Quote Originally Posted by jape View Post
Don't forget it is all very well getting a larger exhaust expansion, but you will probably need inlet side, i.e. carbie jet or injector change to match it and to be sure the fuel filter doesn't restrict and the spark matches if you really want extra 'ooomph'!
Jape, though I've not added the oversized pipe between my manifold and Laser exhaust, I did not make any changes to the injection system. Nor did the guys in Beijing who are adding the oversized pipe between the manifold and the stock bazooka.

It should be noted here that the Jialing's fuel injection system is from Bosch, and Jialing has promised a Bosch-provided upgrade to the software/firmware in October, which will address some issues, including some throttle hesitation in some circumstances. The upgrade will be provided to any JH600 owner who wants it. I discussed the implications of this upgrade with Zhang Haitao in Beijing, and he assured me -- on the basis of what specific knowledge I do not know -- that the Bosch ECU upgrade will not be affected by the oversized pipe, regardless of whether it's used with the stock bazooka or other aftermarket can.

Your view of this question does sound to be based on specific knowledge, and I have heard of this concept of "tuning" the electronic fuel injection system on some bikes. I don't know what is possible with the Bosch system. Can you cite any public references?

thanks!