B & S ignition timing

Hello Graham...

 I did once upon a time...but these days I am but a simple gardener
...although I still get to look at the machines at work...this week possibly..given the forecast.!!

 I have a bit of a love hate relationship with machinery these days... I used to like to puzzle things out and beat a poorly machine...hence I suddenly felt the need to post on a few observations from the sidelines in this case just in case they may help.?..but equally these days I much prefer garden muck to machinery filth....as my old mate John in my former employment used to say..."they only bring them here cos they want them cleaning"....or in the case of an electric machine.." cos they want the cable untangling"...such was his sense of humour.    

Garden muck is clean muck

"Dori'"

Hello Graham,
 I was on YTS scheme when it was 6 months and then out ....working at a local sales/service agent..I remained there for 18 months all told...until they had another idea...then a spell with a local council walking behind a Vergecutter76, Bunton and Victa and then a move back to the sales/service/spares..I helped a guy build up his machinery business over 8 years...sadly with his ill health and rent increases etc, etc I was there when it all sadly went pop...we had plenty of work/spares sales and happy customers but the business was, I would describe, as an in between size..not big enough to command large discounts on new machines and spares but had grown out of the owners original secondary work "garden shed" based repair business.  
 We held Qualcast/Suffolk/Atco/Webb, Flymo repair agencies..and Wolf Garten Sales and Repair agencies..I used to enjoy sales of the Wolf 'lectric mowers as they did exactly what the literature claimed..powerful induction motors and grassboxes that would fill to the top even in long or wet grass conditions...I knew what I was telling a potential customer was absolutely the word....

At work these days we still retain I think one machine with points ignition  B&S 3hp on a 1981 Marquis Mk5M...a real Marquis. We also have a  1995 one with onset of rotary mower laws on the cylinder mower..all for the best of safety motive I fully appreciate..but leading to a hunched tiring stance in operating with the 1995 model. :?   To be fair I have not used the motiv-air model as we have not got that new yet :oops: so I best go no further with my soapbox  :?

I add...as of todays date I've been 16 years as a gardener...

..and I'm bending the thread off topic....sorry :oops:

regards,
     "Dori"

sounds to me like the poor old beast is suffering with more than one problem at once.
if it still wont fire, it's strip the carb time. I wonder if you should get a carb diapragm while you're at the briggs shop?
good luck.

Success!!!!
Well - nearly!
Having walked away from the problem I had chance to think the problem through. I came to the conclusion that gwiz was right when he said it was a combination of small problems all working together.
I put the engine back on the bench and stripped it once more. I replaced the valves with a pair in better condition, out of another engine, and lapped them well in. I replaced the magneto with another that I knew was giving a strong spark and reset the new condenser and points at 18thou. I also replaced the diaphram in the carb (again) and, at the same time, took the opportunity to blow the jet out. I also rewound the starter cord because it was not retracting as it should. I checked the gap on the new plug and put the engine back onto the machine.
Choke engaged - two gentle pulls to prime and - pull. Splutter, splutter, stop. Try again with the fuel needle closed slightly and - away she goes!!
30 seconds later she stops and will not restart! I've lost the spark!
At least I know she runs and it is a simple job to check the ignition system again. Job for the weekend.