AMGRacer

Just wondering whether other people get crankshaft wear similar to the following:



My piston and sleeve is fine no sign of wear there and the engine is perfectly clean otherwise. Just some scuffing around this area. All of my engines have a similar thing on them.

me43

have you ever overheated your engine or leaned it out to much?

AMGRacer

Nope just broken it in and run it normally, never over around 250. The marks are not scratches as such they are more like scuffing.

me43

what kind of engine, and what kind of fuel?

chuck h

The scoring that you see is from dirt..... check your front bearing also...........

AMGRacer

That was my initial thinking too. However the bearings and the piston and sleeve are in perfect condition. Same with my other 4 motors. The marks are not as bad as in that picture, that is not actually my motor in the picture. They are actually similar to metal on metal rubbing marks.

I have never noticed them before, not sure whether others get similar wear patterns.

AMGRacer

Rody 5 port motor with RB concept fuel.

me43

hmm.... have you ever over reved the engine?

AMGRacer

Nope it is still running rich from breakin. Have not leaned it yet.

me43

ooo, well i guess if you havent been having any problems so far then it should be fine, just remember to put after run oil

AMGRacer

Yeah I was more wondering whether you have noticed similar things on your crankshaft. I am not particularly worried about it.

me43

it might be just the way they mill it

compuatic

AMG, i just took apart a 21 with over 2 gallons in it for some major cleaning and havent noticed anything like this. Ive taken apart several engines in the past and havent seen this before. by the way, if something like dirt or shavings exists in your crankcase it doesnt have to neccessarly enter the with the fuel flow to your piston conmustion area but just hang around below your piston and thus you dont see scaring on the piston/sleve. just brainstorming. interesting indeed.

SHARP

Where in QLD do you get RB fuel? Is it this? http://www.rbproducts.com/rbww/fuel.html

Brett

the inlet that the carbie fits in may have had a bit of a bur or somthing at the base and it was scrubbin on the crank ?????