Carb Tune up – 2008 GV125 Carby

[Amit noble]

Could someone help me tune up the carb and get my bike running smoothly? I have a 2008 gv125. First project with a carburetor.
Already rebuilt it got the bike running. Just need the finishing touches to make it idle smoothly (doesn’t run at all without the choke) and run at peak power.
thank you in advance

[♠️ M77]

Can you get hold of a compression tester ?

Warm up the bike even with choke for 10mins max

Then remove spark plugs on both engines

Put compression tester on front engine spark plug hole => Press start to crank bike for 5 seconds maximum

Record the PSi reading from the gauge

And repeat this for the rear engine

Tell us the engine compression on both cylinders , i feel like it is best to start here first.

If the engine is compressing well above OEM specs , then it is easier to diagnose the carb next

if not , copy these instructions and have your mechanic visit your bike to do it first,  and update us the results.

[madbikeruk]

If compression is good have a look at intake manifold see if it’s split it’s common and it messes with the fueling , unless you have changed something in the carb or done some big performance parts it’s shouldn’t be to far off

idle screw and mix screw  need adjusting if everything else checks out

[Author]

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[Amit noble]

Could someone help me tune up the carb and get my bike running smoothly? I have a 2008 gv125. First project with a carburetor.
Already rebuilt it got the bike running. Just need the finishing touches to make it idle smoothly (doesn’t run at all without the choke) and run at peak power.
thank you in advance

[♠️ M77]

Can you get hold of a compression tester ?

Warm up the bike even with choke for 10mins max

Then remove spark plugs on both engines

Put compression tester on front engine spark plug hole => Press start to crank bike for 5 seconds maximum

Record the PSi reading from the gauge

And repeat this for the rear engine

Tell us the engine compression on both cylinders , i feel like it is best to start here first.

If the engine is compressing well above OEM specs , then it is easier to diagnose the carb next

if not , copy these instructions and have your mechanic visit your bike to do it first,  and update us the results.

[madbikeruk]

If compression is good have a look at intake manifold see if it’s split it’s common and it messes with the fueling , unless you have changed something in the carb or done some big performance parts it’s shouldn’t be to far off

idle screw and mix screw  need adjusting if everything else checks out

[Author]

Posts