1972 Trojan Tricabin

[dmatz]

I have a 1972 36' Tri cabin and am looking for answers to a couple of questions. The boat has twin 270 HP 350's and I believe it weighs about 16000lbs.. It had previously been in the ocean but now is located in Lake Erie. It had 3 blade 20x21 props on it. These would only let it attain 3200
rpm's max. I want to try different props to see if I can get to at least 4200
rpm's. Here is some info I have found out. I spoke to a couple of prop shops.I also did an online analysis on Michigan Propeller's site. The concensus is that it should have 20x15 3 blade props. These have been impossible to find. My question is,can anyone tell me what props most of these tri cabins have as original equipment? I have also been told that the 20x21 would be fine in the ocean and it rides differently in the water in inland lakes??? I have also removed the gen set it was inop. I am considering installing a inverter/charger. I am leaning toward a Xantrex 30-12. Has anyone made this conversion and what have you installed?
The boat has a/c.

[Steve H.]

The factory props for that boat is 20X21. I have a 1977 Tri-cabin with 270 hp-350 ci engines. My props are also 20X21. I cruise at 3000 rpm at 18 mph. My guess would be the problem is with your engines. I also boat on the west end of Lake Erie . Hom e port Leamington, Ontario.

[dmatz]

Steve Thanks for your reply. What are the max rpm's you run wide open? I also cruise between 2700 and 3000. My max rpm's are 3200 and a speed of around 24mph.(??by gps) I've had a couple of people tell me that this boat should run at a max of 4200 to 4400. This is why I been investigating prop sizes. I don't know of any engine problems, they seem to run great.

[Steve H.]

Dave: Sorry it took so long tp get back to you, but I wanted to get my owner's manual on the boat before I got back to you.
According to the 1977 Trojan Tri-cabin owner's manual, your props should be 20x21. Your rpms should be as follows:
@2500rpm 14.8 mph
@3000 rpm 21.7 mph
wide open throttle is 4000 rpm @27.6mph
I find my rpm's are close to those in the manual, however my performance is slowed by 2-3mph if my binini is up.
Hope this helps you.

[Michael Bost]

The factory props for that boat is 20X21. I have a 1977 Tri-cabin with 270 hp-350 ci engines. My props are also 20X21. I cruise at 3000 rpm at 18 mph. My guess would be the problem is with your engines. I also boat on the west end of Lake Erie . Hom e port Leamington, Ontario.

Steve: I am new at this(posting), I need to know how to get my prop off. The rudder is in the way of a puller, the shaft end is about 1/2 gone but will thread the nuts, they came off easily; I basically don't really know how but want to do it myself. The prop has a 1/2" x 3/4" gash in one blade. My Trojan has an original transmission and shaft(1972 30' Express, 2001 Crusader engine. Thanks for any help.