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Motorcycle Repair/1995 suzuki gn 125 missfire?


Hi  I have recomisioned the bike after 10 year off road new carb new coil ht lead and plug, new air filter new battery. The bike starts  and responds to the choke, can rev up to red line no problem then when I get on the road the bike will run ok until you ask for more revs at about 6 to 7 thou starts to miss and loose power if I open the excelerator slowly it will rev higher but obviously by then the bike has slowed too much and you have to drop a gear and the problem starts again thanks brian.

Hello Brian,

Sounds like lean mixture...
Assuming that fuel tank and fuel cock are O.K. and fuel delivery is normal, let's start troubleshooting...
First of all, check if I.D.# is the same on old and new carburetor. It is located just under the vacuum slide cover mating surface on the right side of the body. It should be something like "05300" or "0540".
If it's the same, proceed step two: is the "UP" mark on the air cleaner cover pointing up?
Is there a snorkel on the cover, or just a straight opening to the air cleaner element?
It should look just like in the attached picture.
Next, check if the tube (#4 in the picture), connecting carb to the air cleaner box, is airtight both ends.
Needless to mention that the box itself should have no cracks, holes, or extra openings besides the snorkel.
See that no carb's breather hose is obstructed or crimped by any means.

If all of the above fails, please feel free to come back any time...

Best Regards,

Motorcycle Repair

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Lazaros Ampatzidis


I can help you on EVERY issue involving POST-1980 Japanese Motorcycles plus KTM and Husaberg. My field of expertise includes Engine, Transmission, Fuel system (carburation & EFI),Electrics and Electronics. Maintenance, repair and tuning. Road and off-road suspension tuning. Please don't ask me about non-Japanese Motorcycle, especially American built on which I have low to zero experience.


I'm a rider and hobbyist since childhood. 25 years motorcycle workshop mechanic.15 years motorcycle racing mechanic. In order of experience high to low:Kawasaki,Suzuki,Honda,Yamaha,KTM,Husaberg.

Hellenic (Greek) Technical School.Internal Combustion Engines Engineer. Automotive Electronics.

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