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Honda 400ex Timing

3K views 13 replies 5 participants last post by  SlammedRanger 
#1 ·
Hey everyone, Sorry If I put this somewhere wrong, IDK what im doing lol, I just need help. I'm new to this forum and I just have a quick question. I'm having a hard time trying to make sure my timing isn't off before I try and start this fourwheeler, I'm new to doing the timing on four wheelers, but I have done it on cars, if anyone can give me some tips that would be greatly appreciated! Thanks!
 
#4 ·
Here are the key points to timing the engine.
1. Remove the covers on the flywheel side of the engine.
2. Turn the 17mm bolt counterclock wise till you line up the |T in the small hole
3. Make sure your piston is at TDC through the spark plug hole
4. Put cam in with lobes facing downward and the cam gear has indexing marks to line up with the head surface if it has 3 indexing markes one should be pointed straight up
5. Adjust the timing chain one tooth at a time and leave all the slack at the back side so the tensioner can take it up
6. With the tensioner in place the lines should be exactly flush with the head on both sides.
7. Install valve cover with new metal gasket and adjust valves (always adjust valve anytime you remove the valve cover.
8. Turn it over by hand counterclock wise again a few full revolutions to be sure everything is clear and you have no binding anywhere.
9. Install the side covers and start her up.
Good luck! Very easy quad to time.
 
#6 ·
if all else fails ?, there is a sticky in the repair section by me, that goes into great detail on how to set, and adjust valves on all 4-stroke motors. I know not all motors are made the same as far as lay-out ?, but they ALL work the same way !..lol. have a look at the sticky, it may help you :).
 
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#9 · (Edited)
Also to set the valves after assembly and timing check:

The easiest way is to remove the spark plug, stick your finger over the plug hole and bump the starter until you feel the compression push on your finger Stop there, take a long screwdriver and stick it in the plug hole, take the timing caps off of the left case cover (stator) take you 17mm socket and pull bar and turn the engine COUNTER CLOCKWISE until the -T- mark is aligned with the index mark in the small hole. Hold the screwdriver while you are turning it over so 1. it doesn't bind and 2. so you can feel when the piston is at the top. This will be where you set the valve lash. You will set it to .004 intake and .005 exhaust. You want a tight drag on the feeler gauge too.
 
#11 ·
Alright update on the 400ex.... I got it running and I just wanted to say thanks to shadetree, TRX2fiveO and Slammed ranger. I really appreciate the help you guys gave me. Had a great weekend riding with family and friends, quad gave me no problems. I just wanted to thank you guys agian with all the help that you gave to me and other people when they have questions. Thanks again guys!
Cameron
 
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