Squish band grooves

[motopsycho87]

I dunno, but to me it feels like the best thing I've done to my bike so far. And im a skeptic on most things! Feels like the power band bark before the valve opens now, and the over rev is actually higher than at 11.5:1 and 13:6:1. I'm sold.

[pscook]

Originally Posted by motopsycho87

I dunno, but to me it feels like the best thing I've done to my bike so far. And im a skeptic on most things! Feels like the power band bark before the valve opens now, and the over rev is actually higher than at 11.5:1 and 13:6:1. I'm sold.

All that you did was add the grooves? Squish was already adjusted and you didn't do any modifications to the current squish?

[motopsycho87]

Precisely. Total head volume has obviously decreased with it, but that is all. Squish was already at 1.1mm

[Zman]

You can easily reduce your compression by increasing the base gasket thickness. Another even easier option is to reduce your ignition timing which you can do in about pi minutes.

[risk74]

The only way to truly quantify results is on a dyno. Same dyno, back to back runs without and with new parts. Seat of the pants impression means nothing. Placebo effect, variations in temperature, humidity, fuel, rider's mental state make it impossible to get any definitive results.

[motopsycho87]

Oh yeah I know that. But I do ride the bike regularly, and temperatures have been pretty stable at around 5 degrees. The fact low down power feels increased with a lower compression says something. Fund the dyno rums for me and I'll do it.

[risk74]

Originally Posted by motopsycho87

Oh yeah I know that. But I do ride the bike regularly, and temperatures have been pretty stable at around 5 degrees. The fact low down power feels increased with a lower compression says something. Fund the dyno rums for me and I'll do it.

Can't do that, can't even afford to get my race bikes on the dyno. I like to think I am pretty in tune with the bikes too, I know I felt a difference going from stock head to a cut one. Want to believe I felt something with the large volume powervalve cover, but not sure.

[motopsycho87]

There is a dyno close that does a "no appointment" day, each run is ?25 so could do one with this head and my 12:1 normal cut head with SM wheels on... More concerned with just riding it atm, the trip to work and back was awesome!

[(F5)]

I've spent a lot of time on the dyno (I have a tame one I can use myself) and the amount of times I've made cool changes and then tested them to find worse results that often I couldn't tell riding it.

I became quite proficient and could probably write a book on the best 40 ways to detune your 2 stroke. I came to dread dyno nights. But those special times when what you did worked were good. For some reason I'd always send other people away with decent improvements when I helped them, but my own bikes fought the hard fight. They were however usually the fastest in class.

A harsh mistress.

[motopsycho87]

I'd be very surprised if the bike is producing less power, it starts and runs better than it ever has, considering I've tried 11.45:1 13.6:1 and now this at 12:1 having done a replate and bottom end rebuild before trying all. I ride my bike a hell of a lot, and like you have found many things that are supposed to give power actually bitterly disappoint, normally with an associated price tag! This however, besides jetting properly, has stunned me