Namura vs wiseco

Yfs

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Jun 11, 2015
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which piston is better namura or wiseco? I have a 68.25 wiseco piston and I like it but I'm not sure if it's the best.
 
what kind of maintanance should be done on the piston?
 
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Wiesco's do require that you warm them up well before you work them hard.

Other than that, treat it as any other piston, feed it the correct amount of fuel and oil and keep the air that goes to it clean.
 
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How should I warm it up. Does riding it maybe in second gear not hard just a little driving work for a warm up?
 
Don't know if this is correct, but when starting cold I typically spend about 30-60 seconds, in neutral revving lightly, as it helps to spread the heat more evenly. Then when I take off I try to stay out of the band and avoid heavy engine loads for a few minutes, then I just ride normally, except I try to avoid long full throttle runs at least until I have been in and out of the power several times.

It may be overkill ,as I have read that for aircooled engines, a 60 second warmup should be enough to prevent a cold-seizure. But i figure there's not reason not to spend 5 minutes or so letting it warm up gradually it certainly won't hurt it.
 
Start the engine, regardless of what type of piston, and put your gear on while the engine is running. After you have your riding gear on go and ride.
 
Start the engine, regardless of what type of piston, and put your gear on while the engine is running. After you have your riding gear on go and ride.

I would take joeak47's word for it, if you browse the forum for a while especially some of the older posts, you will see that he really knows his stuff. He has probably forgot more than I know.
 
Seriously though... just warm it up. Give it a few moments to get some temperature before riding. more so for a forged piston. Let it warm up until its just hot enough to not put your hand on the cylinder head.
 
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Ok thanks. What do you think about Vforce4 reeds are they better than the boyesen rad valve?
 
What does porting do to a engine and how do you do it? And do the Vforce 4 reeds still use the stock intake boot? because I don't like the stock intake boots they crack a lot. The boyesen rad valves come with a less expensive and I would think better intake boot.
 
What does porting do to a engine and how do you do it? And do the Vforce 4 reeds still use the stock intake boot? because I don't like the stock intake boots they crack a lot. The boyesen rad valves come with a less expensive and I would think better intake boot.

Allows more air/fuel into engine. Depending on if ports are raised, it makes even more power, but at higher RPM, with some loss of power at lower rpms.
 
Once you take them out hold them up to the light and look straight through from the carb boot end if you can see more than a hair of light chances are they aren't sealing very good and can be flipped over once. A visual inspection of the reeds themselves looking for cracks or fraying can also show the need to replace them.
 
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Once you take them out hold them up to the light and look straight through from the carb boot end if you can see more than a hair of light chances are they aren't sealing very good and can be flipped over once. A visual inspection of the reeds themselves looking for cracks or fraying can also show the need to replace them.
So the petals can be flipped?
 
If your in a pinch you can flip them and get a little more, (maybe alot more), life out of them, I flipped mine and ran them that way until the new ones showed up.