Jump to content
Sign in to follow this  

Which Piston???????

Recommended Posts

I have a question. which piston is better or which do you guys prefer the pro-x piston or a weisco piston?

here is a link to the weisco one.....i kinda liked it better because it comes with the gaskets and it is higher compression but i wanted to get your guys' input first. is a higher compressing better or worse?

here is the link to the pro-x piston

Share this post


Link to post
Share on other sites

A number of people have reported broken aftermarket pistons on this board. I've used Wiseco's (big bores) on all three of my KX250F's and the've held up very well. The only negative is that they are heavy and I believe that is because they are forged. I use a lighter OEM flywheel to compensate for that. I am looking for a lighter cast piston that can handle at least six months of abuse...

Share this post


Link to post
Share on other sites
A number of people have reported broken aftermarket pistons on this board. I've used Wiseco's (big bores) on all three of my KX250F's and the've held up very well. The only negative is that they are heavy and I believe that is because they are forged. I use a lighter OEM flywheel to compensate for that. I am looking for a lighter cast piston that can handle at least six months of abuse...

A few Piston weights.

Forged OE is 141.4 grams

Forged OE replacment Wiseco is 141.3 grams

Forged High Comp Wiseco is 144.0 grams

Forged Heavy Duty high comp Wiseco 144.6, shot peened, skirt coated, brushed dome. None of these R734M07700 have ever broke.

Forged Pro-CIrcuit/JE custom is 175.2 grams. (wow what a boat anchor).

Forged custom Big Bore 81mm MaxPower/RPS KX250F 160.8 grams

Both Athena and Vetrex Big Bores are forgings.

Share this post


Link to post
Share on other sites

The Je piston 13.5:1 I got wieghts 147 grams STD size and new stronger design part number 243642.

Share this post


Link to post
Share on other sites

My bad... Thanks for clearing that up. I was comparing the stock piston weight with the big bore Wiseco. I guess since my bore is 10% bigger than stock I should expect that the piston be that much heavier also.

Share this post


Link to post
Share on other sites

I just checked some of my old pistons:

OEM piston ('06) 77mm = 146gm

Wiseco 79mm = 146gm

Wiseco 81mm = 162gm

The 79mm piston really surprised me. I expected it to be heavier. The 81mm is 11% heavier than 79mm but that is only a 5% increase in displacement. Does anyone out there have an Athena (290) piston they could weigh along with stock to compare these numbers to?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×