Geo-TH,In
Well-known Member
My Jubilee carb needs 4 1/2 turns on main jet to run in cold weather. At 2 1/2 turns,my summer adjustment, spark plugs are white as snow, no deposit, looks like new.
After installing an ETG, which I got off ebay for $22. I ran it hard for 20 minutes mowing yard in second gear to get a temp reference point, then I turned the main jet in 1/4 turn. EGT went up just a needle width. Ran it another 20 minutes and cranked main jet in another 1/4 turn. Noticed more of an increase in EGT. Meter is just an indicator with numbers, no actual degrees.
Engine ran without any issues, no loss of power. No run on, dieseling, when I shut it off either.
My question is, can getting it close to the ideal fuel to air ratio cause too much heat and pop a hole in piston?
Or what causes pistons to get a hole in them just below the spark plug? Too hot of a plug?
Or should I push my luck and go for even leaner? I know form a life time of adjusting carbs, going too lean engine will stumble, just like it does on winter fuel and sub zero temps.
Thanks
George
After installing an ETG, which I got off ebay for $22. I ran it hard for 20 minutes mowing yard in second gear to get a temp reference point, then I turned the main jet in 1/4 turn. EGT went up just a needle width. Ran it another 20 minutes and cranked main jet in another 1/4 turn. Noticed more of an increase in EGT. Meter is just an indicator with numbers, no actual degrees.
Engine ran without any issues, no loss of power. No run on, dieseling, when I shut it off either.
My question is, can getting it close to the ideal fuel to air ratio cause too much heat and pop a hole in piston?
Or what causes pistons to get a hole in them just below the spark plug? Too hot of a plug?
Or should I push my luck and go for even leaner? I know form a life time of adjusting carbs, going too lean engine will stumble, just like it does on winter fuel and sub zero temps.
Thanks
George
