My 2016 did not come with a washer on the fuel mixture screw. I ordered a complete  Mikuni bsr 33 rebuild kit (42$ u.s.from e-bay) and it did come with a washer, spring and o-ring.

Had some difficulty hot starting and then one day when it was really hot, it started loading up at idle. So i turned the fuel screw in 1 full turn (now 1 and 3/4 out) and it made it way better. Another rider told me to not use heavy oil and/or over oil (i used bel-ray before which i love for mx) on the air filter because it will chock it and have slow response. I switched to a lighter/thinner oil and now the bikes starts easy, runs strong, the map settings make a difference so all good now

Now running a 125 main jet, needle clip at the bottom position, bike runs very strong. Fuel mixture screw at 2 and half turns out. Still hit and miss with starting the bike. Anyone notice if  the fuel mixture screw makes a difference in starting?

Mine struggles after big fall ..... When I try to kick it it is hard to turn engine over I have to kick fast a few times to turn engine over properly hard to explain

If i drop my 4t i have to hold the throttle wide open then give it a few kicks, usually starts in 2 or 3. Noticed since turning up the idle it starts a lot better.

Mine struggles after big fall ..... When I try to kick it it is hard to turn engine over I have to kick fast a few times to turn engine over properly hard to explain

Just stumbled onto this post while browsing. I would suggest contacting Billy T through the forum on here. Over the years, both my son and I have received invaluable advise on carb setup on our Beta:s. especially the 4t Beta. Billy knows that carb inside and out and when I was riding a Beta 4t he really helped me transform the bike into what I wanted it to do. It was a huge help/

 

Steve

Mine struggles after big fall ..... When I try to kick it it is hard to turn engine over I have to kick fast a few times to turn engine over properly hard to explain

I would check the intake boot as they tear easily.