Re: Force 125 powerhead replacement
Buy a Clymers, it's relatively complete.
For easiest removal and assembly, you need to remove everything from the block: Flywheel, head, Carbs, ignition, starter, etc. Below the carbs are six 9/16 heads 3/8 bolts on the match plate and in the back below the lower pan are six nuts on 3/8 studs. You must remove the rear shroud and the lower pan to easily access these bolts and nuts. You must also remove the shift rod nuts. Four internal 3/8 bolts hold the match plate to the block and these will be removed after the block is lifted off the head.
Now the easy part is done. You must now use the pry points to break the seal between the match plate and the midleg. And the studs will most likely have some corrosion on them making it difficult to raise the block. This will be the most difficult step of the whole process. You will need a new base gasket to mate the new block to the match plate
The block, crank, and pistons weigh about 80-100 pounds so you will need a hoist or a friend if you are not a strapping young fellow.
The exhaust down tube has a flange on it which will interfere with the upper water tube mount in the midleg, so for both removal and installation, you must "wiggle" and turn the block a bit.
Figure about 5 hours removal and a little less for assembly. So allow a whole weekend for the job. You will need a couple of screwdrivers, a pliers, hand and socket wrenches and a torque wrench. You will also need some sort of flywheel puller (steering wheel puller MAY do) and some tire irons or pry bars.