What type help were you looking for? First, the engine can come out by just taking off the valve cover and putting a transmission jack beneath and removing the motor mounts. Then, you have have to pull the engine by sliding it out the right side. Help is GOOD here as it is awkward but I can and have done it by myself. Once the engine is out, I use a furniture moving dolly to set the engine in and work on it. You might want to take all the engine covers off the engine BEFORE you pull it though as splitting the cases requires removing the engine covers and cleaning all the gasket mating surfaces. This includes the kicker, the clutch, the inner points cover, the stator and the inner countershaft covers as well as the oil pan but you can leave the oil pan till the engine is out.
OK, once the engine is out and the covers are off, pull out the starter. Then remove the FIVE (5) case bolts that come in from the top located around the starter. I take the time to chase the thread in the holes with a tap and wire brush the thread on the bolts. (Do this with the bottom ones as well). The thread is 6mm 1.0 pitch.
Then you put the valve cover on and roll the engine over leaving it on the furniture moving dolly so the bottom is facing up. You can pull the oil pan at this point and clean it out good (will be full of crud) and then remove the oil pump. It is held by a couple bolts... There is also an oring or two under so don't loose them.
Then you remove the engine case bolts. There are 17 of them I think... all are 6mm (10mm socket) and the two outside ones along the crank are 8mm (12mm socket). Once the bolts are removed, take a tap and chase out the thread on the THREE 8mm starter threads; two in the front and one in the back. These threads are in place so you can stick an 8mm bolt in there (8mm x 1.25 pitch) and when you crank down on the bolts, it breaks the seal in the cases; making them VERY easy to split. If you don't clean the thread, the bolts are usually almost impossible to turn.
Anyway, use three 8mm bolts to split the cases once the case bolts are out... DO NOT FORCE... the cases come apart easily and if they don't appear to budge, you missed a bolt somewhere. Once you have the cases loose/split, you just lift the bottom off.
You will see the crank in front part of the engine. You now need to take the inner 8mm bolts out. I think there are four left (might be six?)... anyway, these are the bolts holding the crankshaft keeper. Straddle the engine and use a breaker bar as it is hard to leverage these bolts since the engine is on the furniture moving dolly which is on casters and will want to slide around.
Take off the crank keeper and now you can lift the crank right out. Just pull the old chain off and slide the new one on. You might want to have a manual and measure big end play and other bearing related clearances but it isn't really necessary. While in there, you can also easily look at your shift forks and gears for wear. If you take out the transmission, there may be half moon shaped locating pieces (sort of like half a piston ring type things). These are used to locate the transmission ends and they just sit in slots so might be easy to lose. Keep an eye out for them if you pull the transmisison.
EVERYTHING goes back into the cases in only one way so you won't get the cases back together if anything is not fitted properly. There are locating dowels for the crank and if you don't seat these in the holes in the crank, you won't get the crank bolted back into place so just take your time and don't try and force things... they will go back in with some fumbling. After you do a few dozen crank reinstalls you fingers seem to get a feel for the locating dowels... Once the crank is bolted back in, take the time to chase the thread on the case bolt holes; blow the holes out with compressed air afterwards and clean the bolt threads and then toss the case back on and reinstall the bottom case bolts. Flip the engine over and reinstall the top 5 case bolts. I use liquid gasket maker UNDER all the bolt heads and Loctite BLUE on all the thread except those bolts INSIDE the engine and I use LOCTITE red on them with NO liquid gasket maker under the heads.
At this point, you are ready to stick the engine back into the bike. It is heavy but I just lift it into the frame ONTO a waiting transmission jack to balance and help locate the engine. The J motor has rubber mounts in the front so make sure those are in place before you start bolting stuff down. Do everything loose first and then snug it up. It often helps if you clean the thread on the bolts/nuts for the engine mounts before reinstalling. Also, you might want to take out your pickup coils before pulling the engine so you don't smoosh the wires... Also, the upper rear mount bracket that also holds the brake light switch is better just removed prior to pulling the engine to make some room and then put in AFTER you reinstall...
can't think of much more but don't be afraid to ask questions. Cheers
