thats a very nice piece for its age!.. . its probably tha easiest merc V6 ta work on and will live forever if taken care... even still has tha cle on it! if your boat is a lite weight it won't disappoint.. jus keep in mind that even though it comes from tha high performance side n all dolled up, its still justa 2.0 motor.. its about tha same performance wise as a 200 production motor...
not familiar with tha boat.. Austrailian/British, somewhere else???.. looks like its gonna be a fun (handful) ride???.. not much of a pad... ya may need ta bring ya "chine-walk" skills up ta date!
OK so managed to water test it again just now, still wont pick up in the water, as soon as its in the water and the offshore mid exhaust is under water it bogs. If its out of the water (trimmed up) it picks up under load. On the hose its no problem, revs crisp and clean on all six.
It looks like some kind of back pressure or water related issue. Updated list up things I've replaced and done below:
- Carbs stripped, cleaned and reassembled
- New OEM switch boxes
- New coils, leads and plugs
- Compression check (130 PSI all pots)
- New CDI Stator
- New CDI Pickup
- New Impeller and water pump
- External electric fuel pump has solid 6PSI on gauge
- Bypassed boat tank to outboard tank to alleviate that side
Any other ideas please, I'm all out, short of pulling the powerhead and looking at the water passages? Could someone who built this up, have used the wrong gasket on the powerhead to exhaust extension plate, causing these backpressure symptoms when in the water? I've never seen this engine run before (other than on the hose on collection)
Other symptoms it has no cooling water coming out of the pisser unless its revving (has new impeller and housing) - but there is stacks of water coming out of the prop hub.. All spark plugs are super clean, like brand new, even after running on the house for a few mins. Maybe steam from water getting somewhere it shouldn't is cleaning them?
