Belle mixer problem.

[trialscot]

Hi,
I was given an old but clean Belle mini mix 150 with a B&S petrol engine and thought I was in clover.
Problem is it starts first or second pull with full choke, needs the choke opening about halfway, then cuts out after about 30 seconds, then repeats the process!.
I've put in a new diaphragm and mixture screw, blown all jets through with an airline and replaced the gaskets. Set the mixture screw to 1½ turns out.
Anyone got any suggestions please?.

 

[noseall]

it is the valves you plonka!

they need de-coking (re-seating). you have no compression.

 

[trialscot]

Thanks again.

Yeah, I was coming round to that conclusion - either valve seats, duff springs or broken rings. Lack of sucking seemed to be the problem, isn't it always.

I did de-coke the engine and that was probably a mistake as the carbon round the valves was probably sealing them!. It did run quite well before my attentions.

The job now is to make up a wee tool to lift the springs to get the pins out then find my old double ended tin of Chemico grinding paste, last used in 1969 for a BSA Road Rocket (them were the days!.)