standard carbs jetting issues

[robbo350]

hey guys running standard carbs with #280mains #30 pilots needle clip on #4

mods are kn filter with kn powerlid boyseen reeds standard airbox and fmf fattys

problem is hard to start when cold seems to flood real easy, and runs abit flat with low revs

just in process of changing crankcase seal on clutch side as it started spitting all the oil out of the breather line. was also told that may have been playing apart in it running rough,

what yas think any suggestions and help will be great

cheers

rob

[4stroker]

the crank seal is not what is causing the oil to spit out the breathers, that is just something these bikes do. i did a ton of research on it when i first got my bansh coz mine does the same thing, and a few of my mates bikes as well. we have figured the ones that get ridden the hardest tend to blow the oil.. we just redirected the end of the breather from pointing at the pipes to pointing at the chain, and keep an eye on your gearbox oil level.

 

if the crank seal was shot it would suck air and gearbox oil into the crank case, not blow it out...

 

it would cause weird running issues though. while you have it apart replace the other seal too and all new gaskets etc to ensure no air leaks. then start your trouble shooting from there..

 

if anything your pilot is probably a little big, try a 27.5.

[AKheathen]

yah, it's loading up with fuel on the low end. 27.5's do sound better, but do a plug chop after you change them to make sure the 280's are still enough

[dajogejr]

A bad crank seal can absolutely pressurize the crank case....and the bike should not spit fluid out the breather line unless it is over filled, tipped over...or...a bad seal.

 

The crankcase gets both, vacuum and pressure in a single rotation.

 

30 pilot is too big for that setup in my opinion...but the crank seal needs to be replaced first.

Do both while you have the cases split.

[BUILDER]

A bad crank seal can absolutely pressurize the crank case....and the bike should not spit fluid out the breather line unless it is over filled, tipped over...or...a bad seal.

 

The crankcase gets both, vacuum and pressure in a single rotation.

 

30 pilot is too big for that setup in my opinion...but the crank seal needs to be replaced first.

Do both while you have the cases split.

I agree. I have never seen a bike that is working properly spit oil out. If you banshee is spitting oil out then you have a problem.