230ccm - tableau courbe et puissance -> plus de 20hp

[macbig2k1]

Yes, it's done, I've finished my 230ccm engine after a much too long time.
The carb has a well setup, there is just a small hole from idle to less open thottle.

Now the technical details sorted from the inlet to the outlet:
- modified Airbox
- Mikuni VM28-418
- 200/225 cylinderhead
-> incl. cylinderhead optimisation with porting to 71mm and a bigger outlet
-> Webcam camshaft stage 3 incl. Valve Spring Kit With CrMo Retainers Beehive (Race)
- 225er cylinder
-> with 71mm piston from Wiseco, compression: 10,25:1
- 225 crankshaft (58mm stroke)
-> incl. 225 ballancer
- Akrapovic Racing exhaustsystem (complete system incl. headerpipe)
- 5 disk clutch (not std. at the 125ccm engine) with fitted pressureplate for springs froma 600ccm Yamaha engine

Here the results from the dyno (stronger as the feeling from my testrides):
Performance: 21,8 hp @ 8,091rpm
Torque: 20,9 Nm @ 6,643rpm

Here is the chart in comparison to a:
TW125 (+10,4 PS {+91%}/+12,9 Nm {+161%})
TW200 (+5,8 PS {+36%}/+4,9 Nm {+31%})


Click to zoom!

Here are the org. prints from the dyno:


Regards, Sebastian

[macbig2k1]

Is the the correct transalation?
-> tableau de couple & puisance <-
What would be a better headerline?

The VM28-418
Mainjet: 190
slowjet: 20 (will try a smaller for emission values)
Needle: 5L1
needlejet: P-4 (not 100% sure)

I don't have a "compressionmètre".
It's the wiseco piston for the YFM225:
Wiseco Part#: 4312M07100
Product Type: Single Pistons
Description: 71.00 YAMAHA YTM/YFM225 2795XC
Displacement:  226cc
Bore - Standard:  70.00mm
Bore - Actual:  71.00mm
Bore - Oversize:  1.00mm
Stroke:  58.00mm
Compression Ratio - Actual:  10.25:1
Note:  Cylinder boring required


I will measure this week the compression chamber to calculate the real compression -> not the barometric value.

[george-le-yeti]

Nice work, 21cv isn't so bad ! 

[macbig2k1]

Nice work, 21cv isn't so bad ! 

Not 21cv -> 22cv and 21Nm

[warnours]

Not 21cv -> 22cv and 21Nm

Wel done man !!

[nico-dem]

Wel done man !!

ça donne envie de modifier 

[JF26]

la , vous montez très haut !!!!

[macbig2k1]

gearing is 14/40 520 chain (17,5/50 in 428)
and the rear tire is 180/55-17

and I still use the tw125 gears.

[Sylvain]

Ca ressemble fort à ce que je devrais obtenir avec un piston 73mm et chemise de 225 monté sur ma TW200,Mais comme les rapports de boite ne sont pas les mêmes je me demande ce que ça va donner.
A vrai dire je ne croit pas aller beaucoup plus vite car j'ai l'impression que ma 200 prend déjà son régime maxi sur le dernier rapport.
Cela dit je m'en fout un peu car je cherche surtout à gagner de la pêche.

[macbig2k1]

Avec un piston 73mm...Tu vas avoir un

My engine or your engine???
I have this combination: 71 x 58mm (bore x stroke)

Sorry, I don't understand this table: