carburation problem

[HoggyF]

Just changed the engine in my boys pitbike and used the old carb, but now its very fluffy off tickover when you blip the throttle, its just bogs down first before revving.

The carb is clean and I've tried adjusting the mixture screw, it was about 1.5 turns out and screwing it in further up to a point improves it up until it goes fully in, which then causes it to stall.

What do i try next?

Oh its a 125, not sure original make but now on a Lifan engine.https://i541.photobucket.com/albums/gg365/HoggyF/IMAG0179.jpg

[N cee thirty]

what colours the plug on idle ?

hows the air filteR ?
____________________
'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[HoggyF]

Haven't pulled the plug out yet but filter is a K&N style and looks clean, now that i think about it how do you clean one of those, I only know how to clean foam panel filters.

What I think I might try next is to pull the plug and have a look and also try it without the filter to see what that does.

[N cee thirty]

probs wash it out with petrol

maybe the carbs not jetted to suite the k&n
____________________
'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[Fortuna]

Was it from the same model of bike/engine?

[69chris]

was the carb ok on the old engine ??
reason i ask is iv just swapped the engine in my lads 110 pitbike, re-used the old carb and had similar probs to what your having, after stripping/cleaning and swearing at the carb i thought id check the valve clearances..............bingo - the exhaust gap had gone !
opened it up a bit and its good as gold, worth checking if you havent crossed that off your check list yet

[HoggyF]

Haven't had a chance to look at it yet but to answer the questions:

Its the same type of engine but as we don't know exactly what bike it is we're not sure.

Carb ran fine on the old engine.

Haven't checked the valve clearances, I assumed they would be set when I bought it but I suppose I should check that really.

i had assumed that the carb would be fine on this engine as they're not that fancy really but probably a bold assumption on my part.