Wiseco pistons vs. stock

[1984 honda 200s]

Im just curious to see what you all say about Wiseco pistons.
Are thay known to be noisy?? I know when i run my 200s with a .20 200x piston in -10 weather it knocks for a good while between cold and warm then it goes away... Is this normal?
It has hi compression and tonnes of power. Still hauls ass with a 13 tooth front and a 40 rear, can actually do 3rd gear wheelies down the road with it !
I just need to know pros and cons and are thay known to be noisy over stock !

[just ben]

are you sure its not valve train noise? Aweak oil pump will have a hard time supplying oil to the head when cold but will supply plenty with warm oil. The only "noise" a piston could make is caused by "piston slap" which is cuased by a worn cylinder and or piston. It doesnt take long of a piston slapping before the skirt breaks off it

[1984 honda 200s]

The top end was completly redone, ive been running it for almost 3 months, its just warm up time in -10 or -15 weather when she makes a noise just before getting warm then it goes anyway.
Fresh bore with matching piston and rings, valves reseated and set. It runs so well and tons of power but its just warm up.... after 5 mins of running is knocks then goes away with about 10 mins or less of just ideling to warm it up. After that it sounds healthy no noise what so ever. I did at first get noise from the valves... they were set at .008...... untill i read the manual correctly...002!

[RIDE-RED 250r]

A "knocking" can also be attributed to detonation.. You say you are running the high compression piston. Might you be running slightly too low of octane fuel??

[1984 honda 200s]

Ive noticed that as well, i used to run just regular pump gas but noticed when taking off there was a pinging and it knocked way more on cold start.
Now ive switched to Supreme and noticed it knocks still on cold start but goes away after just about 10 mins of run time and doesnt ping at all during acceleration...
Could poor quality gas be my problem?
Just to throw this in'' the stock carb was making me idle bad, so i threw in a #38 pilot with stock #100 main... idles like a champ and burns clean''
Also running a CRF230F header with a 225DX cobra on the rear......

[RIDE-RED 250r]

Might want to give a 50/50 blend of 110 and 93 a try just for the heck of it. If premium fuel partially alleviated your problem it's very possible you may need to run premium with a mix of 110 to cure it all the way. It won't cost much to mix a couple gallons and give it a try. That way you'll know for sure.

What comp ratio piston do you have? If you have the 12.5:1 200x piston you are definitely out of range for premium pump gas if everything else in the topend is proper.

Your jetting adjustment you had to make is most likely due to your better header. Sounds about right. I don't know stock jetting for that machine off-hand.... Did you have to richer or leaner? I would suspect richer...

[jon jon]

i bought a weisco high compression piston for my 200x that im working on. buddy of mine has just a bore in his 200x and its faster than my 300ex so id say they work way better lol

[oscarmayer]

i always use weisco pistons every change I get over OEM. not jsut for the much better quality, but a ltitle extra kick doesn't hurt either. It's not the piston.

[1984 honda 200s]

It shouldnt be the piston, it has to be the fuel im using
Im unsure of the comp.... its a 20 over bore 200x wiseco... I'll check the box to see
And i had to richen it up ''bigger jet-bigger exhaust'' Jumped from a 35 pilot to a 38 and raised the needle up a notch.
So far i havent had any problems with it, its whicked fun now lots of pep.

[WilliamJ]

Something to consider when checking the compression ratio - the only way to be sure of your CR is to measure the combustion chamber volume including the gasket volume and piston dish or dome (dome will reduce the chamber volume) then add this to the swept volume of the cylinder making sure you take account of any rebore or stroker crank etc. Then divide this total by the total chamber volume to get your CR. If you don’t do this you will be guessing.

Bill

[200xman123]

what will happen if you run a 12:1 with supreme pump gas an a bit of octain boost

[oscarmayer]

no octaine boost. if you run 93, you need to run a larger jet and run rich or you'll ment the motor... (been there done that. i can now run 93 on my 200x because i run a fat setup and larger 26mm carb.

[200xman123]

Ok! What main jet do u sudjest I start at on my 85 200x to be able to run pump gas

[oscarmayer]

112 to sart and check the plug. maybe a 115

[1984 honda 200s]

I run the stock carb still with supreme pump gas, but i switched to a #38 pilot with a 100 main still.... its tan at wot.

[Dirtcrasher]

And unfortunately, many people guess.

Many people "trust" the shop to get the clearance correct.

The biggest deal with Wiseco is that they are forged, Or SMASHED?compressed into a mold of close proximity of it's intended size while the metal is still workable.

IMHO, that makes for a better piston with less molecules of air. Of course it must be machined down after forging but it is not "cast" or poured into a mold such as many OEM pistons which leaves allot of room for air.

[1984 honda 200s]

Well this guy i got mine done by is the ONLY guy that bores cylinders for a living...
I have no problem with mine, its been almost 4 months, the bike never sees a break, its ran everyday.
No oil used, no problems what so ever and im not the easyest person on it but i dont beat it to hell, im know for ''The Trike'' around here hahaha