Kawi2strokes.com Forum

No pissing contest.... I just get a kick out of the Denco specs, as they are mostly made up. And I specifically asked Tony about the measurements, and if the deck height was included, he said no. Maybe he got it wrong, maybe they did some and maybe not others. Plus the ambiguity with accessories. You want a 70 crank HP 500, add a set of pipes and you are close. Other numbers are off, they use the old tech staggered transfers and a lot of other stuff.

Fun to read, but nothing I would use to actually port a motor these days.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

uh oh... dangit.














j/k

All I was really looking at is the fact that some of the lower "stage" porting specs are just raising the exhaust a couple of mm and maybe a couple on the skirt. I can do (and have done) that myself. I'm basically using the Denco specs as a yardstick to do some light tweaking and be able to compare (by measurement) that what I'm doing has shown to be an improvement over stock. I know there are big improvements in 2-stroke technology but what I'm looking at doing is not so major that it couldn't be cleaned up by a professional job of the next stage!

S3 BTW

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We don't need no stinkin' Cams!

You can doodle around with a couple of mm on the exhaust and piston and make some hp. It's when you go farther that things really need to go by spec.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

For those who might be interested, I have created a spreadsheet with stock porting specs for H1, H2, & S3 with a piston position calculator at http://kawatriple.com/pistonposition.xlsx

It is interesting to note that the specs given in Kaw workshop manuals have specs shown in measurements from cylinder deck and piston position for crank angles place piston TDC at 1.5mm below deck for H1 & S3 while it is 0.5mm for H2.

The piston position calculator in the spreadsheet can also be used to determine piston position for timing advance for a given crank angle.

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Answers are here: http://kawatriple.com/

Thanks Dale, that's a great tool! And of course the S3 column works for S2 and S1 too since the crank is the same. Would need to verify the piston to deck offset on S2 and S1 for porting specs, but for iggy timing it's the same!

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We don't need no stinkin' Cams!

Thanks Dave

"See that hole right there, I made it real big"

Redneck Porting Advice

Old post but still relevant.

Denco may have been based on degrees ONLY.

If so, that is what really matters. Deck hgt. or measuring from said deck gives a relative position measure of the ports to each other, PERIOD.

Deck in my book is piston edge to cyl. top for squish.
Others' book may differ. on what the "deck" is.

Comp. ratio/intake events are different due to cylinder hgt. and case deck hgt. from crank CL.

cliff