Hi guys , My 2007 rev3 seems to of started running rough after 5 minutes of warming up there seems to be a clunking noise but the bike seems to run fine , after a hour or so of running it doesnt seem to idle properly , it just wants to cut out , Ive tried new plug , cleaning the carb and trying v power fuel

is air filter exhaust ok anything happen last time out poss plug cap maybe but sounds like it could be running lean causing pinking ,so if carb and jets properly cleaned it could be an air leak or maybe crank seals but hard to say without seeing/hearing it

Zerorev3rev4- Ive repacked exhaust and clean air filter before every outing , is a crank seal a big job if it is that , last time cleaned carb one of the jets had water in it

water had crossed my mind ,could be from washing bike or it could be in the fuel ,clean carb out again removing all parts possible and use an air line or aerosol carb cleaner then drain fuel out frame either check and separate any water found or replace with fresh , to replace seals flywheel would need removing on right side ,on left clutch cover and crank drive would need to be removed but its more likely the carb at fault

Edited April 15, 201412 yr by zerorev3rev4

When you drain the fuel remove the fuel tap and check the filter inside the tank I removed mine when it stuck one day and found a gunge over the filter Also check the tank breather and any in line filter These are easy to check before you delve into the motor

Betas because they have bulky (as in thickish metal) aluminium fuel tanks tend to cool down a lot when not in use. This causes moisture in the air above the fuel to condense on the inside of the fuel tank. The moisture then settles out under the petrol and ends up as sludge on the filter or droplets in the bottom of the carb.

You could try a fuel conditioner (sold to prevent condensation / corrosion in lawnmowers) or put a small amount of methylated spirits (20 cc per litre) in your fuel to absorb the water.

Thanks for your advice guys , tonight i have cleaned the carb , ive also cleaned the airbox which had abit of water in it so im going to look at sealing it abit better to prevent water from getting in , hopefully the carb clean will of solved it as a few particles of dirt came out.