Chainsaw Repair

Good luck on your quest for a good 681 crankshaft. I am not sure that they ever built a good one. I have seen 6 of the 681's that broke the crank. The first two that I had seen had port work done and ran the 272 Husky coils. I assume that the crank couldn't take the higher rpms. The next 4 that broke were on bone stock 681's.
Solo has been good about it. When I get one with a bad crank they replace the whole saw, no age limit. I have to send them the complete old saw for replacement. They will then replace the 681 with a new 675 as they have no 681's left.
If you still want the longer stroke of the 681, I would suggest sending out your Dolmar crank and have it stroked.
Later
Dan

Here is the last 681 broken crank that I had in. The crank is also twisted and you can see the big end rod pin has moved out and it also chewed up the engine case.

Question Dan, when you say twisted, do you mean that the counter weights are now not in line because one has spun a liitle more than the other due to the big end moving? Are they all failing the same?

The answer is yes to both of your questions. Solo tells me that they have corrected the problem with crank failures. The crank that I pictured above was from a 681 replacement saw for another bad crank.
Later
Dan