Normal
His email keeps getting hacked and I get spammed. I have had two of his bigbore 125's and they work/worked very well. In the past he hasnt promoted 125's to 134's since it was about the same to make one a 144. but the 134 was a great way to build a legal 125 in the day that had a stronger midrange (due to the retardation of the transfers from boring). Again, yours doesnt look lean to me. If it was mine I would treat the cylinder with muratic acid to remove the aluminum, light hone on the affected area and 600 grit wet and dry on the piston. new ring. gapped no less than the middle in acceptable range.I don't usually use a higher oil to fuel ratio for breakin (though companies like yamaha suggest it) on my plated cylinders. I run 20-1 in my 125's constantly. Yamalube. I think if I was having the result you report I would go to a little longer warm up and the 20-1 for at least a couple of tanks. But literally, when mine are runnging clean without the choke/enrichenor I am pulling away.We didn't talk about how old your spark plug is and looking at it may be trying to read through lots of different conditions if it was used. IE not the ten minutes of age the piston was reported to be. I think you are still looking for at least one air leak, and I would start at the crank seals. If it was mine it would be topend on, bdc and pressurized to about 10 lbs and I would be spraying soapy water everywhere two surfaces met.
His email keeps getting hacked and I get spammed. I have had two of his bigbore 125's and they work/worked very well.
In the past he hasnt promoted 125's to 134's since it was about the same to make one a 144. but the 134 was a great way to build a legal 125 in the day that had a stronger midrange (due to the retardation of the transfers from boring). Again, yours doesnt look lean to me.
If it was mine I would treat the cylinder with muratic acid to remove the aluminum, light hone on the affected area and 600 grit wet and dry on the piston. new ring. gapped no less than the middle in acceptable range.
I don't usually use a higher oil to fuel ratio for breakin (though companies like yamaha suggest it) on my plated cylinders. I run 20-1 in my 125's constantly. Yamalube. I think if I was having the result you report I would go to a little longer warm up and the 20-1 for at least a couple of tanks. But literally, when mine are runnging clean without the choke/enrichenor I am pulling away.
We didn't talk about how old your spark plug is and looking at it may be trying to read through lots of different conditions if it was used. IE not the ten minutes of age the piston was reported to be. I think you are still looking for at least one air leak, and I would start at the crank seals. If it was mine it would be topend on, bdc and pressurized to about 10 lbs and I would be spraying soapy water everywhere two surfaces met.