nrg stuttering - runs fine with no air filter? and vacuum

as title realy, i pulled the filter off to see if it was covered in muck, which it wasnt, and the bike ran fine, obviously i dont want to run wtihout a filter, so what do you people suggest? im guessing jetting, but how comes it needs to be changed now? was running fine before..

also if you look in this pic of the carb, you can see what looks like a vacuum hose missing, is there ment to be something there? and if so where can find this?


Help appreicated, thankyou

 

clean filter anyway with warm water, dont use petrol

and it really does sound like a blocked air filter (i had exactly the same problem with a K&N filter i used to have)

but while your cleaning, take carb apart and check jets etc. then reassemble

the spluttering sounds like over jetting, too much fuel so will splutter hence why without an air filter its ok

and that nipple is for lc engines, it takes a feed from the cylinder head to warm up the carb to assist cold starting. If it was running ok before then obviously somethings changed ie blocked jets or block air filter

 

ok, so am i right in thinking that if it runs fine when the filter is off that the filter is at fault? if it was the jets it would do it all the time?

 

sounds like its jetted rich or the filter is restricting air flow, and thats just an overflow pipe, theres one on each side.

 

i cleaned the filter and when i put it on now its worse!

 

dont you mean rich? as in to much petrol not enough air? it runs perfect without the filter! your from croydon arnt you? fancy coming and sorting it out for some moneys?

 

Isit a 21ml carb you got on there?? by the pictures which are up it looks like it is. are you running a standard set up?

 

How would is be not enough air when it works fine without the filter?

 

arc:

not enough air with the filter?

which is why it works fine without it.

 

your airfilter is at fault. my polini big moose does this after it rains and dust and some bits of mud makes it in there.

clean with warm water like advised above. then take a hairdryer and blow from the inside (set hair dryer to fan only or the heat will definately ruin your filter). after you can test with your mouth to see if it's clear.

suck and blow air in and out until you don't feel a slight vacuum.

also clean your carb unscrew your main jet and tap out the needle shaft from the main jet, then check the bleed holes for sand or watever it may have there
also water stick there if you rode it in rain so you need to clean it out, if you don't have a compressor just use a thin wire and poke in the holes. check your floater to see if it swings smoothly, verify the gas hose input this also is the source of problems if your gas filter is dirty, there's bound to be sand in there too that resides just before the entry to your carb, this will halt you gas flow thus making the impression of a lean carb. Clean out and re-assemble the carb and test.