"I got a free 70hp 3 cyl from
"I got a free 70hp 3 cyl from the early 80’s. Compression was 70-105-105. The top cylinder had major problems so I opened her up last night. The first thing I found was the rod bearing was toast, and some foreign object had made its way in to the cylinder and done major damage to the top of the piston and combustion chamber. Maybe it was a piece of rod bearing because a small area of one port was damage also? I can feel that the rod and crank are not perfectly round from the bearing problem, feels like small indentations. So, I’m new to 2 stroke rebuilds so I have some questions for all you guys.
Can you grind the crank journals down and use over sized bearings like you would in other motors? If not what do you do to fix a bearing failure?
I think I could reach in and repair the damage to the combustion chamber with a die grinder, anyone done this? anyway to pressure test the cylinder?
The gear housing input shaft is to hard to turn by hand, but easy with pliers, is this normal?
Thanks Cole"
"I got a free 70hp 3 cyl from the early 80’s. Compression was 70-105-105. The top cylinder had major problems so I opened her up last night. The first thing I found was the rod bearing was toast, and some foreign object had made its way in to the cylinder and done major damage to the top of the piston and combustion chamber. Maybe it was a piece of rod bearing because a small area of one port was damage also? I can feel that the rod and crank are not perfectly round from the bearing problem, feels like small indentations. So, I’m new to 2 stroke rebuilds so I have some questions for all you guys.
Can you grind the crank journals down and use over sized bearings like you would in other motors? If not what do you do to fix a bearing failure?
I think I could reach in and repair the damage to the combustion chamber with a die grinder, anyone done this? anyway to pressure test the cylinder?
The gear housing input shaft is to hard to turn by hand, but easy with pliers, is this normal?
Thanks Cole"