140cc Lifan vaccum leak?

[MaxwellRides]

I suspect i have a vaccum leak how can i fix this? thanks:hump:

 

[my67xr]

how come you have started another thread?

where is the leak?
what sort of carby are you running?

if you have a mikuni copy carby,
it may be the big o'ring on the intake manifold side, then buy another one from a bearing shop.
the mounting face could also be warped from doing it up too tight.
if so, remove the oring and use a hard block of flat wood, wrap some fine grade sandpaper around it and rub it across the mounting face.
make sure this is done squarely to the carby too, you will see after a couple of rubs if the sandpaper leaves an even mark across it.
if just the face around each mounting bolt is marked then the carby is slightly warped.
a few more passes should fix this up though.
it also helps the o'ring to seal better.
the plastic carby insulators/spacers can also crack and or warp as well.

if you have an oko or flatslide type carby then the rubber adapter could be warped, and sometimes the bolts that come with it are too long, this doesn't let the rubber seal very well against the intake manifold.
same fix as above, flatten the mounting face with a sanding block.

the other thing to check is the fuel bowl to carby base for warpage, the bowl can carefully be faced with a block and fine sandpaper too.

 

[MaxwellRides]

Yea its a mikuni carb