Hitchcocks Forum

I decided that i am Not Going Past 10.5:1 MCR and i can't run that much more pipe boost either. ( it's gotta run safe from detonation on 90+ octane )

so stock cams and timing at 10.5, Polished chamber, crown, and ports;

and a Mono-Directional Crank Case Breather Mod, pull the starter motor, and see if i can adapt this to feed into the case :

https://www.amazon.com/Kesoto-Carbureto ... 30&sr=8-37

then bring out the hose size between the stock crank breather and the air box...like a bulkhead barb fitting in the air-box, and a larger threaded barb into the breather...

so strait kick and pinching ounces, minus starter, small LiFePO4, dropping the batt box and center-stand..

i saw the "starter motor block off plug" and i was wondering if Hitchcock's would consider making an adapter for that manifold and reed cage....That Would Reduce Crankcase Pumping Losses, and so make more power..

i don't have the RE 535 CGT yet, but i have my eye on one .... so i don't know exactly how well it would fit..

i don't know how well a filter this big would fit in the bike, on that manifold, but there are lots of sizes..

https://www.knfilters.com/62-1511-vent- ... r-breather

and once the outgoing stock breather air inertia gets up to speed;
the case will draw in primarily, to entirely, through the reed valves mounted over the starter hole...

i don't have the bike yet, like i said ..
but i can't think of any other + HP mod, that won't push the engine closer to detonation,
besides that; and the stiffer valve springs with lighter valve collars ( performance valve kit )

and you can run the performance valves on stock cams ...
what that does is reduce valve train inertia, and increases pressure on the lobes..

when a valve is closing, then, more energy goes back into the engine....the closer you get to floating, the more energy is lost..

Hitchcock's already has that one breather improvement for people who want to keep their electric start,

that reduces inertia,

but this would eliminate inertia, and reduce restriction..

the manifold, and reed block, are an OEM for the Yamaha PW50...it's a little kid's, low flow 50cc 2-stoke, dirt bike.

i have no doubt it will fit in space fine, and do the job..

And what are the proposed benefits of this then ?

it will reduce crankcase pumping losses ....

when the piston goes up, ( twice per 4-stroke cycle ) a relative vacuum forms in the case.

and when the piston goes down, ( twice per 4-stroke cycle ), a relative pressure forms in the case..

Not sure if I have this right but
Your trying to pressurise the inlet using a take of from the crankcase leading to a small carb?
If so why? The inlet will just gunk up with the oil vapor

I have probably got it all wrong.

Good luck with you're project Dai

Daiwiskers wrote: ↑

Mon Jan 31, 2022 7:49 pm

Not sure if I have this right but
Your trying to pressurise the inlet using a take of from the crankcase leading to a small carb?
If so why? The inlet will just gunk up with the oil vapor

I have probably got it all wrong.

Good luck with you're project Dai

your close, but have it all wrong at the same time..

as the stock breather goes, ( the out going breather ), i would open it up just a touch, and loosely stuff some copper scouring pad, ( like chore boy scouring pad ), material in the main part of the oil labyrinth...gravity in the tube will handle some of it, and any fine particulate will incinerate ... it won't be much residue, if any, and i am a fuel injection type..