Gaspar,
I found my engine (MW54) would only get to about 145,000 or 150,000 rpm with a 4 cell nicad pack. Thats why I went to a 5 cell pack, then it was too much and my ecu light would flash and the display showed only 25% or so pump voltage. Thats why I used a mechanical bypass and it works well. Not as easy if you cannot machine your own (can you buy them even?) but for me it worked well.

In my JDE instruction sheet it does say to use a bypass. Also says use a 2 cell pack ?? my engine would only run up to 100,000 rpm with 2.4V

Andrew

PS I use hausel pump