I posted bar/chain and sprocket numbers above. Should the sprocket at the end of the bar (7) have same number of teeth as the drive sprocket (6). Should there be any end float on the drive sprocket when assembled and torqued correctly? Why will only walk off the sprocket when rolled backwards and only bind when going forward? While viewing sprockets the other day I noticed several had 6 or 7 teeth under the same part number. My saw is a 18 inch Poulan Wildthing?? There are several different typrs but I can,t figure out the type. I boughtit new in late 90,s
No
The number of teeth in the nose sprocket is determined by the radius of the nose.
A thin trimming bar will have a thin nose & small sprocket while a wide felling saw will have a much wider one,
If the sprocket is the right one & the bar is the right one and the sprocket bearing is good ( should be replaced with the sprocket ) then the last thing is the alignment of the bar
If the bar is not dead true to the sprocket you can get this sort of situations but that normally only happens when ou change a bar in the field & fail to clean the bar area or the tensioning pin is not located properly in the bar.
There is only so much we can do when we have noting to go on but what some one has typed into a forum.
Many times the key is what damage was done which required the repair.
And I would ask why are you changing the bar ?
Bars should be a forever item unless the owners is abusing the saw or the lubrication system has failed .
My personal saw is a Stihl Farm Boss bought in 1982 when I lived in the mountains .
It cut 3 ton of fire wood or me every year for 30 years plus was regularly loaned to the fire man next door during bushfire or for cleaning up storm damage & has been loaned to at least 50 customers since I bought the repair business and it is still on the original bar .
I inherited an 07 Lightening from the 60's with the store stock and that is also a loaned and it still has the original Stihl bar .
So your problem could still be what ever it was that caused you to replace the bar in the first place.