I have been racing my 92 NF4 against my teammates 04 NX4 in the winter rounds at chuckwalla valley race way and as you can imagine, I'm a little behind in the power department. Here are a few updates on the second engine I'm putting together using a few more modern pieces to make the power gap a little bit less of a hurdle. The core in terms of power development for this engine are thanks to the JHA A-kit six stud cylinder from an NX4 model. With a little machine work this cylinder fits with out a need to modify any thing internally.
The front studs are the same on all of the RS125's the rear studs were updated with the 98+ engine cases and so the cylinder needed to be machined a few mm's to allow fitment. I am in some what of a hurry to get a pipe built for this heads port timing so they have not yet been counter sunk with a shoulder. I dropped the NF4 off with the old engine and new head to a company called CPI pipes to design and build the new pipe today. They said they should have the pipe built by the end of the week so I can finish the machine work on the cylinder. The cases are currently being ported and filled along with cutting the new ignition system woodruf key way. I have had a few issues with the stock units so I ordered the full kit from HPI ignitions. This should really help squeeze the last bit of power from this engine set up.
Last few shots of the new JHA/VHM set up in the older chassis
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