Milling your head is the last thing i would do, to be honest.

whats your tire pressure at

 

Any fuel can pre-detonate if the conditions are right, and that's not just limited to compression, no matter the octane/cetane/whatever-ane level. I know what you mean though, one engine with no change in timing/compression/etc- the 93 will be less likely to detonate first.

I shouldn't have used the word thorough. I was referring to the "burn" vs. timing. Score one for you pimpin'.

The thoroughness of the burn is mostly based on propagation. In the Ruckus, 93 would burn more thorough but not as efficient...if that makes sense. Take this into consideration, the Ruckus has a compression ratio of 12.0-1 (I think the F.I. were 11.9-1), excellent compression for a higher octane fuel, but engine temps are low enough for detonation to NOT occur, thus making 87 a better candidate because it IS easier to ignite at lower temps . Imagine trying to run 87 in ..lets say..an s2000. It may actually run "ok" under cooler temps, but knock/ping like crazy when up to temp.

There's not a gasoline engine in the world that will run correctly and burn 99% of it's fuel. You need 5-10% more oxygen-to-gasoline to burn 100% of the gasoline set up in a combustion scenario, and that's only if conditions were ideal (no carbon/hydrogen/nitrogen mixed in with the oxygen). Conditions are even worse inside an engine because there's only a small window of time for the combustion to happen, the incoming air is never consistent, and neither is the gas. Did I mention gasoline isn't as pure as it should be? How 'bout the fact that oil is also introduced into the combustion chamber via the cylinder walls? Moisture in the air? I could go on and on...You would think in a LEAN scenario ALL the gasoline would be burnt, but really it isn't (on a molecular level).
Look up Stoichiometric Combustion (Theoretical combustion). It will mind fuck you.

 

Your biggest dis advantage is the fact that it's air cooled. These smaller air cooled engines are a SUPER sensitive to the environment. Milling the head down would increase compression and I bet it would run like a raped ape when it was cool out. Being that there isn't really an upgrade option for the ignition or head, I would try to steer clear... unless you were after a race-ped that you would only drive at certain times. Could you imagine sitting at a stop light on a hot day for any period of time then trying to drive off. The fucking JAWA will almost cut off on me in the summer.

 

I'm not sure I'm capable of properly milling the head... I was also thinking on a lesser scale of that I could try a thinner gasket but I don't know if that would make much difference. Could a better carb/airflow/exhaust combo with proper jetting and tuning provide me with a worthwhile gain?

 

very cool.

 

Of course man, depends on what you mean by better carb though. The mistake a lot of the 'ped guys make is too big a carb. Try not to go but so much bigger, but actually look for a QUALITY carb that has a lot of jetting options. A little inlet polishing, a good filter, and proper jetting will go a long way. Being that these engines are air cooled (sans fan) they are at the whim of every element in nature. Ever notice that it runs like a champ in the rain even if it's hot? The excess moisture in the air not only drops inlet temps but it helps DRASTICALLY with heat transfer from the cooling fins.

Try replicating with a spray bottle set to "mist". You'll be surprised.

The key with the exhaust (2 stroke) is to find a chamber that is easily adapted to your current header. The other thing is to "bone-up" on knowledge about how a chambered exhaust works. I could explain but 1) I'm a little rusty on the subject and 2) I've typed enough already. In short, it uses sound waves to "super charge" the cylinder via the exhaust port (helps compress the mixture inside the cylinder).

From a performance stand point, a chamber that's shorter in length/fatter in diameter and closer to the engine will perform better at lower RPM's, and a chamber that's longer/skinnier and farther away from the engine will perform better at higher RPM's. Considering just about everyone wants their performance "up top" (most of our riding is done at WOT), the "bi turbo" is a popular candidate because of the fact it's easily adapted and has a chamber made for higher end performance. The good thing with older 2 strokes is they were commonly equipped with what we consider a "traditional" baffled exhaust so ANY chambered exhaust will provide some sort of improvement.



Cool gif right? Walter Kaaden was a beast.

EDIT: The length of the "cone" (first part of the chamber) has a lot to do with how the chamber performs as well.

 

TLDR.

 

I'll cliff for you:

2 stroke is magic
Chambered exhaust = POWAH!!
Heath is French for "cum dumpster"

 

it all makes so much sense now...............

 

Fobangah- thanks for the insight as well as the sweet animation. I guess I have some decisions to make. A guy on MA is trying to put a puch e50 on his batavus.... I'd like to wait it out and see what trouble he runs into. If it's not too huge an undertaking I may try to go down that road as well. I really like the idea of the engine swap because parts of the batavus are belt driven with this tiny weak ass looking belt. And I'm afraid if I squeeze more out of the stock engine I run a higher risk of shredding up belts that I don't know where to find replacements for.