past the bottom of the head as the chain could be a bit stretched.    

Thank you for all of the replies.  I did find a manual for the bike online so I am going to consult that to see what they have to say about the matter.  I did suspect that it was off a tooth as it just didnt look right to me like the intake side.  If it is off a tooth is this something I need to adjust or would it be fine running it the way it is?  If i do adjust can i just undo the chain tensioner and move the cam or do i need to undo the cam holddowns up top to turn it, I just want to make sure I get an accurate reading with the fuller gauges.

Having it off by one tooth can at the least rob you of some power and can potentially slap the piston, which, if left unchecked, could score the piston, bend the valve, or really mess up the top end. These machines have fairly tight tolerances and can get messed up if out of spec too much.


Whenever I've done head work, I usually had the cam caps off anyway, so I'm not sure if the camshafts can be adjusted by removing the tensioner. Give that a try first and if it doesn't work, just follow the manual very closely about removing and installing camshafts. You should be good to go.

That is what I was worried about happening.  So I took my lunch break from work and checked out the manual and found this out.  I cut and pasted the part about alligning the timing marks.  The exhaust cam in the photo seems to be turned like mine but there dots allign with the top of the head where mine seems a little off.  It says a 28 count between the two alignment marks and mine if you look a the photos from before has the 28 I believe, but it just doesnt look right to me :rant: Thanks for the help.

Cam 1.PNG

Cam 2.PNG

Yours does look correct as per the manual, maybe its the angle of the photo that makes it look out.   

It just worried me that my dot was not alligned with the head.  Maybe the punchmark on the cam gear is a little off.

I have never seen them line up perfectly, always a mm or so off and if the chain stretches then it also changes a bit. 

Ok I am going to go with that the timing is set correctly and check the clearances and go from there.

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