Grey top 61 rebuild

[roy wilson]

Hi Guys , I,m a newbie on here and have been lurking around a while and have seen great posts , i have a 2013 372 xp a 1996 254 xp and a 1985 grey top 61 , now ..the 61 was a great saw but needed a wee bit of work so ordered up new vibe mounts and new oil pump as there was some wear on the worm gear and the oil seal was allowing oil past into the crank case , and new clutch as it was worn enough that the spring was visible , so when i took it apart to refurb , i decided to take off the cyl and have a good look around , the cyl looked good but the ring land on the exhaust side was very wide which allowed the ring to float , anyhow i decided to ask my local saw shop to see if he had any NOS pistons , and hey presto he did but it was a 48mm piston , then i found the reason the saw pulled so good , at some point a mahle 50mm C&P had been fitted , he said it was a 266 xp top end , but he didnt have the piston for it which had the windows in the skirt, but he had a genuine NOS husqvarna 50mm piston from a 268 xp , which had no windows but the skirt was open on the pin sides so he said it would do the same , as the windowed piston was made for lightness and didnt really line up with transfers so kind of made sense the pinto crown height was the same so anyway i put it all back together and it run real good , but i feel its doesnt pull quite as well as it felt before , so i,m a bit dubious as to whether this piston is correct for this cylinder ??? another thing i seen while trawling the forums that with the 266 xp jug on its best to fit on the HS 244 carb , , while i had it all apart i could't find any ident number on the tillotson carb relating to that number , but there is a serial number on it which is S121A234 , anyone know which carb this is ??, i reckon it is the original 61 carb as it all looks stock and has the idle adjusment screw in the saw case ,as i didnt measure the venturi as at the time he just said well it will be fine , the tilly carb will flow plenty air for that size , so i left it at that , but i think a bigger carb would be some benefit as that would have been why it was fitted to the 266 xp in the first place , , i,m all for picking up some power rather than it just being a runner to cut firewood , thats where the fun is
thanks for any info guys

 

[huskihl]

I'm doing this to a 625 jred, same as a 61. The slab sided piston won't perform as well as a windowed one. The one you got was likely for a 268 non xp, open port motor.

 

[roy wilson]

I'm doing this to a 625 jred, same as a 61. The slab sided piston won't perform as well as a windowed one. The one you got was likely for a 268 non xp, open port motor.

jeez thanks for the quick reply , i did have reservations , the box has an original part number on it , but 268 xp was written on it with byro for quick reference i suppose , if i can still find the box i,ll check the part number , but your right i,m sure , it just doesnt feel the same to me just doesnt have the same torque as it did even with a tired piston and ring