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Bad idle after rebuild, Timing?

Old 09-29-2013, 08:04 PM
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Bad idle after rebuild, Timing?

Hope your guys' riding weather is better than Washington's

I just got finished rebuilding a neglected cooling system, and had the valves/shims checked by a dealership while the bike was stripped down.
The carbs were off for about 6 days and were partially drained of fuel.

The bike ran fine, and idled at about 1500 rpm (adjusted to be high) before the rebuild. Now it starts up fine. It runs on choke or while gas is given, but will die without either at about 800 rpm. There is a notable mechanical click sound that occurs every few seconds when the choke is off. The bike dies right after one of these click sounds.

I am curious if the dealership screwed up the timing? I don't know what bad timing sounds like, but a few posts talk about valve clicking and whatnot.
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Old 09-29-2013, 09:43 PM
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Have you tried adjusting the idle after it warms up and were the carbs synced after they were out back on?
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Old 09-30-2013, 04:37 AM
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It's supposed to idle at 1150-1200 rpm. At 800 your oil pump might not supply enough pressure. The clack is likely a carb slide slamming shut.
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Old 09-30-2013, 05:31 AM
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If they actually had to shim valves, it is possible that timing screwed up... you'd hope that them being a shop and all they wouldn't but it's possible. You more likely need to sync the carbs, though. 800rpm's is low and if you had them off to fix the cooling, they might be out of adjustment. I'd start with the carbs and go from there.
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Old 09-30-2013, 11:38 AM
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Ok, I tried adjusting the idle this morning and now it wont die during start up but when its warmed up it idles at 2K!!! I think my bike has delusional fantasies about being in MotoGP.

So carb sync then. Can anyone explain why one is needed? When I took the carbs off I didn't touch any screws or bolts on the thing. I avoid carburetors like they are the plague.
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Old 09-30-2013, 12:23 PM
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Before you begin syncing your carbs, try to lower your idle to about 1200rpms as mentioned above.

The carbs need to be synced since as the word says, the are syncronized to open and close together. The only thing that keeps them synced is a little spring pressured screw on the left side. Many times, just manipulating the carbs from and onto the bike, may wack them out of sync, thus, syncronizing them is necessary.

Unfortunately for you, this is an operation that needs to be done. Once you've syned them, you may need to adjust idle speed again. Depending on year, idle speed will vary between 1100 and 1200rpm's.
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Old 09-30-2013, 12:54 PM
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Your idle needs to be adjusted when the bike is WARM, not cold.

As stated, sync the carbs.

I had the same issue with the "mechanical clink sound" then the bike would die. I pulled both valve covers and ran the bike cold till it did it, I found it to be over fueling of the front cylinder causing a missfire when the miss occured it caused slack in the camchain, then the rear would fire and it would snap back to tension (I.E. not good for the chain, tensioners, gears ect.)

Synced carbs, performed a tune up, and it hasnt happened since.
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