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Old 02-02-10, 11:09 PM   #1
5hort5
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Default Slow rev decrease

Hi,

Bikes all back together but I have a small problem I'm hoping is a small problem. When letting the throttle off the grip snaps back fine but it's slow to drop the revs off below same around 2500 to idle? Also I'm having problems setting the idle, I get it correct for sitting in the drive but when out on the road it's way to high. if I set it lower though it slowly creeps down and the engine cuts out?

Any ideas?

(It's bound to be something I have (or haven't) done since I have the carbs off and in bits)
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Old 02-02-10, 11:20 PM   #2
beabert
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Default Re: Slow rev decrease

Adjust the idle to when its warm after a ride, and leave the choke on longer when on the drive so it warms up? Mine does the same thing if the idle is in too far.

You haven't messed with you pilot screw by any chance? i think they are sealed on the sv by default?
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Old 02-02-10, 11:30 PM   #3
5hort5
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Default Re: Slow rev decrease

nah, I left that well alone when I took the carbs to bits, it just doesn't feel right though, slow to drop revs? it didn't do that before.
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Old 02-02-10, 11:35 PM   #4
beabert
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Default Re: Slow rev decrease

Double checked all the rubbers are sealing correctly? and clamps fully tighted. Incidently what had you done? carb clean?

Like i said, mine does the exact same thing once i turn idle up it will drop in stages almost, from 5k then to 2k waits a while then settles back down.

Wait until someone more experienced replies
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Old 03-02-10, 07:42 AM   #5
Alpinestarhero
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Default Re: Slow rev decrease

Is it carburetted, your engine?

If so, your choke may be the problem here - it sounds like you had the same problem I had; corrosion in the choke plungers, causing them not to fully shut. I gave my bike to spannerman to get sorted for this, he said the front plunger was the culprit.

If your bike is FI...well, I'm not sure!

Other thingsn to check first are air leaks - are all the seals seated properly and sealing correctly?
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Old 03-02-10, 08:09 AM   #6
xXBADGERXx
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Default Re: Slow rev decrease

If it`s FI then it may be the links that control both throttle bodies , sometimes they get a bit dry or gunky and need a lube , I had to shut my throttle forwards rather than let the spring return it to it`s natural position . Lubed it and that sorted that problem out . This may be something similar for you .
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Old 03-02-10, 10:11 AM   #7
Taipan
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Default Re: Slow rev decrease

Classic air leak symptoms. Reseat the carbs and air box.
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Old 03-02-10, 11:13 AM   #8
Robert711
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Default Re: Slow rev decrease

Quote:
Originally Posted by Alpinestarhero View Post
If so, your choke may be the problem here - it sounds like you had the same problem I had; corrosion in the choke plungers, causing them not to fully shut. I gave my bike to spannerman to get sorted for this, he said the front plunger was the culprit.
+1 to that I have just had the exact same problem, just pulled the choke plungers out cleaned them with some degreaser and put them back bike now running like a dream.
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Old 03-02-10, 02:54 PM   #9
yorkie_chris
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Default Re: Slow rev decrease

Quote:
Originally Posted by beabert View Post
You haven't messed with you pilot screw by any chance? i think they are sealed on the sv by default?
The screws are exposed unless you are a septic.

First have a quick glance, see if the cam is actually returning fully.

If it is, then you may be running a little lean because of an air leak. Are you sure the airbox is connected and seated properly? Spray some WD around and see if the tickover sound changes.

Is there any backfiring or spitting back through the carbs?
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Old 03-02-10, 07:42 PM   #10
5hort5
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Default Re: Slow rev decrease

Ok - went out and sprayed some WD on the air box connector and the manifold? (bit between carb and engine) and no coughs or splutters.

When you say cams do you mean the bits the cables are attached to? If so then I'll double check that tomorrow when I have more light.

Many Thansk
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