trappermike
ArboristSite Guru
The fact is that chainsaw carbs are pathetically small compared to any normal high performance 2-stroke engine of the same cc's.
A 100 cc motorX engine may have a carb of 30mm,but a chainsaw motor may only have a carb of 15 or so mm. Pretty darn small considering the saw revs even higher. So getting a bigger carb on is a must for more power. The problem is we cant just go buy and stick on a bigger carb 'cause they don't exist. So since the mid 80's I just "bored out" the stock carb larger. This instantly gives a great boost in power to any saw,I've done hundreds. You do have to strip the carb down to the basic block,remove everything,throttle shaft etc.,but doesn't cost you anything.
Tillotson HS carb- bore out to 3/4"
Walbro WJ carb- bore out to 49/64"
You can have a machinist do it but I did it in my shop with a drill press and drill bit.It's a bit touchy,you have to do it carefully and slowly and spray oil on it,no sweat.
A bigger carb and more power for not a penny spent!
I don't know why some people are afraid of carb boring,I've done it since 1986 with no failures.
Also used to bore out the big tillotson HT carb too.
You can port the motor and do everything,but if the carb isn't bigger you severely restrict the motor...
A 100 cc motorX engine may have a carb of 30mm,but a chainsaw motor may only have a carb of 15 or so mm. Pretty darn small considering the saw revs even higher. So getting a bigger carb on is a must for more power. The problem is we cant just go buy and stick on a bigger carb 'cause they don't exist. So since the mid 80's I just "bored out" the stock carb larger. This instantly gives a great boost in power to any saw,I've done hundreds. You do have to strip the carb down to the basic block,remove everything,throttle shaft etc.,but doesn't cost you anything.
Tillotson HS carb- bore out to 3/4"
Walbro WJ carb- bore out to 49/64"
You can have a machinist do it but I did it in my shop with a drill press and drill bit.It's a bit touchy,you have to do it carefully and slowly and spray oil on it,no sweat.
A bigger carb and more power for not a penny spent!
I don't know why some people are afraid of carb boring,I've done it since 1986 with no failures.
Also used to bore out the big tillotson HT carb too.
You can port the motor and do everything,but if the carb isn't bigger you severely restrict the motor...