Kawi2strokes.com Forum

I was always of the opinion that the stock pistons, maybe even more on the H1, have too much taper from just under the ring land to the bottom edge of the skirt. But I never figured this out until recently. The H1 had so much piston rattle, even when you set the bore clearance as tight as you dared. I am guessing that Kawasaki were scared of siezures on their new 500 because of piston heat so tapered the pistons more, for more ring area clearance, and in hindsight, probably too much. The later triples didn't seem to make as much piston noise, possibly the taper was less on them. Did notice with a new engine they were quiet but if you revved them too soon on warmup, this made them start to rattle, probably beat the lightweight skirts down.
I have Wisecos in my H2B. my brother rebuilt it in the early '90s, I don't think Wossners were in existence then. It's not rattly though, but only has 500 miles on it now.

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1974 Kawasaki H2B 750, 1981 Yamaha XV750 Cafe, 1986 Kawasaki KDX200, 2003 Honda XR100, 2004 SDG140. 2006 Ninja 500R Turbo intercooled fuel injected.

It's a relative thing. I ran my H2 to 80,000 miles with a change of rings, and in the end it was just to see how far it would go. (We gave up!) It rattled pretty loud, but then I watched people get re-bores at 5,000 miles, change oil type, put in in-line filters, etc. etc. for no reason. Then I started with porting changes and Wiseco pistons, (dykes-ring type even), pipes, etc. and guess what...it ran great and rattled a bit. You've got an air-cooled 2 stroke with big, amplifying fins, you are going to hear it. Get a Suzuki 750 if you don't like rattles.

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"One day, your life will flash before your eyes. Make sure it's worth watching." : anon.

I have to agree, Rod. I have a lot more miles on my H2 with it rattling than with quiet pistons. Any you're my inspiration to worry about it even less than I used to.

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If it surges, that's normal, upshift.

"If it ain't broke, don't fix it..."

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"One day, your life will flash before your eyes. Make sure it's worth watching." : anon.

Interesting comments on the Wiseco pistons. I never heard of issues with them. I installed Wiseco in my GT380 back in the early 80's. Put a quite a bit of mileage on them, including racing at Bridgehampton and Loudon with AAMRR. The bike still ran great when I sold it last spring.

I put Wossners in my H2A last summer and had my machinist friend set the clearance at .002" like Tuner Dave suggested to me(and did the tune-up procedure also like Dave suggested)and it doesn't rattle or surge, it runs perfect. I have had a couple of my old pals ride it and they asked the same thing, "How come it doesn't surge and how does it run so dang strong"?, I just tell them it's because I listen to what Tuner Dave tells me.

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1969 H1, 1971 G3SSA, 1974 G5, 1973 H2A, 1975 S3A, 1975 H1F, 1973 Z1, 1988 HD FLTC, Captain America chopper, 2000 Excelsior Henderson, 1965 Bridgestone BS90

Nobody else does, they all know better because they tell me so, .005 is best because ALL their engines are "race tuned".

I can hear Dave crying from here!

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"One day, your life will flash before your eyes. Make sure it's worth watching." : anon.

Love to see the taper and cam profile on each piston brand.

My Wisecos from 1987 were straight taper as stated, from ring pack to skirt.
Cam was way smaller than bore radius.

Forgot exact amounts, but simple and cheap.

Skirt collapse as usual, just like the prior Wiseco pistons.
.
cliff

dat beterer?

I must not be very proud of these pistons to even spell them correctly thanx!

Ever try the dyke's ring style?

Try spelling 'Wiseco ' right, at least! I used 2 sets of Wiseco's back in the day to haul my H2 around, I didn't have issues with them. I'm sure Wossners are a fine product, but I bet they rattle after a while.

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"One day, your life will flash before your eyes. Make sure it's worth watching." : anon.