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Knock, Stall and Backfire through the rear carb

Old 11-06-2012, 06:06 PM
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Knock, Stall and Backfire through the rear carb

I'm having issues here. This is my first Hawk it is an 01, dynojet kit, k&n air filter. Since i got the bike about amonth ago i have had an issue of the bike knocking pretty loud randomly and sometimes the bike stalls. I have looked over everything i could think of to check for the cause of the problem and while i was putting tires on the bike last weekend i figured i would pull the plugs out and look at them, found the front to be way over gapped and the rear to be under gapped, both clean no signs of running rich or lean. (the engine does run a bit rich at idle) So i regapped them rode the bike all weekend put about 200miles on it, (problem still occuring durring ride) and today since it rained and i had time i went ahead and pulled the plugs and replaced them, gapped the plugs to .35 and put the bike back together. When i started the bike it ran great for the first few min, then i reved the engine up to 2k and held, the knock was still there (happening every 3 to 5 seconds) so i removed the air filter and started the bike again while watching the carbs, when the noise happened i didnt notice anything at first but then the rear cylinder started back firing out of the carb right after the noise happend. Im at a loss here, i dont have a clue what would be causing this, the nock can be heard clearly and can be felt in the bike when it happens. Does anyone have any suggestions for me here? I am trying to avoid paying someone to fix my bike for me when i am an automotive technition and am very good with engines, just dont have much experience with something this tiny.
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Old 11-06-2012, 06:11 PM
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Balance the carbs and up the idle to 1200 - Carb fart is quite normal, raising idle a notch will help prevent stalling at low speed. Remember these are monster carbs.

dynojet kit, k&n air filter
Were these plug'n'play mods? as for best gains they need to be carefully set-up on a dyno by someone who knows what they're doing.

Last edited by Wicky; 11-06-2012 at 06:15 PM.
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Old 11-06-2012, 06:18 PM
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Originally Posted by Wicky View Post
Balance the carbs and up the idle to 1200 - Carb fart is quite normal, raising idle a notch will help prevent stalling at low speed. Remember these are monster carbs.

Were these plug'n'play mods? as for best gains they need to be carefully set-up on a dyno by someone who knows what they're doing.

Now that is something that i'm not so sure was done was the carbs being synced, how can i go about this at home? And the "carb fart" is understandable but the loud knock that comes before it doesnt sound like the back fire though the rear carb and actually sounds as if its coming from the front cylinder, where as the backfire is coming from the rear. These mods were done by the previous owner by his technition and the bike was tuned on a dyno.
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Old 11-07-2012, 06:09 AM
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Originally Posted by VTRsurfer View Post
Ditch the K&N air filter for an OEM filter.

I'm purchasing a stock air filter friday to install on the bike, but that wouldnt cause the loud ping/knock at idle and at 2k free rev.
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Old 01-07-2013, 05:13 PM
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mine dose the same thing how did you go ??? i want to solve this.
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Old 01-08-2013, 09:50 AM
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get a service manual.
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Old 01-08-2013, 11:19 AM
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If you guy's haven't done it yet read the articles on carb setup, TPS adjustment, and PAIR valve removal in the knowledge base!
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Old 01-11-2013, 06:27 AM
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Originally Posted by HRCA#1 View Post
If you guy's haven't done it yet read the articles on carb setup, TPS adjustment, and PAIR valve removal in the knowledge base!
+1...Sailorjerry and sjscicluna, listen to these ^^^^^guys. You gotta search some of this stuff on the site. Check the Knowledge Base and "sticky" tech articles and you shall learn that your experience has already occured sooooo many time before to others. Every prob I have ever encountered with my bike is posted somewhere in this forum. Read, read, read!

The service manual is downloadable here at this link: https://www.superhawkforum.com/forum...-manual-11365/

Then after you complete some of the requisite procedures and are still having probs...ask.
Good luck with your bike!

Last edited by tbartley; 01-11-2013 at 06:44 AM.
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