Finnsport 500, Mercury 220XRi

[Manuski]

Hello!

Finnish build "speedboat". I made new transom to the boat and removed the splashwell also. Some minor fiberglass work made also.
The boat is made in 1977, so its pretty oldie but goldie!
Hull itself weights about 220kgs.

Mercury 220XRi turning about 5800rpm right know with 27" trophy plus. Im getting more rpm out of it very soon (hopefully). :)

Top speed at the moment is 64-65 knots, about 74mph. Trying to make this boat go 70-75knots.

[Merc 2.5]

Low water pick up and raise it up on jackplate , will gain speed and rpm to maybe 6000k.

[Manuski]

Low water pick up and raise it up on jackplate , will gain speed and rpm to maybe 6000k.

Yes there is jackplate and low water pickup. Prop axel just above bottom.Turned near 6k at 66knots when I removed the black boxes.

I still need to fine tune timing and tpi. Timing now 24btdc but it seems to lose some speed when wot. Maybe i need to go 22-23btdc at the timing after cheking that tpi gives correct value.

[Manuski]

Tried few weeks ago 32" signature prop. 4-blade pro et copy. Skeg is original (risky), also I dont have nosecone so it limits the speed. 68 knots=78 mph, at 5500-5600rpm. There is alot of slippage, so i think original gearcase is breaking the water and causing the slippage.