Trojan Boat Forum

I have a 1976 F28 that I cannot get to plane. When I purchased the boat a few years ago it would go past 2800 RPMs. With an almost empty boat I could get around 16 knots but the motors were always straining like I was pushing a brick wall and she would not plane. At that time it had 14 X 10 props. I installed 13 X 9 props and I can get to about 3400 RPMs at 13 knots but I am burning 13 GPH per side and still not able to plane. At 2600 RPMs I can cruise at 8-10 knots burning 6-8 GPH per side.
It has twin 233 Mercs(351 Fords)with Rochester 2 barrel carbs. Velvet 1:1 V transmissions. 350 hours on one engine and 400 on the other. I have heard that these boats should cruise at 20 knots and max out at 28 knots. Some folks have suggested switching to 4 barrels. Does anyone agree that upgrading to 4 barrels would help or am I looking in the wrong direction? Any suggestions would be greatly appreciated.

Does your boat have trim tabs on it to help it plain out faster

Is the bottom clean? A fouled bottom and running gear will knock you right down to nothing.

The boat has tabs, in fact the previous owner added a plate to each tab to increase the overall size of the tab. I have tested the tabs several times and they extend and retract the full length. The bottom is clean, I have the same issue after launching in the spring with a fresh coat of bottom paint.

Thanks

Something is very wrong with your boat and or engines. you should have no proplem geting to the mid 20s and turning 3800-4200 rpm . are both engines having troulble turning up to right rpm ? I would think you would have no proplem turning the 14X10 props .

Clean bottom was most likely, but now it sounds like your engines are getting tired ... check engine timing, plugs, etc., and go back to at least a 14x10 - you should be able to turn a 14x12 or more if its running right ... What RPM do you get on each engine at WOT?

If timing & plugs look good, comrpession check would be a relatively easy step (watch for sparks!). Plug wires are easy to replace as well - they don't last long in a marine environment.

I had the same issue a few years ago with a Chris Craft 283 with twin GM 283 V8s (rated at 185 hp ea when new) pushing 1:1 velvet drives and about 9100 lbs dry weight (I think similar to your Trojan). After replacing plugs, wires, cap, rotor I decided it must be the carbs. I spent some good $s on having the carbs rebuilt, bigger trim tabs. Check the compression, perfect. Then one day while on a short cruise at 8MPH, I rembered the last part of the ignition system, the coils! Replace both, and tada! On 14 x 10 wheels, I could suddenly run 19-22 MPH at 3800 RPM depending on how much fuel / beer / friends were on boat.

Don't forget to replace the coils... I guess mine allowed enough spark to run, but not enough when under a load to fully ignite the gas.

LandVF36,
Where in Minnesota do you have your boat? I'm in southern MN but keep our boat in the Apostle Islands, WI.
Jim

We keep the boat on the Mississippi at Red Wing. We live in Prior Lake. We have a smaller trailered boat that we take up to Bayfield once a year, normally late July / Early August.
Mitch

Thanks everyone for the advice. I definitely have a few things to check come springtime.