My Son has a Beta Evo 80 which has started to get very hard to tick over evenly ( tickover speed varies) and needs a lot more choke to start even when hot.

 

I have replaced plug, cleaned air filter, cleaned carb to no avail..

 

Appreciate these bikes do not have the refinement  of the larger models but wondering if anyone else has experienced this problem.

 

Ironically at a trial this weekend someone else was having a similar problem on a very new beta..

 

Any thoughts from Beta specialists

check the carb to reed block rubber for cracks,or crank seals !

As above and also the seal where the reed block seals against the cylinder, we had one that leaked at this location.

Also check the throttle cable routing as the 80 is prone to the cable crushing and causing it to stick ever so slightly and giving an iratic idle, but that will not be the starting issue!

ive found they suffer alot with different weather change and  in air temp etc,try adjusting mixture screw i tweek my lads almost every time out

Thanks everyone very helpful.  I fixed the bike last night.

 

Bike now running well and starting.

 

I have carried out all the suggested checks and it turns out the new plug was faulty combined with a mixture screw a mile out.

 

Thanks Barry I never appreciated until I read your reply you had to adjust the mixture screw so often.