Does anyone know if Yamaha got rid of that crappy rod they using in the 660 for the 700? Or are they re-using parts?

I was looking at my 660 failed rod. It is constructed of a very brittle material. No visible ductility what so ever in the breaks. That is the worst material to use in a connecting rod. It looks like it is cast instead of forged. I am thinking that the stock 660 was tuned to loose most of it power by 7500 RPM because yamaha knew the limitations of the rod.

Are there any other bikes that need a rod change when you hop them up?

 

Ive kept my 686 broken rod as a souvenier(expensive at that), mine let go right where the oil hole is at the little end. Usual place from what I have read[img]i/expressions/face-icon-small-disgusted.gif[/img]

 

Mine let go there too. It then split the rod down the middle for about an inch.

If it were a ductile material, you see elongation in the little hole. There wasn't any, indicating a brittle material. Connecting rods 101 basics says don't use brittle materials. It's frustrating.

I believe this 660 was designed for a rather tame street bike. Yamaha then stuck it in an ATV frame. This motor was just not tough enough to handle off-road applications. That's why they went to the 700. I am just wondering if they updated the rod.

 

The motor used in the new raptor is a completely different motor from the 660, it has been in use in Europe for some time now. It is probably not the same rod.

 

Was it used in Europe on street bikes? If so, it could still be a problem.

I guess no one has had it apart yet.

Does anyone have a shop or parts manual for that thing yet?

 

Completely different? Where do you think the 660 came from???

 

I bet they re-used a lot of internal parts.

The engine obviously has newer castings and a different head, but it still has the same basic geometry. The oil filter, water pump, stator, clutch, and transmission are all in the same place as the 660. I think the motor changes are mostly cosmetic.

I don't think it is "completely different".

 

I think I read somewhere that it uses a different rod but I may have been dreaming.[img]i/expressions/face-icon-small-cool.gif[/img]

 

tough

Why does the word tough automatically link to Polaris?

 

It's a advertising tool.