I finally got my beta running forwards again after replacing the flywheel key, but when I started it up it was still not sounding right. My gfs dad reckoned the mixture was too rich so we tried unscrewing the mixture screw slightly. It started sounding better and better and wasnt missing beats as much. Problem was the screw became quite loose when it was at the right position, I should've known it would fall out. Spoke to my gf's grandad(pre 65 obsessive compulsive) and he suggested carving a bit of wood to plug the gap left by the missing screw, just until i can get a replacement. Tried running the bike like this and it seemed fine-ish, I think it might be a little lean though, as the engine sounds higher/faster than normal when idling. Is it bad for the bike to run it like this?

Also when I do get a replacement, I'm concerned that there is something up with the carb as I doubt the mixture screw should have to be unscrewed that much in the first place. Dont want to lose it again.

thanks in advance for any help

The mixture screw is generally used for fine-tuning a bike and if adjusting it is resulting in dramatic differences in the performance or general running, this is probably an indication of a problem elsewhere. For example, is the air filter completely clogged (or holed)? Is there an air leak somewhere - maybe the rubber boots on the carb/airbox or carb/intake manifold have holes or spilts?

They all seem fine, I'm assuming the problem is too much petrol is getting through. Problem is I dont know much about carbs and I dont want to mess around with it and cause more problems. I checked out the link about carb setup on the other carb thread but cant say that I understood it much.

Had a look inside the carb today, and according to this

http://www.r2wtrials.com/images/beta/carb/...20-%20After.jpg

my tangs are at the wrong level, they definetly are not pointing towards the top of the pilot tower, more like horizontally. What kind of different does this make? How can I adjust the level they sit at?

Also the pipe that comes out the backside of the carb was resting against the exhaust pipe, and had actually melted so that it was sealed.

So how do I set the level the tangs rest at when holding the carb upside down? Somebody suggested bending them, but there must be a better way than that?

nope I don`t think so I just bent mine just the little bit they rest on of course and what with it being brass this is very easy to do and they don`t really ever come under any strain and brass is very maleable (sp?) so will not cause any stress problems within the material

Many thanks!