Big Woody
ArboristSite Operative
I encountered 2 glitches with this yesterday and thought I'd pass along in case someone else may be interested. I re-drilled a new 41 inch Stihl rollernose 088 .404 bar (123 drive links) and used an old 090 25-30 inch .404 hardnose as a template. Both the adjuster (tensioner) and oil holes needed to be re-drilled. Also the slot was in the same position with respect to the rear of the bar on both which is good. I aligned the slots in both bars to mark the new locations. The 090 oil hole in the old bar went through both rails which made marking the new oil holes easy.
The good news:
With a new TiN coated bit from Harbor Freight and a few drops of cutting fluid the drilling was pretty easy. I used a Jet floor drill press set on the slowest speed (around 200-240 rpm). I guess sharp bits help. I drilled the adjuster holes through the bar and the oil holes through one side only of the rail.
Problem 1: When the tensioner plug was all the way rearward I could not stretch the chain (123 Drive Links) enough by hand to get the plug in the new hole. I ended up using a dremel to ovalize one of the holes forward. If I had to do it again I would move one tensioner hole about 1/16 + inch towards the nose to avoid this. Once the chain stretches a little the other new hole will work as well in its original spot.
Problem 2: The new oil hole still fell in the oil well of the bar but just touched the forward inside edge of it. After installing the bar the oiler didn't work and I discovered the new oil hole was still just barely rearward of the oil slot in the case. Hence I had to drill another oil hole in the bar. I drilled it near the front of the slot in the case. As the chain stretches, this front hole will move forward out of the slot as the rear hole moves into the oil slot in the case. This new oil hole is obviously not in the oil well of the bar unfortunately (but way forward of it).
An alternative solution may be to add an extra chain link to move the bar forward and then the original drilled holes may work. However not knowing this ahead of time I ordered a 123 link chain as recommended and didn't realize the problems till after the holes were drilled.
FWIW
The good news:
With a new TiN coated bit from Harbor Freight and a few drops of cutting fluid the drilling was pretty easy. I used a Jet floor drill press set on the slowest speed (around 200-240 rpm). I guess sharp bits help. I drilled the adjuster holes through the bar and the oil holes through one side only of the rail.
Problem 1: When the tensioner plug was all the way rearward I could not stretch the chain (123 Drive Links) enough by hand to get the plug in the new hole. I ended up using a dremel to ovalize one of the holes forward. If I had to do it again I would move one tensioner hole about 1/16 + inch towards the nose to avoid this. Once the chain stretches a little the other new hole will work as well in its original spot.
Problem 2: The new oil hole still fell in the oil well of the bar but just touched the forward inside edge of it. After installing the bar the oiler didn't work and I discovered the new oil hole was still just barely rearward of the oil slot in the case. Hence I had to drill another oil hole in the bar. I drilled it near the front of the slot in the case. As the chain stretches, this front hole will move forward out of the slot as the rear hole moves into the oil slot in the case. This new oil hole is obviously not in the oil well of the bar unfortunately (but way forward of it).
An alternative solution may be to add an extra chain link to move the bar forward and then the original drilled holes may work. However not knowing this ahead of time I ordered a 123 link chain as recommended and didn't realize the problems till after the holes were drilled.
FWIW
