[Robb]

ok, jus took apart my 450 that had a severe smoking problem. This piston, rings, wristpin and bored cylinder only have about 50 miles on them before it started getting noisey and smoking.
What do you guys make of the marks on the cylinder, the unusual wear on the wrist pin, and funny mark on the piston.
I have another cylinder with a fresh 25 over bore and new piston, rings and wristpin. IM hoping to jus put it together and be good to go.

 

[dirty4man]

looks like the engine got hot from the heat marks, maybe lack of oil, but I see oil running off the connecting rod in the picture. I dont know without putting my hands on it.

 

[Railroader]

QUOTE ("Robb":fizot328)

ok, jus took apart my 450 that had a severe smoking problem.

Have you ever tried Nicoderm?

 

[ClassA64]

From my experiance it looks like a clearance issue when the motor heats up. The rist pin getting tight in the top of the rod may generate enough heat to cause the piston to grow to big and tighten up in the bore?? It`s likely to tighten up in the bore on the skirt side of the piston first. Just my thoughts.

 

[The Doctor]

were the old rings scorched?
make sure you gap the new rings to the cylinder
Im sure honda specs are close.
I dont know on these motors if the pin is floating, bearing or pressed.
If it is pressed then you may want to change the rod if it got hot
if it got really hot there would be signs of bluing on the parts

 

[Robb]

QUOTE ("The Doctor":36k8wub7)

were the old rings scorched?
make sure you gap the new rings to the cylinder
Im sure honda specs are close.
I dont know on these motors if the pin is floating, bearing or pressed.
If it is pressed then you may want to change the rod if it got hot
if it got really hot there would be signs of bluing on the parts

The old rings looked good.
It is a floating pin.