hi to all
i need to replace my cranckshaft on my 50 cc engine
is there any video to see and lern how to do it?
is it a must to change the the front and rear bearrings the engine is one year old only did not fly much at all
thanks

ilan

It really not all that hard to do but I don't have a video.
Start by removing all other parts from the crankcase assembly. Then set the assembly on its back on a drill press. Put a piece of 1/4" plywood under it to protect the metal. Then use the drill press to press down on the end of the crankshaft. You should be able to press the crankshaft right out. If its stubborn and hard to move heat the crankcase with a heat gun. If you don't have a drill press you can do this horizontally in a vise if you can get the jaws open far enough.
Hopefully the bearings will come out with the shaft. If not you will need to get a bearing puller.
You probably won't need to replace the bearings. Rotate them with your hand. If they are free and have no rough spots they are probably good

thanks for your answer
how do i open the prop shaft to release the crank there is is a big nut inside the prop hub

ilan

this helped me http://thenullsystems.blogspot.com/2...cc-engine.html

I dont understand what you have. A picture would help.

thanks for all your replay to me
here is the the best pic and how do get this set out of the front of the engine
thanks
ilan

You will need a deep well socket or a deep offset box end wrench to undo the nut then a gear puller to remove the hub. There is a key on the crankshaft that may come off with the hub. Do not loose the key.

Take a old prop and drill it to fit the engine, Drill out the center of the prop for the deep well socket. Mount it to the engine and use it to hold the prop hub and remove the prop hub bolt.

You can use the prop washer to remove the prop hub, Put a spacer between it and the front of the crank and tighten the 4 screws a little at a time and it will take off the prop hub, Just make sure not to bottom out the screws in the prop hub, one thing that makes the DLE prop hub hard to get off is it is not a taper fit and has a lot of some kind of lock tite on it.

Also if you have a prop jig that has the center taped for threads you can use it to remove the prop hub.

Milton

i did something similar, except i used an old aluminum landing gear

Please Help!!!!!!

i can't open this thing please how to opern it
thanks
ilan

You would need a extra deep well socket to fit the hext nut down in there deep. I don't know off hand what socket size is needed though.
Now you could fabricate one if you have access to a welder. You first figure out what socket size you need with a deep well socket. Then you weld on a short steel pipe to the socket and then another socket welded into the pipe end so you can use a wrench on it.

Here in the USA I used to look for a Snap On Tools or Mac's Tools dealer (they used to have mobile tool trucks go around and visit all the repair shops around town). Then order and or buy the special tool I needed from them. But I haven't seen a Snap On or MAc's tools truck van in a long time now. SUNEX for example makes a 1/2 inch impact driver extra deep well socket set, but it is a bit pricey, if you only need one socket out of the set. So fabricating one using the socket you can get more easily is probably the way to go.

the size is 13mm i do have the tool but it is hard to turn anticlockwise i think
ilan

Ok, you need something to lock or hold the prop hub adapter with then. Maybe a chain wrench would do it for you.
If you don't mind getting marks on the prop hub you could use a large vice grip or pipe wrench maybe too.
Some guys lock the crankshaft from the other side and then they can loosen the nut, but I tend to be reluctant to do that unless it is the only way. Some others use a piston locking tool inserted through the spark plug hole, but that has the risk of damaging the piston though.



The chain wrench Vice grips are pretty good for this too.