The Burning Question...?

[tacky1]

I seen the builder open up an RZ500 engine with Wiseco pistons. The Wiseco pistons can’t go the distance like Yamaha pistons. Tacky your Wiseco pistons lasted that long since you have various bikes and not ride the bikes with Wiseco pistons very often

Ride them all, dirtbikes get beat most weekends especially by my now grown up kids, 2 KTM 300s, 2 KTM 250s, 2 CR500AFs, 1 YZ250, all smokers with Wiseco pistons, hare scrambles, track, trails, pure solid abuse at 50:1 mix in the KTMs, 35:1 the rest.
I have 5 350s, 4 500s, 1 421 that run wisecos, Ive run them for years with zero fails......

Where did you get your "fail" info, They definitely take a little time to warm up.....
Did your "man crush" tell you they were bad

I see you turned this thread into another B.T. BS THREAD!!!!!!!
You cant help yourself, can ya,,, Its kinda unhealthy you know

[giron]

I have not mention Brian. Yet you guys keep
Bringing him up. You must not get any rest since you are constantly riding all these bikes.
Have any of you guys ever called him and spoken with him.
I see that you sold your RZ500 with the stage 3 built with Wiseco pistons. I read that it takes time to warm up. Can it be some piston slap

[silverstrom]

It's a forged piston problem. The pistons warm up easily. The problem is they warm up faster than the bore and if you are impatient you'll get a 4 corner seizure because the piston is now too big for the bore. Take some time to properly warm the engine and then proper bore to piston clearances are maintained. You must let the bore heat sufficiently to be successful using forged pistons. I have Wiseco pistons in my N2 and ride it hard and have never had any problems because I wait for the engine to properly warm up.

[tacky1]

I have not mention Brian. Yet you guys keep
Bringing him up. You must not get any rest since you are constantly riding all these bikes.
Have any of you guys ever called him and spoken with him.
I see that you sold your RZ500 with the stage 3 built with Wiseco pistons. I read that it takes time to warm up. Can it be some piston slap

Exactly. Wisecos are forged pistons. Work great if you know how to run them, they take a few miles to warm up. They slap around when cold.

[giron]

Why not use OEM Yamaha pistons. The same thing happen with the 911 engines. Folks were using 911 Arias pistons simply they were cheaper. It was a poor substitute for the OEM Mahle pistons. No substitute for OEM pistons

[tacky1]

Why not use OEM Yamaha pistons. The same thing happen with the 911 engines. Folks were using 911 Arias pistons simply they were cheaper. It was a poor substitute for the OEM Mahle pistons. No substitute for OEM pistons

The forged ones work better on high compression engines that use shite pump gas. They don’t melt.

[giron]

High compression pistons with shitty gas. That’s a recipe for a hand grenade. Every time you start the engine. You are pulling the pin and you don’t know when is going to go off. They said the same thing back in the seventies with Arias pistons with the 911 engines. No substitute for OEM Yamaha pistons and 911 Mahle pistons

[tacky1]

High compression pistons with shitty gas. That’s a recipe for a hand grenade. Every time you start the engine. You are pulling the pin and you don’t know when is going to go off. They said the same thing back in the seventies with Arias pistons with the 911 engines. No substitute for OEM Yamaha pistons and 911 Mahle pistons

Ok

[Jeff B]

I know everybody wants to get the last word in, but can we end this $hit storm and get back to "The Burning Question...? It's all been said before anyway.

[silverstrom]

Why not use OEM Yamaha pistons. The same thing happen with the 911 engines. Folks were using 911 Arias pistons simply they were cheaper. It was a poor substitute for the OEM Mahle pistons. No substitute for OEM pistons

The obvious answer is that isn't always possible because Yamaha only make pistons to fit two bore sizes larger, so up to +0.50 O/S maximum. If your bore is larger than 56.90 Yamaha pistons are not an option.

[giron]

What about an OEM piston from a different two stroke model from Yamaha. Time for a thinking cap

[tacky1]

What about an OEM piston from a different two stroke model from Yamaha. Time for a thinking cap

We used dt175 pistons years ago in 350s. Slightly higher compression. Perfect head squish without machining.
I don’t know of any for the 500s though

[giron]

I read on this site where there are OEM pistons for the 500 from another model

[silverstrom]

You can use first generation TZR250 pistons. Use for upper and lower cylinders. But again you are limited to max 0.50 O/S.

[giron]

John you should have said this earlier and saved all the time praising Wiseco. The OEM pistons no need for warming like the Wiseco