jets on scooter

[con]

do i have to upgrade the jets if i have put new rollers in and its been de-restricted??
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con

[oldbiker]

only change the jetting on a carb if you alter the exhaust or have some porting work done to your barrel or head.

if the bike starts and ticks over the pilot and choke jets are ok.

if the engine backfires at full throttle or near full throttle you need to go up a couple of sizes on the main jet.

check the colour of the plug after a mile or so of fast riding it should be the colour of a ginger nut biscuit, if it`s darker reduce the main jet size, if the plug is lighter than a rich tea biscuit increase it by a size or two.


also look very carefully at the insulator of the plug if the deposits on this part of the plug show a grey colour the ignition timing is a little bit advanced,

if the spark plug electrode shows signs of melting the engine is suffering from severe over heating.

is that any help?
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It`s all powerfull white mans magic
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[con]

thanks thats loads of help, the pipe is upgraded to a ginelli one so do u think i should definitely upgrade the jets???
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con

[steo]

Yes go up about six sizes on your main jet to allow for the pipe. Look at the jet size number stamped on the jet & if it says e.g. '60' then install a 66. Here's a website you maybe interested in, https://www.tunemyscooter.com/50cc-tuning/suzuki-katana-ay50-race-tuning-guide/

[oldbiker]