Ignition Timing Issue
  • jjohnson598
    Posts: 4
    Joined: Tue Jul 10, 2018 4:13 pm

    Ignition Timing Issue

    by jjohnson598 » Tue Jul 10, 2018 4:20 pm

    Hey guys, so I'm just getting done rebuilding a blown up 2007 Crf250r. The bike has a new Crank, Piston, Valves, Cam, Cam Chain, etc. The issue I'm having is that the punch marks on the flywheel are not lining up with the cut out in the threads. With this being said, on the right side the arrow is lined up dead nuts with the punch on the gear and the cam marks are flat with the head. This is telling me the valve timing is right on, but the ignition timing is out of wack. With the bike at TDC the cutout in the threads is about 1/4 inch to the right of the right punch mark on the flywheel. The shear pin in the crank shaft is still good. Is there anyway the flywheel itself could be defective. Defective as in the punch marks somehow moved? Thanks in advance.
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    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Ignition Timing Issue

    by JimDirt » Tue Jul 10, 2018 8:02 pm

    Welcome to the site !! \:D/

    I think what your looking at is confusing you , what you need to worry about is when the ignition cover is on and everything is a TDC the "F" mark on the flywheel should line up with the mark on the ignition cover in the small round plug hole , if that is on and your cam marks are like this - - , and the triangle and dot are aligned on the clutch side in the large round plug hole all at the same time , you should be in time

    I can post pictures from the Factory Honda Service Manual if you need , but what i said to look at should give you a idea if something is off or not
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • jjohnson598
    Posts: 4
    Joined: Tue Jul 10, 2018 4:13 pm

    Re: Ignition Timing Issue

    by jjohnson598 » Wed Jul 11, 2018 11:21 am

    Hey thanks for the reply Jim. I posted some pics for you to look at, and as far as the F mark on the flywheel is concerned I'm not sure how I can see that through the left side hole. In the second picture you can see how the left cam mark is slightly up and the right is slightly down and when i mean slight i mean slight, if i line the cam marks up exactly even with the top of the head then the cut in the threads will be about 1/8 of an inch to the right of the right punch mark on the flywheel.

    Image
    Image
    Image

    Thanks in advance!
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    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Ignition Timing Issue

    by JimDirt » Wed Jul 11, 2018 12:31 pm

    You can just mark the F with a Sharpie but do it on the side which would face the hole , that way you can see it clearly , but its the second notch (if going clockwise) , is the Tensioner in a set when your noticing this ?? , it should align with a new chain , so not sure why it would be off , you can do a "test , by moving the chain 1 tooth and seeing if it makes a difference , but i would suspect it will be much farther off than it is now , did you try rotating the engine 1 or 2 revolutions by hand using the kick starter and your hand (with the spark plug out for ease of turning) and see if its still out ?? , hopefully after rotating the engine a few times , it will show it correctly .... report back with findings .... :-k 8-[
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • jjohnson598
    Posts: 4
    Joined: Tue Jul 10, 2018 4:13 pm

    Re: Ignition Timing Issue

    by jjohnson598 » Wed Jul 11, 2018 1:02 pm

    Yes the tensioner is indeed in. I think I may have found my issue though. When placing the tensioner in I thought I was a wise rear outsmarting the engineering and just bolted the tensioner in without getting a screwdriver and relieving the tension. From what ive been hearing if you dont back the tension off when bolting it the head it will cause the tensioner to bind causing it to push the cam chain too tight resulting in a timing issue. Thanks :-k
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    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Ignition Timing Issue

    by JimDirt » Wed Jul 11, 2018 1:36 pm

    Let us know if that did fix the issue , or if its still off slightly , the info might help others ... ;)
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • jjohnson598
    Posts: 4
    Joined: Tue Jul 10, 2018 4:13 pm

    Re: Ignition Timing Issue

    by jjohnson598 » Wed Jul 11, 2018 4:47 pm

    Well Jim I appreciate all your help, it did end up being that chain tensioner. I'm a bone head and put the tensioner in without retracting the tension the first time and it was pushing my cam chain too tight. Shes fired up and running now. Thanks again Jim! :) :D
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Ignition Timing Issue

    by JimDirt » Wed Jul 11, 2018 6:11 pm

    No problem , glad to help , even though i didn't really help :-$

    But glad you got it working correctly ;)
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Tsmith196
    Posts: 1
    Joined: Wed Apr 15, 2020 4:29 pm

    Re: Ignition Timing Issue

    by Tsmith196 » Wed Apr 15, 2020 4:33 pm

    I have a 2007 Honda crf 250r and my ignition timing marks are off too. Did you ever find a fix for this
    This would make sense on why I always had a extremely hard Time starting this bike since brand new

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