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Idle trouble after MCCT

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I posted a little while ago about hearing some rattling on deceleration on my DRZ400SM (11k miles). So I just installed a MCCT to hopefully remedy this, however now when starting it idles very strange (will die or climb/hold revs) and will backfire when revved. I took it back apart to check the timing and everything looks to be fine (picture attached).. any idea what's going on?

IMG_3698.JPG

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Your timing looks fine IF your piston is at top dead center. Changing to the MCCT should have no affect on idle, since you can match the cam chain tension to what you how your ACCT was. 

Did you follow the instructions carefully? Torque down the MCCT to the head, let your bike idle, then screw in the bolt until the cam chain chattering stops, and lock it in place. Your bike looks is still somewhat new so it makes sense that your MCCT could be backed out that far. I don't see why idle would be negatively affected with an MCCT set properly. You should recheck everything else you touched.

Here's some more reading on the subject.

 

Edited by HansLanda

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Yea I made sure the notch was visible in the view finder and cam lobes at the 10 and 2 position. I adjusted the MCCT in the same order you described as well.

Could it be a spark plug issue?

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18 minutes ago, Rekmore said:

Yea I made sure the notch was visible in the view finder and cam lobes at the 10 and 2 position. I adjusted the MCCT in the same order you described as well.

Could it be a spark plug issue?

It could be an issue with anything you touched, but only at only occurring at idle, I would think not. To reinstall the spark plug boot, carefully push it straight down and wiggle it a bit until it won't click down any further. Many recommend spraying some compressed air in there to remove any dirt (do this with the valve cover on), but I skipped this and it's been fine.

If your spark plug has not been inspected in 11,000 miles, then it could be a spark plug issue. The service interval for normal, non Iridium plugs is to replace every 7,500.

plugs.png

Edited by HansLanda

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Just went and took another look and it was definitely the vacuum hose connecting to the tank :facepalm:

Seems to be idling smooth now, thanks for the help guys.

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3 minutes ago, Rekmore said:

Just went and took another look and it was definitely the vacuum hose connecting to the tank :facepalm:

Seems to be idling smooth now, thanks for the help guys.

Haha nice. Always triple check your steps when doing work like this. You could FUBAR an engine real quick!

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If any of your friends have a vacuum petcock, you now know how to prank them.

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