What is the highest compression any of you have gone ? With stock bore to 97 mm. Just wondering what some of the compression ratio is you all have tried.

Some cam timing is possible by fiddling with the spline choices. Ask Armen.

The point was, the answer is more complicated than the question. Simply asking what CR was used without taking into account other mods is not going to yield a good answer.

Overanalyzing?
Hmm, combustion chamber mods don't count? Then I guess you wouldn't want to ask cam people are using
After all, a long duration cam would give lower compression at lower revs.

zx-11 , and a stock cam would increase torque, if advanced, at lower rpm due to early opening of the intake valve ,and earlier closing of the exhaust valve ,which causes less revision .( but you knew that!)

Christof13T wrote on 01/26/18 at 14:30:42:


OK so no 13.5.1 out there lol

Be the first.
We would all be happy with a kick starter, too.

GT61 TURBO ZX14 wrote on 01/26/18 at 14:44:01:


Because as many of us have already tried to get through to you...
The cost and aggravation will NEVER yield the results to justify it.
It is a single cylinder, air cooled, mass produced for the best affordability/reliability platform. Not in any way, shape, or fashion an adrenalin junky's fix.

It was never intended to be a horsepower maker.
Come on man...
These things put out under 30 horses stock.

What you are proposing is basically pouring thousands of dollars and hundreds of hours in design into a platform that can be picked up for a few hundred bucks.

That's like spending 20k$ on a 1k$ honda civic, building up so you can keep up with stock muckstains...

It's clown shoes.

for most of us... money actually means something.
Keeping the bills paid...
Things like eating once in a while are nice...

I just went through the motions to swap mine over to the 95mm high compression setup...
My bike had just under 4k miles on it when I brought it home...
It is a 2006.
I gave literally 450$ worth of labor for it.
I was able to justify the 650-700$ or so that my build totaled.
But it was only because the oem configuration failed on me and parts replacement was necessary. For what the bike cost me, and the parts... It was worth it for me to salvage the bike. It would never make sense to me to go any farther with performance modifications.

Seriously man...
If you have been on one of these above 80mph... You would not want to go much faster. The front end gets kinda squirrely.

Like others have said... It's your bike... Your build... Your dollar.
But to be honest... The questions you are asking lead me to believe less of your technical capabilities. Someone ready to stroke out one of these motors, and hit it with laughing gas... Should not be asking about compression ratios, bobber kits, or any other remedial mechanical discipline. You are entering big boy territory.

I'm not making an attempt to talk down from a pedestal man...
Just trying to reel you back in closer to reality.
These bikes have been around and pretty much unchanged since 1986.
If it could have been reasonably done... It would have been by now - 32 years later.