Honda 400ex Problem

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Oct 4, 2018 | 05:36 PM

Stephen01

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Weekend Warrior

Joined: Sep 2018

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Honda 400ex Problem

I just went into my Honda 400ex motor to do some top end work, then assembled everything back like it goes. Went to starter her up and it turned over but sounded like the valves were not opening or closing, so I took a look at the valves while I was turn the motor over in the valves were not moving at all. So I removed the cover and turned it over and the cam was moving But for some reason it is not open the valves at all. Does anybody have any and idea what could be wrong?

Oct 5, 2018 | 05:07 PM

Stephen01

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Weekend Warrior

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OK, I’ve narrowed the problem down a little bit but I’m still not sure exactly what’s wrong the motor turns over while the valves are off and the cam moves, but when I put the valve back on the cam does not move at all but the starter turns and sounds like a gear is not engaging or something could this be a problem?

Oct 6, 2018 | 07:43 AM

merryman

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Joined: Oct 2013

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From: Lancaster England

Never worked on a 400EX but looks like a similar set up to the 300s, so single overhead cam. You must not have got the cam chain on the crankshaft sprocket, so you will have to take the top sprocket and adjuster off, and get the chain back onto the lower sprocket. You may need to take the chain guides and/or clutch cover off to do this.