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Discussion Starter #1
Hello all,

I have noticed a problem with my 2003 F4s Evo3 lately. Whenever the engine is at idle, particularly after a long highway drive, it begins to make a "click" or sharp hiss every other second (sounds like when one releases air from the tires for a faction of a second). The engine has even stalled a couple of times. The bike has about 800 miles on it.
Has anyone experienced anything of the sort? I would like to know before I make my 100-mile pilgrimage to my nearest MV service shop. Thanks!
 

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The sound you describe (Phssstt?) I have heard a few time but not at idle, but when the electronic clutch operates the valves on #2 cylinder when gearing down reasonably hard. But your bike dose not have this?
 

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Discussion Starter #3
idle problems

agusta01 said:
The sound you describe (Phssstt?) I have heard a few time but not at idle, but when the electronic clutch operates the valves on #2 cylinder when gearing down reasonably hard. But your bike dose not have this?
Hey Agusta01,

This is a different sound, and it does only occur at idle. Almost like a very soft misfire. I think I am taking the bike to the shop, as it seems to be getting progressively worse. Now the engine idles a bit rough.

Thanks for your reply.
 

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Ok this sounds like a problem I have now, it started running rough only at idle though. When I rev it to 2500 there is no problem. It rides fine also with no missing. But at idle it's a little rough. When I hear the phsst sound as mentioned it runs ok for about a second.

Anyone got any ideas.
Thanks
Jonathan.
 

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Kinda sounds like a loose spark plug.
 

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+1, I had this occur on my pre evo f4 although not as bad. Once plugs replaced no problem.
It is indeed a miss that happens every now and then at idle, I found only happened when she was warm.

Replace\check your spark plugs - if they look fine then check the gap and then check leads with a multimeter for amounts of resistance.
 

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Your bike is 750 EVO 3.You do not have EBS relay . Change spark plugs first. Then I would change a chip in your ECU.
Haha sorry guys I butted in on this thread my f4 1000s does have a ebs relay and I was talking about mine. But I will change the plugs as you all suggest just strange it runs perfectly all the way to redline, just not at idle.

Thanks
Jonathan
 

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Same thing happens to my Brute 750, so for the first thing - determine which cylinder has a problem using vacuum synchronization tubes.
If it occurs on 1st, 3rd or 4th cylinder then certainly isn't EBS relay.

After determination cylinder, first thing you can do is to substitute ignition coil from any other cylinder. If now error occurs on that other cylinder, then you have a bad ignition coil (my case), if not do the same "test" with spark plug.

That's all for now ... give us some feedback.
 

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If this were my bike,

I'd take the tank and airbox off and have a look at the velocity stacks..in particular the rubbers which mount to the intakes for 1) security of fitting 2 ) splits

I'd also have a look see at the airfilter sealing tape to make sure it isn't leaking while I'm there..

You can also eyeball the movement of the throttle butterflys and how far open they are at tickover..Have a look in the manual. There is also a setting for opening with the little toggle lever on the handlebar rt side.

As a matter of course I would pull the plugs and change them..but also have a look at the plugs for combustion conditions...

If there is an air leak you may get the " Chitty, Chitty, Bang bangs" ..weak running and potentially detonation and a holed piston.

joe
 
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