scorching on the crank?

[Adam Davis]

So I am at the beginning of a rebuild on my 2000 Blaster and was 50/50 about rebuilding the bottom end. After I took the cylinder off i noticed what looked like heat stress/scorching on the crank. this will be my first rebuild.... Super Noob status and am not sure if this discoloration is common. over all the bottom end seems tight.

 

[Blaaster]

The heat colouring is perfectly normal, it is made by the assembly process.

 

[Adam Davis]

How will I know when the crank needs to be replaced as well as the bearings?

 

[Blaaster]

See the above pic, those are the limits.

 

[Adam Davis]

See the above pic, those are the limits.

I'll have to bring my calipers home from work. thank you for the diagram Blaaster!!

 

[jus_me]

Feeler gauges would be best to measure the side to side play. Any up/down play you will need to replace or rebuild the crank.

 

[OConnor Racing]

Feeler gauge between the rod and the thrust washers. Anything over .028" is out of spec. KOR can rebuild the crankshaft and supply all of the necessary components to complete your rebuild. The factory crankshaft is the best. Rebuild it before spending money of Chinese parts.