Rebuilt Mercury 300 Promax Drop on powerhead (Ported by Chaz)

**MaDneSS** · 08-04-2022, 05:21 AM

Freshly rebuild 300 Promax

Exhaust chest ported
Liners removed to gas flow all the transfers
once removed, liners were ported (exhaust, transfer and inlets) before refitting and port matching to block
Front half cut and counter bored to increase crankcase compression
Rod slots opened up and gas flowed
All oversize pistons 2xBrand new ones in the bottom, the rest were replaced less than 20 hours ago when the motor was first built.
Cylinder heads cut to 57cc which will hapily run on Pump fuel
Weight matched Rods (end to end balanced too)
Lightweight flywheel

Injector have been cleaned and are all within 2 CC's
New spark plugs, cleaned regulator screens, all bleed pipes replaced,
Reed cages have been linished perfectly flat and fitted with CCM Reeds
Never had any holes or welds in the block
300 Promax ECUs with 7000 rpm limiter

This is an awesome powerhead which owes me a small fortune. Its not seen fuel since being built so will require running in. I have loads of pictures of the machining and build process if you'd like to see how much work went into it.

Asking $5750 as a drop on powerhead ready to go

located in England but have shipped engines, boats, mids etc all over without problem