Do I need to replace the crank pin when I replace the connecting rod bearing?

[thefox]

Do I need to replace the crank pin when I replace the connecting rod bearing? I have already replaced the crank bearings and have a new wiesco piston in a fresh bore.

[NICKG]

yes, the pin and the bearing are wear surfaces. the old bearing wears on he pin, if you put a new bearing on an old pin, you defeat the purpose of a new bearing...don't be cheap spend the 10

[Curtis-Tecate3]

Are you talking about the wrist pin at the small end of the con rod or the actual crank pin at the big end of the rod? You should always replace the wrist pin and bearing anytime you do the top end.

Curtis

[Billy Golightly]

Yes, you should.

[thefox]

Ok, thanks for the help.

I have already replaced the wrist pin along with the new piston. When I bought the trike the engine was in a box and in bad shape. After replacing the crank bearings, in bore and piston, and a good used head (reseated valves) I started it and heard a loud clanking noise, it sounds kind of like really loud valves. A talked with a mechanic at my local Yamaha shop he said that is was probably the conecting rod bearing.

I have already replaced the piston so it can't be that. I have checked the valves a few times but it is louder then they would be anyways. The crank bearings are new.

This machine just doesn't want to be finished, since when do the crank and rod bearings wear out on a four stroke anyways? This thing must have had a tuff life in the past.

oh and nickg, the pin is $17 and I am a poor college student :cry: , I don't want to replace perfectly good parts if I don't have too, but since it needs it then I will.