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Old 06-10-08, 08:51 AM   #1
Ceebl
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Thumbs down Misfires and the like.

Right I recently took the wading outa my exhaust to se what it sounded like and then put it back in because it messed up the firing n made it stall n dirty n stuff!
now its put back together properly it still isnt perfect, i dont know now if its related to the exhaust or not!
occasionally itl go off a cylinder and be really crappy n i hav to rev the balls off it to get the cylinder back on, and when im cruising about at like 3krpm and i twist it hard it shudders n missfires before it picks up, u can see the rev counter goin nuts when this happens and at idle when the cylinder stops firing the counter generally goes to zero!!
im just hoping one of my carbs isnt ballsed up again as the bikes under warranty and all mechanical work has to b done by my dealer (usually free because they sold me a bike that has a few probs it seems)
:@
im considerin runnin it on higher octane petrol for a while to see if that makes a difference!
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Old 06-10-08, 09:30 AM   #2
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Default Re: Missfires and the like!

OK,

Could you please provide as much detail about the bike as possible (Year, modifications etc).

There are several things that could cause these sort of symptoms, but the clearer you are on what's been done to the bike, and how long it's been doing this the easier it is to give you good advice. So to kick off:

What year is the bike?
Has it ever run right?
Did you touch anything at all apart from the end can before it started missing?
Have you ridden in the rain / jet washed it about the time it started behaving badly?

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Old 06-10-08, 09:36 AM   #3
Ceebl
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Default Re: Missfires and the like!

right
2001 sv 650 s
derestricted and had full engine balanced and plugs changed in last few thousand miles, the problems started when i took the wadding outa the exhaust
got better but not completely fixed when i put it back in
unless i havnt put it in right and its cloggin it up wud b my worry
its a beowulf can, not that that makes any difference
erm its been runnin dodgy for the last sorta 50miles since i did this, im doubtin its a wet or dirt as it seems too related to the exhaust timing! i may take the can apart again and neaten the wadding out or somethin!!!
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Old 06-10-08, 10:24 AM   #4
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Default Re: Missfires and the like!

Full engine balanced? How much did this rob you?

Have you got an air leak somewhere, it sounds as if it could be running lean.

Ahhh hold up... just read the bit about rev counter doing wierd stuff. You've either got the lead to the front coil loose, or a battery or earth lead loose.
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Old 06-10-08, 10:51 AM   #5
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Default Re: Missfires and the like!

Quote:
Originally Posted by yorkie_chris View Post
Full engine balanced? How much did this rob you?
I would be guessing he means carb balance..

I would 2nd what YC has said, look for loose battery terminals, loose coil leads and loose main relay contacts.

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Old 06-10-08, 11:22 AM   #6
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Default Re: Misfires and the like.

Because of this:

Quote:
Originally Posted by Ceebl View Post
u can see the rev counter goin nuts when this happens and at idle when the cylinder stops firing the counter generally goes to zero.
This is good advice:

Quote:
Originally Posted by jambo View Post
look for loose battery terminals, loose coil leads.
Your tacho being wierd strongly suggests an electrical/ignition problem is causing your poor running. If the problem were carburation the tacho wouldn't be affected.
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Old 06-10-08, 03:04 PM   #7
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Default Re: Misfires and the like.

Hi ceebl
Rode my bike and its good... very good
If you have a dodgy tacho and a cylinder misfire its most likely to be the feed to one of the coils, (as the tacho takes its reading from the sig. gen. Do you know which cylinder isn't firing?
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Old 06-10-08, 07:52 PM   #8
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Default Re: Misfires and the like.

No it doesn't. The tacho takes it reading from the front cylinder coil.
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Old 06-10-08, 09:39 PM   #9
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Default Re: Misfires and the like.

had the same prob. it was the wire (yellow and black) from front coil , left hand as your sat on bike if i remember correctly
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Old 06-10-08, 10:57 PM   #10
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Default Re: Misfires and the like.

Quote:
Originally Posted by yorkie_chris View Post
No it doesn't. The tacho takes it reading from the front cylinder coil.
Correct.
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