125-200cc is this true?

ive heard from a couple people now that your supposed to drill a hole in the front of your weisco piston on the 125/144 engines to help with the wear caused by the exhaust bridge.

anyone ever do this? is this why im hard on pistons? am i crazy? should i have used the search option a few more times?

I think I read about drilling the piston in the instruction sheet
that came with the weisco pistons. I didn't drill it though, I think
it was only applicable to specific years. I'll see if I have any of the
instructions laying around to clarify.

http://www.wiseco.com/PDFs/Manuals/MSeries.pdf

FYI The OEM 125 pistons come with 2 holes on the exhaust side, and the Fast By Ferracci GP piston I'm running has 4 lubrication holes on the exhaust side.

The new one I have in the box already has the holes, I assume the
one in the bike at this time likely has the holes too, being I had them
both at the time, I would have checked them after reading the
instructions.

way back in the old days of air cooled 2st. I had a YZ250 ported by an engine builder and he told me to drill a small hole in the piston right where the bridge is. He said that the exhaust bridge is a hot spot and a small hole will help get oil and fuel to the bridge to help cool it since on 2st the mixture feeds from the crankcase.

Yes, you are crazy.

well ther you go, looks like i should be drilling some holes.

They used to have the 4 hole FBF pistons on ebay for real, real cheap in FBF Store.hard to find as they were listed as "pistions" (must be some Italian code)

The last topend I did was a wiseco piston and I called my dealer/race friend Gerald at Upstate Cycle. Gerald said that was more important for the older engines way back in the 70's and 80's. I didn't do it but I will say I now need a topend. I don't keep exact hrs of my bike but it seems kinda short. Moral of the story, I'm trying to find a vertex piston now. If not vertex I'll go OEM but I won't use wiseco again. btw, I don't know if vertex or OEM has the holes drilled.

ive got an EG 144 so i have to use weisco

I had a 1980 YZ250 with a bridged exhaust port and had to drill the holes to make it live.

The Wiseco pistons for my Yami comes pre drilled. Its hard to see with the glare, but the holes are there

It's a very common practice. Esp. on forged pistons.
If the directions say do it, do it.
Been using Wiseco products for decades. Never had an issue with their stuff....ever.

It's a forged piston so warm it up good first before flogging it.

YES! You really need to drill your pistons on the exhaust bridge.

I do it to all pistons that are run with exhaust bridges.

Some times I'll do it like the 285 pistons in pix from PC, if I see a need.

Funny, My bike was a 1980 YZ250 too.