GX200 bearing size

[r_chez_08]

I may be opening a can of worms here, but why don't you just get another keyway cut on the opposite side of the shaft? (or do you want a 1" crank) Will the crank shaft not function correctly if this is done? Will the current damage weaken it in any way?

I am considering this. I do need a 1" crank but I cannot sleeve it to 1" because of the bearing. What I may dois fill in the damage with jb weld and cut a key on the other side.

What about just buying another crank ???

No, cos it is £40.

 

[r_chez_08]

I think I have to agree. There is a time to DIY-yer-butt-off, and a time to just "do the deed". I think this is one of those times you oughta check the duct tape at the door...

If we're going to take our hobby seriously, we have to do things the right way.

Maybe, but is this good enough
What I did:
1. Lathed damaged section of the crank to .500
2. made a sleeve .496 i/d x 20mm o/d
3. heated the sleeve red hot. Smacked it bloody hard onto the crank
4. filled in the key left on the crank with weld because it was damaged from the key rocking side to side
5. spent the past week cussing the above- the mig welding wire I used was very hard! I used an angle grinder, tipped tool on a lathe, a file and a toolpost grinder to get the weld down to size.
6. I now had a crank that was a fraction of a hair under 1"
7. I used an end mill and an "X" block with a 3/16" cutter to cut a new keyway, on the opposite side from the old one.

I have pics of the steps along the way if you want to see.

I am pleased with the end result. Aesthetically, it doesnt look that bad, and you can only just see the weld, and the edge of the sleeve. TBH though who gives a **** what it looks like, as long as it works! Only time will tell, but I think I may have saved my self £40.

I have recieved a new gasket kit and a flat top piston for the motor. Unfortunately it is for a gx160 with a slightly longer (3-4mm) skirt. How would I go about shortening it?

 

[Doc Sprocket]

Hey- Not bad!

 

[landuse]

hey- not bad!

x 2

 

[r_chez_08]

Cheers. I hope it holds up.

 

[r_chez_08]

I got a 160 flat top piston. the skirt was 4mm longer. I modified it

 

[vpd66]

I got a 160 flat top piston. the skirt was 4mm longer. I modified it

Check your piston pin height. If a gx160 is smaller then a gx200 and the bore is the same then there is a good chance that the stroke is shorter and the piston pin height is different. This should make your piston stick out of the bore at TDC.

 

[r_chez_08]

99% sure pin height is identical. It looks the same by eye. The stroke is shorter, caused by a different crankshaft.