Hey folks, I'm a complete newbie here and that's my first post. Sorry for my eventual mistakes and bad english (I'm from Poland).
Buddy of mine gave me a saw couple of days ago to play around with it but unfortunately I think I might wasted the cylinder. I'm not surprised cause I'm a beginner and need to learn basically everything but I feel bad and want to fix that if I can.
It's basically an Active 56.56 but it's branded as Maruyama MCV5600.
It has around 54.5cc, bore 45mm and stroke 34.3mm, stock timing numbers were:
squish - .057"
exhaust opening at 105.5
intake opening at 68
transfers opening at 127, blowdown 21.5
After base gasket delete before grinding:
squish - .020"
exh 110
in 71.5
transfers 130
My numbers:
ground exhaust back to 105 just to be safe and eventually come back and grind more
intake 76
transfers 125, set the blowdown at 20
I think I might have went too far on the intake and that's why it's spitting back, before I also took out the bottom piston ring but that created more problems and then the saw was puking gas out of the carb because when the empty ring groove was passing the transfers some of the charge was pushed back to the intake, but I've put that ring back in and it helped in some degree bot not completely. In the past when I was playing with smaller and bigger saws I've been setting the intake opening from 70 to even 80 degrees and they were not spitting back or maybe just a tiny bit. Also I'm gonna put some pictures for a better look if they can help any.
View attachment spitback.mov
Buddy of mine gave me a saw couple of days ago to play around with it but unfortunately I think I might wasted the cylinder. I'm not surprised cause I'm a beginner and need to learn basically everything but I feel bad and want to fix that if I can.
It's basically an Active 56.56 but it's branded as Maruyama MCV5600.
It has around 54.5cc, bore 45mm and stroke 34.3mm, stock timing numbers were:
squish - .057"
exhaust opening at 105.5
intake opening at 68
transfers opening at 127, blowdown 21.5
After base gasket delete before grinding:
squish - .020"
exh 110
in 71.5
transfers 130
My numbers:
ground exhaust back to 105 just to be safe and eventually come back and grind more
intake 76
transfers 125, set the blowdown at 20
I think I might have went too far on the intake and that's why it's spitting back, before I also took out the bottom piston ring but that created more problems and then the saw was puking gas out of the carb because when the empty ring groove was passing the transfers some of the charge was pushed back to the intake, but I've put that ring back in and it helped in some degree bot not completely. In the past when I was playing with smaller and bigger saws I've been setting the intake opening from 70 to even 80 degrees and they were not spitting back or maybe just a tiny bit. Also I'm gonna put some pictures for a better look if they can help any.
View attachment spitback.mov
