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Old 14-09-2013, 08:46 PM   #1
bradder's
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bike backfiring and running like sh*t

so was out on my bike today and it ran like shit gargling bogging and back fire like fuck when i got up the rev's and steadly got worst...its still starting fine and was running spot on b4 hand i had the carb off a few time's bcuz i taught it was running lean i cleaned it and blew out the jets the bowl was dirty i have to say (rusty tank) but still no luck..could the spark timing be off? or would it be internal prob like a nackered piston? i still think its a fuel issue but as i said iv tried everything with the carb
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Old 15-09-2013, 01:02 AM   #2
Jeggz
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Re: bike backfiring and running like sh*t

Before you took the carb apart was it running fine? If so, did you make sure that the idle and mixture screws are adjusted the correct way?

Its either a fuel, air or spark issue. Shouldnt be a problem internally i think :-)

Edit. Just re read what you put. Make sure the mixture screw is in the right place, you may have it too rich
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Old 15-09-2013, 05:06 PM   #3
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Re: bike backfiring and running like sh*t

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Originally Posted by Jeggz View Post
Before you took the carb apart was it running fine? If so, did you make sure that the idle and mixture screws are adjusted the correct way?

Its either a fuel, air or spark issue. Shouldnt be a problem internally i think :-)

Edit. Just re read what you put. Make sure the mixture screw is in the right place, you may have it too rich
yeh the screw's where set right and no thats why i took it off it was running like shit i had the inlet off the was a air leak but glue and duck taped it up lol and its still the same is there any way to check if its sparking right? keep in mind its starting on the button
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Old 15-09-2013, 05:32 PM   #4
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Re: bike backfiring and running like sh*t

to check that it is sparking , undo the spark plug from the head and take it out, leave the HT cap on and rest the thread (or any other metal part of the plug) onto something metal, the engine is fine, or the exhaust. when you press the electric start or kickstart it you should see a nice constant, strong spark between the two gaps of the spark plug. whilst the plug is off have a look and see what colour the plug off. brown=good, black=not so good, and black/deposits of soot= no good.

if its not sparking, then a new plug is needed and if the plug is proper black, adjust your mixture
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Old 16-09-2013, 05:06 PM   #5
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Re: bike backfiring and running like sh*t

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Originally Posted by Jeggz View Post
to check that it is sparking , undo the spark plug from the head and take it out, leave the HT cap on and rest the thread (or any other metal part of the plug) onto something metal, the engine is fine, or the exhaust. when you press the electric start or kickstart it you should see a nice constant, strong spark between the two gaps of the spark plug. whilst the plug is off have a look and see what colour the plug off. brown=good, black=not so good, and black/deposits of soot= no good.

if its not sparking, then a new plug is needed and if the plug is proper black, adjust your mixture
cheers lad il check my plug now...and the spark plug is getting fouled (autolube needs adjusting) was thinking of just running premix
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Old 16-09-2013, 09:08 PM   #6
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Re: bike backfiring and running like sh*t

Wait, what bike is the problem on? 2 stroke? Not a pit bike?
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Old 17-09-2013, 01:48 AM   #7
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Re: bike backfiring and running like sh*t

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Wait, what bike is the problem on? 2 stroke? Not a pit bike?
haha sorry lad its a 2stroke yamaha tzr 125 i no this is not a road bike fourm but i get more help here then on the 2stroke fourms
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Old 18-09-2013, 10:20 AM   #8
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Re: bike backfiring and running like sh*t

Id be trying a new plug and ht lead and cap.
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Old 18-09-2013, 06:19 PM   #9
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Re: bike backfiring and running like sh*t

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haha sorry lad its a 2stroke yamaha tzr 125 i no this is not a road bike fourm but i get more help here then on the 2stroke fourms
Doesnt matter too much anyway. If its sparking fine then your gonna want to check your air filter, if its proper dirty and dusty, give it a clean. And temporarily run the bike with it off. However i seriously warn you DO NOT RIDE IT LIKE IT and make sure your environment isnt really dusty. With the bike standing, rev it and see if it bogs down; if it does, the air filter is not the issue. If it runs fine then your air filter is the issue.

Following the path of air flow, if the air filter isnt the problem and you still have no remedy then check the exhaust. It might be coated with soot considering its a two stroke, which would block air flow and bog you down. The same with a blockage in the head where the exhaust goes in.

If you still have no luck then i dont really know. Maybe the jet in the carb is too big? Or your chokes on? or stuck in position? Be funny if it was!!!!
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Old 19-09-2013, 12:51 AM   #10
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Re: bike backfiring and running like sh*t

Quote:
Originally Posted by Jeggz View Post
Doesnt matter too much anyway. If its sparking fine then your gonna want to check your air filter, if its proper dirty and dusty, give it a clean. And temporarily run the bike with it off. However i seriously warn you DO NOT RIDE IT LIKE IT and make sure your environment isnt really dusty. With the bike standing, rev it and see if it bogs down; if it does, the air filter is not the issue. If it runs fine then your air filter is the issue.

Following the path of air flow, if the air filter isnt the problem and you still have no remedy then check the exhaust. It might be coated with soot considering its a two stroke, which would block air flow and bog you down. The same with a blockage in the head where the exhaust goes in.

If you still have no luck then i dont really know. Maybe the jet in the carb is too big? Or your chokes on? or stuck in position? Be funny if it was!!!!
ha well i know my choke's working cuz its hard to start without it. and i think its a electric issue the spark is yellow the odd blue flash (it should be good strong blue right?) and the bike shorted out on me 1 of the nights b4 it ran like it is lost all lights and elect (it was dark) it was dodgy wire earthing off the frame..could of fryed sumting else :/
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