On Wednesday, April 27, 2016 at 9:36:38 AM UTC+1, Another John wrote:


My old B&S-powered mower never starts. Not, that is, unless I spray a
couple of bursts of "Sure Start" into the carb. Then it starts first
time, and always starts after that, once it's hot. (Another regular
mentioned that spraying gas from a blow torch (i.e. not lit, obviously!)
into the carb works just as well.

This great tip got me our of trouble - excellent tip. Luckily I had a so-called 'weed wand' a.k.a. blow lamp with long neck for burning weeds. It was fairly easy to prop this up against the underside of the air cleaner while holding the throttle open and pulling the rope (without needing three arms)..

I still wish I could cure the starting problem though. I bought a brand new carburettor, complete with diaphragm, gasket and o-rings etc, but it didn't make a ha'p'orth of difference. So I now suspect the ignition system. I cleaned up the spark plug but that didn't help. I pinched the plug gripper together slightly inside the suppressor cap, but that didn't help. I guess I could try buying a new spark plug and see if that helps, otherwise, I don't know what to try... A new coil perhaps? I don't really understand how the spark is generated on these motors. Clearly there is no contact breaker (unless it's hidden somewhere). Clearly the spark must be occurring, or it wouldn't run at all. I tried shortening the throttle cable to that it really does open to the max when starting. The carb doesn't have a separate choke or limiter cable. The motor does pulsate a bit rather than running dead evenly. I also notice a little bit of smoke coming from around the silencer-thingie after I shut the engine off.

Al