Greetings!
I have been running my old Standard cast iron 350 as my daily commuting hack for all of 10 years now. She's always done well and has successfully traversed the north to south and east to west lengths of my country (India) with great aplomb and no fuss, albeit very leisurely.
She's got a custom made roller big end and that's the only mod she has till date. Done nearly 40,000 km on that particular job and about 1.35 lakh km since I bought her off her previous owner. Oh, and she dates back to 1980.
However, of late, she's been acting up. She gets up to 60 kph with no fuss whatsoever but then simply digs in and refuses to go any faster when given the stick. The revs climb, but very slowly, and the engine seems to have lost its fluff. I understand the lack of get-up-and-go that these bikes suffer from and I've been living with that for a decade now. If I need to go faster, my Yamaha is always at hand.
Anyhooo, on pulling open the plug, it was found to be a sooty black. I lowered the needle by one notch and the following was the result:
I realised it was a tad too lean so, I tightened the air screw in by 1/4th a turn. The result was the following:
There is no pinging and I had set the ignition timing with a dial gauge not too long ago. What could be the problem here?
I work on my own bike so please feel free to rattle away any tips that you might have and not the 'please ask the mechanic to check the following' kind of suggestions!
Thanks a tonne in advance!