I have read before that some owners of '86 250Rs will put the longer rod in and use a spacer plate under the cylinder.

What is the advantage of this?

My machine uses the same rod as the '86 and I was wondering if the longer rod would do anything for me. I currently have my clutch set to engage at 4500 and the motor spins to 9000 so I am looking for mods that help top end.

 

There are a number of reasons why someone might use a longer rod in their 85 or 86 engine.

First of all cost. If their crank went out the cost of a new 86 from Service honda is $387.47 while an 87-89 crank with a longer rod is $215.26.

Another reason people use them is for smoothing out the powerband. By adding a spacerplate there is more crankcase volume.

The longer rod is supposed to create more low end power due to more leverage while the shorter rod setup tends to rev better.
ERIC

 

Thanks, smoother power is not what I am looking for.

 

It does that but i think it might still make a little more power all over because you are pushing down on the crank more than with the shorter one were it is pushing out a little more. but i do not think that would change much but it will rev faster because it is lighter. Pluse you get higher crank case compression with the short rod.

 

I`m not sure but I think the with the gaskets you can raise the port height. Thats what I`ve seen on sleds anyways.