ESE's works engine tuner

[_____]

[
Get yourself a decent carb
[COLOR=#ffffff][FONT=Verdana]if moneys tight.A Keihin PWK38S (short body w/Power Jet)

[COLOR=#ffffff][FONT=Verdana]of a KX250 the electric solenoid and tps arround 2001.
Ask Wobbly about the rest he has given out the details on how to mod the mx carb.

+1 on that topic!

[husaberg]

In 2002 or 2003 Honda on Cr 125 use biggest reed cage with smallest 28 mm insert, but carb is 38 mm.
2004 they return to std. smaller six reed cage type and normal insert. Maybe with big reed cage they lost speed in midrange and try compensate with smaller insert.
Very interesting, maybe someone know about this and had experience with that time Honda Cr 125 engine

No idea but this covers some of the changes
http://www.eric-gorr.com/files/pdfs/...s_honda_cr.pdf

One big issue with all the MX engines is that the carb is severely angled ( in both planes ) and this gives hugely asymmetric flow thru the petals.

Thus technically the reed blocks are way too big, but due to this flow limitation,in reality the situation is very complex.
I can pick up 4 Hp ( in 36 ) from a SKUSA CR125 simply by changing the petals and backups, to help even out the flow pattern into the case.
If we were allowed a straight manifold off say the RS125, then another 2 Hp is gained instantly,then another 2 with petals to suit that setup.
So going from 36Hp to 40 then to 44 just by changing the petals and manifold.

Romeau, what you are showing will never work.

The whole idea is to reduce the duct volume, so to have a round duct, that then reduces is backwards thinking.
The best RS125 cylinder I have tested had a 32 by 41mm oval shape at the cylinder duct exit.
This then transitioned from that oval to a 41mm header entry.
38mm is plenty for any RS125 cylinder,as I can get 48.8 Hp ( sprocket ) from a TM with a 30mm carb.
The very best RS125 dyno I have seen was 47 HP - rear wheel, this being a PV factory setup as used by Itoh.
That had a stock 38mm SPJ carb, and that translates to close to 50 Hp sprocket.
The reeds in a RS125 are nowhere near as clever as those we use in the TM kart engine,I suggest you start looking there.

Thanks Frits.

This spillover flow out the sides is very apparent when using the style of stuffer as is used in KZ engines.
I discovered this when velocity testing the flow of the SKUSA CR125 reed cage.
As the carb is offset upwards and also angled to the side there is a huge amount of extra flow on the right side petal exits.
There is a higher velocity out sideways than directly in line.
I adjusted the petal backup stiffeners to even out the differences, and picked up over 2 Hp thru nearly the whole powerband.
The only other comment I would have is that a big taper out into the transfer ducts as is shown in the RH pic does not seem to work.
Keeping the area in front of the reed box as small as is possible ( by reducing especially the vertical height ) seems to be better.
I think that making a real effort to fill in the roof and floor, then making extra area to the sides, to help the angled reed cage flow would be the go.
But in KZ we cant add material.

[EssexNick]

No problems for me. I'm viewing white text on a black background. Maybe try highlighting the text.

[Frits Overmars]

No idea but this covers some of the changes
http://www.eric-gorr.com/files/pdfs/...s_honda_cr.pdf

Husa, lately the quotes in your posts on the Kiwibiker and Oddbal forums are almost illegible:

Funny thing: there's nothing wrong with your posts on the Bucket-Foundry forum.

[Grumph]

No problem with Husa's quotes here, Frits - but your text has faded....

Who's been doing programme updates...

[husaberg]

Husa, lately the quotes in your posts on the Kiwibiker and Oddbal forums are almost illegible:

Funny thing: there's nothing wrong with your posts on the Bucket-Foundry forum.

Frits you need to cross to the dark side.
Bottom right of page you are currently set to light universe.
I have no idea why its doing it but i have noticed as well esp with multiquotes.
There is a quote above at the top of the page that includes a text and font code that is not in my origional quote?

[katinas]

Filming today
https://www.youtube.com/watch?v=5hOrPZ5AEgc

[Lbracing]

Hi everyone !

First of , you guys really do some amazing work and post incredible quality content , thank you for that .

Second , I have been making my own cylinder from billet for a while but its very time consuming so I want to get some cast ( 10 cylinders ) .
I am looking for someone with the ability to cast them , I can get away with the machining . Any help on this would be very appreciated !

These cylinders are 140cc with rsa style transfers ans exhaust without any cooling system ( run time of under 5 second for chainsaw racing) .

[Norman]

Hi everyone !

First of , you guys really do some amazing work and post incredible quality content , thank you for that .

Second , I have been making my own cylinder from billet for a while but its very time consuming so I want to get some cast ( 10 cylinders ) .
I am looking for someone with the ability to cast them , I can get away with the machining . Any help on this would be very appreciated !

These cylinders are 140cc with rsa style transfers ans exhaust without any cooling system ( run time of under 5 second for chainsaw racing) .

You can check out the company www.formkon.dk. They have for one of their customers casted such type cylinders ("rsa copies") using plastercasting (hm, is that the name for it?). I have been in contact with them for other things but I had the chance to look at one of them cylinders and it looked very good! On their homepage you can find a picture. It was not that expensive as I remember, you can always ask for a qoute.

[wobbly]

Formkon cast the cylinders for PVP Superkart 250cc twin engines direct off the CAD files - very good quality.

[Muhr]

You can check out the company www.formkon.dk. They have for one of their customers casted such type cylinders ("rsa copies") using plastercasting (hm, is that the name for it?). I have been in contact with them for other things but I had the chance to look at one of them cylinders and it looked very good! On their homepage you can find a picture. It was not that expensive as I remember, you can always ask for a qoute.

They are very helpful!
Nothing seemed to be a problem.

[2T Institute]

http://www.tz250.com/forums/showthre...A-kit-cylinder

but it can be made to fit rather easily it seems. see link above.
But you might be far better off with a 04 PV CR125 cylinder.

the result

[breezy]

Filming today
https://www.youtube.com/watch?v=5hOrPZ5AEgc

will be very interesting if this engine, you must give it a name..., does the same under load. im still not quite sure how the set up is even with pictures. is the crankcase still isolated from the cylinder barrel?

[Muhr]

Soon I hope all simulation work will be done! Waiting for cylinder deformation on heating and tightened cylinder head.

Not the best look, but hope it works

Engine for dyno testing the cylinder

[SwePatrick]

Engine for dyno testing the cylinder

If i had free hands to alter some small things.
This is from my mind only, no calculations at all. =)
Look carefully, there are a couple of changes.