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Question for the inmates - with RB no longer doing heads (all though there are others who still do) Do you think there would still be a demand for a replaceable dome head similar to the ones APEX makes for the YZ250? Or not worth my time to fool with it as the bike is that old now? Just thinking out loud here....

Too late, maybe back when it was still in production

KDXGarage wrote: 02:43 pm Jul 19 2024 Too late, maybe back when it was still in production

Kinda what I figured - Designing it costs me nothing. So may fool around and test fit 3D prints just for my own enjoyment.......

There's a thread on here from a year or two ago where a guy was talking to Phat Heads about doing a KDX version head. There were several people interested, but I don't think he ever followed through with it. Phat Head was encouraging and interested in making a batch, and said they'd do it with a minimum of 10 pre-orders.

In reality, we really just need another machinist who will modify the stock heads. The two-piece design introduces more areas with a chance of failure vs making the same profile by modifying a stock 1-piece head. Tom Morgan Racing or Pro Circuit or Ken O'Connor Racing can easily mod your head for tighter squish clearance, alter the squish band width changing the focus of the powerband in terms of high rpm peak power vs acstrong mid-range etc, and reshaping the chamber/dome for correcting the compression ratio after milling it to tighten the squish band clearance to a better more proper spec than most OEM bikes come with.

Can’t you send the head to fredette?

RB website still shows he does the head for $75.
https://www.rb-designs.com/rb_designs_llc_004.htm

A replaceable dome, would that require a switch to O rings rather than standard embossed gasket ?

All of the replaceable domes I've seen use o-rings.

Molly's 70 wrote: 03:45 am Nov 04 2024 All of the replaceable dome I've seen use o-rings.

I suspect this is because the removable dome will shift around significantly with thermal expansion and contraction as it's not rigidly connected to the rest of the head at the head gasket surface side.