Increased backfire/misfire
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Increased backfire/misfire
Hey guys, so recently went thought and changed out my OEM auto CCT's to Krieger Manual CCT's following this guide:
www.vtr1000.org • View topic - Manual Cam Chain Tensioner Installation Guide (MCCT's)
Chain didnt jump any sprockets and i adjusted the CCT's to allow for ~6mm of slack on the chain under the chain guide. I also swapped out my plugs, instead of going with 8's i have 9's and as soon as i started it up and warmed up it seems to have a misfire at idle and a crazy backfire upon deceleration. Is it possible its the plugs completely causing this issue to act up? I will be swapping the old ones back in tonight but would like to know if anyone else has experienced this, maybe i need to loosen up the CCT's an 1/8th of a turn? Any advice is appreciated, thanks.
www.vtr1000.org • View topic - Manual Cam Chain Tensioner Installation Guide (MCCT's)
Chain didnt jump any sprockets and i adjusted the CCT's to allow for ~6mm of slack on the chain under the chain guide. I also swapped out my plugs, instead of going with 8's i have 9's and as soon as i started it up and warmed up it seems to have a misfire at idle and a crazy backfire upon deceleration. Is it possible its the plugs completely causing this issue to act up? I will be swapping the old ones back in tonight but would like to know if anyone else has experienced this, maybe i need to loosen up the CCT's an 1/8th of a turn? Any advice is appreciated, thanks.
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Swap out the plugs. easy way to confirm things.
my thought is one of the cams may be one tooth off. can it rev? or does it back fire spit and cough at around ~5-7k rpm?
that's what I was getting with 1 tooth off.
my thought is one of the cams may be one tooth off. can it rev? or does it back fire spit and cough at around ~5-7k rpm?
that's what I was getting with 1 tooth off.
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I doubt it is off by a tooth, it revs solid up to redline, i took it out for a 55 mile ride to see if it would go away at all and it ran fine through all gears without any issues. Only time it is noticeable is at idle and once i let off the throttle, i'll swap the plugs tonight and report what i find.
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Really? I'm certain i had hooked everything back up, even double checked it today when i put the old plugs in. Here's a video of the backfire after throttle, i couldnt get a good one that would how the issue at idle.
I'm guessing the MCCT's are too tight? Should i back them off by an 1/8th of a turn? This is the only thing that has changed.
I'm guessing the MCCT's are too tight? Should i back them off by an 1/8th of a turn? This is the only thing that has changed.
Last edited by bbancsov; Jun 11, 2013 at 04:45 PM.
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I took the tank and airbox to doublecheck all my connections, all were good aside from this one below. It goes to the right side of the front carb and wasnt connected to anything, looks just like a breather line? Any ideas? I have a 2000 mile trip coming up at the end of the month and need to get this thing ready! Any and all help is appreciated.
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vacuum tube
pg. 87 6-12 in the VTR service manual
www.vtr1000.org • View topic - VTR1000F (Superhawk) Firestorm Service Manual PDF
pg. 87 6-12 in the VTR service manual
www.vtr1000.org • View topic - VTR1000F (Superhawk) Firestorm Service Manual PDF
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Did anyone else think of this right away? 
For future reference an overtingt camchain wont cause a backfire or misfire but the bike would struggle to turn over and you may get a squeaching sound a bit like the sound of a fan belt on a car slipping.
(:-})
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Not trying to beat a dead horse here guys but i took a video that better describes the problem. It's the somehwhat "faint" popping sound while at idle, any advice is appreciated i'd like to get it resolved in the next week before i take the bike on a 2000 mile trip! Thanks
video-2013-06-23-15-15-27_zps2e01207c.mp4 Video by bbancsov300 | Photobucket
video-2013-06-23-15-15-27_zps2e01207c.mp4 Video by bbancsov300 | Photobucket
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Not trying to beat a dead horse here guys but i took a video that better describes the problem. It's the somehwhat "faint" popping sound while at idle, any advice is appreciated i'd like to get it resolved in the next week before i take the bike on a 2000 mile trip! Thanks
video-2013-06-23-15-15-27_zps2e01207c.mp4 Video by bbancsov300 | Photobucket
video-2013-06-23-15-15-27_zps2e01207c.mp4 Video by bbancsov300 | Photobucket
It sounds like it's idling too fast and the throttle sync is off. Did you plug that vacuum tube yet? Does it pump 165 psi in each cylinder cold crank pressure? It should sound like this one------
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Yes i plugged that tube when i did the PAIR removal. Is there a way to resynch the throttle tubes? What baffles me is i didnt touch anything when doing the manual cct installation, and thats all thats changed. Nothing else.
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It's a Pain
Only the throttle plates can be synced by turning the sync screw on the left side of the carbs.
Last edited by zxbud; Jun 23, 2013 at 02:09 PM.
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There's something not right there. As long as your 100% certain it's not the PAIR/Vacuum system, I agree with zxbud and think you need to remove the cam covers again and verify that it's all OK. When moving from the rear cylinder (cam lobes pointing upwards and inwards) to the front cylinder, were the cam lobes on the front pointing upwards and outwards. It's very easy to not turn the crank over enough and stop the first time that the FT mark lines up which is wrong. This is why I say to remove both cam covers and verify that you are definitely at TDC on the compression stroke by verifying by the position of the cam lobes. CCT tension would not cause that but timing not right will.
You may also want to make sure that you have no air leaks either at the carb inlets or in the exhaust system also, as this will cause a bit of popping and banging.
(:-})
You may also want to make sure that you have no air leaks either at the carb inlets or in the exhaust system also, as this will cause a bit of popping and banging.
(:-})
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