WOT speed on a '83 20' SF w/200

[Blue_Heron]

Hey, Spareparts. Thanks for the suggestions. I wanna touch on all your points, so this is gonna be a long post.

First, I'm not sure which factory timing spec to use on this motor. XR6? 200 carb? 200 EFI? (that's what the powerhead is). They range from about 18 deg to 26 depending on model year and the timing module they came with. I'm just looking for the maximum I can safely advance the timing with the module disconnected. One mechanic told me 21 degrees, another said 23

I rejetted the WMV-3 carbs with the same mains and backdraft vent jets called for in WMV-18s. I left the idle jets alone. It runs fine, in fact, there was no noticeable change in performance. I'm thinking the bigger mains give me a little safety margin on timing advance. Am I on the right track?

I'm not really trying to make a race boat outa this thing, just wanna get the full potential outa the engine I've got. Though it might be cool to get 50mph outa the thing, I don't go that fast very often. My skiff will hit mid fifties, but I usually cruise at 30-35.

Oil injection was not installed when this motor was thrown together. I'm thinking of adding it back. I have a complete system off a friend's merc V6. His ate the gear on the crank.

The Mirage props I've tried are numbers 48-13702-A40-21P and 48-13702-A41-21P. Not sure if either is a Mirage Plus. I've looked for a Laser II on Ebay and haven't found one that fits the large gearcase in the right pitch. Between the Seacraft and the flats skiff, I have quite a prop collection from my ebay shopping.

You're right about the hull running wet. I can't seem to get the bow out of the water even with a lot of trim angle. I was hoping someone on the board has a Seacraft Industries 20SF hull and we could compare notes. I suspect my hull is more bow-heavy than the Potter 20s. I don't have a t-top, so that's not slowing her down.

My flats skiff is an '87 Action Craft Flatsmaster with a '91 XR4. It's got a polling platform, hydraulic steering, hydraulic jackplate, fiberglass push pole, and trolling motor. It's old, but it goes just fine. It cost me about a quarter of what it would for a new rig set up with the same options.