Tanaka 40cc upgrades

Local time
3:58 PM
Jan 25, 2008
Hiya folks,
I did a whole huge amount of work to my
40cc Tanaka because I couldn't deal with the power it put out,
too low for me. So it was modding time!

1. I filled in the channel inside the cases with JBweld,
2. made a small adapter to add a WYK-58 carb (15mm)
3. cut the bowl transfer "walls" Tanaka put in,
JBwelded (stuffed) the transfer bowls.
4. cut out some of the cylinder wall to open up the 2 extra transfers
(I wouldn't do this again if I were to replicate my work)
5. Cut a notch in the top of the piston to aid combustion,
and cut the sides of the piston for the transfers
6. lowered the cylinder, using no base gasket (just sealant)
7. Swapped the coil for an G23lh coil (no rev limiter)

These upgrades added a giant amount of power,
without being much more noisy or using that much more gas.

I was comparing the Tanaka to my Zenoah G43l in those pictures....
G43l is the motor on the right (but the piston shot it's on the left)


Jim H

Naw robot, truth is I'm too lazy to tax my brain with that much engineering stuff but thanks just the same.


New Member
Local time
2:58 PM
Mar 7, 2021
Just ask any questions you have.
I can explain it all pretty easily if you want to know more.
Ok u said that u cut out some cylinder wall to open transfers but wouldn’t do it if u had to do over. Why is that? And what’s a bowl transfer wall?
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