Trojan Boat Forum

I have a 1975 36' Tri-Cabin. It has Twin Mercruiser 255HP 350cid engines.

Does anyone have any specs on these engines such as WOT RPM and if present the REV limiter (Redline)? I have search the internet and found 4200 WOT and 4500 MAX. I figured someone here would know for sure on a 255HP 350cid Merc.

The reason i ask is that i have props that are too large on the boat. Right now i only get ~3600 WOT which i feel is a little hard on the engines. I had the unfortunate luck of hitting a submerged log in the channel over the holiday, the props are being re-worked. I'm going to have them knock a couple degrees of pitch off to bring up the RPM a bit.

Thanks much.

Aaron.

If I remember correctly the max rpm is 4000-4400 they gave a pretty wide range , the 255 hp was a 351 (ford) not a 350 (chevy) The chevy would be 260 hp 4200-4600 rpm ,

I have the same engines in my '79 tri-cabin and the owner's manual lists all of that information. Mine is aboard the boat and I will not be there until next weekend. I can send you the info then if you can wait. I can also scan that information and email it to you if you like.

k9th wrote:I have the same engines in my '79 tri-cabin and the owner's manual lists all of that information. Mine is aboard the boat and I will not be there until next weekend. I can send you the info then if you can wait. I can also scan that information and email it to you if you like.

That would be great. I do see now they are 351's sorry, typo there. I didn't get anything related to the engines from the previous owner.

Thanks much!

If you want a copy of my entire owner's manual I will scan it for you and email it. It will be in pdf format.

Where in the Chicago area are you docked? I get over there from time-to-time.

My marine power book says the 351 max rpm is 4400 rpm so I would prop it to around 4200

k9th wrote:If you want a copy of my entire owner's manual I will scan it for you and email it. It will be in pdf format.

Where in the Chicago area are you docked? I get over there from time-to-time.

I live in Chicago, dock the boat out with with other family members in Curtice Ohio, Anchor Point Marina.

Thanks so much, i look forward to the data coming my way.

Also thanks for the Max RPM info Prowlerfish, i was thinking 4000-4200 was a good spot.

My Trojan manual states 4,000 rpm is max for your vessel and engine.

Anyone know the gear ratio on the 1975 36 tri cabin?

I'm trying to look at purchasing new wheels for her but i don't have any information on the gear ratio. Would this be on the velvet drive (trans) or the V drive? I've heard 1:1, 1:1.5 and 1:1.9.

I can tell you that i have 21x20 non-cupped props on her now, the prop repair company is working on them now. I have asked them to knock them down in pitch as much as possible since i'm at about 3500-3600 WOT right now and it should be ~4000. I doubt they will be able to get much more out of them.

I was just curious the gear ratio and i can use the handy prop calculator on michigan wheels website. Thanks much.

if a velvet drive the following links should give you all the info you need to locate the id tag.

http://www.marinemechanic.com/site/page109.html
http://www.correctcraftfan.com/download ... Manual.pdf