bertram31.com

I am sure that some of you are using outboard motors for trolling... I have a B28 with a pretty sturdy swimming platform. I have reinforced the transom that in the B28 is very weak and also have enlarged rudders. Now I have to choose a small outboard motor to be mounted in the swimplatform. I need to trool at speed of 1.5 (max 2 knots) and I like to have a motor as light as possible just for this purpose. What motor do you suggest ?

Do you own a Bertram orBayliner? I have never heard anyone say a Bertram has a weak transom.

ScottD

I said Bertram 28...Yes the transom area is a kind of weak. You can push with your hand and it would flex. This is the case for the 28. I dont know about the 31. I reinforced inside with wood and glassed it before installing the swim plat... now is very sturdy.

I have a 15 hp Honda 4 stroke on an aluminum flatboat that is the cat's meow. Will idle as slow as paddling. Not a featherweight, tho, probably weighs in at 120#. Burns almost no gas.

UV

Thanks UV but I would like to know how a small outboard would perform on a B28 or B31 transom. I asked to a local dealer which engine (hp, 4s, 2s..) would be appropriate for trolling at 1.5 knots on this type of boats and he answered "ask Bertram"...here I am

I beefed up my transom in preparation for a kicker as well. My research indicated that the smallest outboard suitable is a 9.9 Yamaha high thrust with extra long shaft.

A smaller outboard may very well push the boat but you will have no steering control in winds or cross seas. The 9.9 also has the benefit of being a much better "get home" motor. I think you will be unhappy with anything smaller.

I would also beef up the swim grid supports before mounting.

good luck
Cliff

Lore,

1.5KT, (1.7MPH, 2.8KPH), is pretty slow, so it won't take much thrust to move your B28 at that speed...

An alternative thought would to use an electric trolling motor. Minnkota make several salt water versions that could possibly do the job. They even make an electric outboard model that would mount directly to your swim platform and has inboard controls that could be cockpit mounted.

You'd, of course, need dedicated batteries, charging system, and some creative thinking to work out the details, but it'd be worth some investigation.

The Minnkota E-Drive system can be found at http://minnkota.sramarketing.net/produc ... ?pg=edrive & other possibilities linked from there.

If you went with a normal outboard engine, you should be able to attain your trolling speed with as little as a 10 HP motor. You could probably even go smaller, but you'd have to run the engine at a much higher RPM. Outboard engines are, however, designed to run best in the upper 20% of the RPM range. Slow extended RPM ranges on outboard engines can lead to real maintenance and longivity problems.

Steering will be a problem unless the motor or engine is located exactly on the center line of the boat.

Br,

Patrick

Didn't Minn Kota or someone make electric motors that attached to the top of the trim tabs?

Rawleigh,

That's Lenco Marine, (Trolling Tabs), but unless the boat were haulled between uses, (in/out storage or davit), maintenance could be a nightmare.



Br,

Patrick

Thanks guys for the advices. CaptPatrick, I thought that the electric motors did not have enough thrust for kicking a boat like the B28. I will do some research in this direction. Even if at the moment it will be more likely that I will go for a traditional solution. Here near and along the italain cost we fish mainly a type of yellow tail (ricciola), dentex, gilthead and blufish. We use squids and gar-fishes as live baits and we troll at 1.5 knt. With artficial baits we troll of course at higher speed.

I would experiment with trolling bags and one engine in gear before attempting to mount an outboard.

Locking the shaft on the neutral engine will create drag enough to slow the boat.

Both engines in gear at idle produces what speed now?

Bruce, with 2 engines at idle about 4+ knts (GPS), 1 engine hardly below 3knts. Too fast for the live bait fishing we use to do here. Trolling bags might be an option. An advantage of having an outboard is that it can be used as an alternative to the boat engines even when you troll at higher speed.

Based on my calculations, it comes out to 4hp.

But the formula I use says no wind or tide, period.

Plus outboards don't really put out the full hp untill you reach the upper rpm limits at 5000 so you'd be winding that engine up all the time.

To be safe I'd look at a 9.9 minimum.

After mounting the bracket, try to borrow a unit to try before you buy.

I had a customer that had a 9.9 Honda on 27' outboard powered boat. His main unit failed and he fired up the little one and barely made headway against the wind and tide at full throttle.

What gears are in the boat? Are you sure that trolling valves are not available as an add on? If they are TwinDisc or ZF you may be able to add trolling valves....just checking.

Scot

Scott is right. Trolling valves would be the answer and I'll bet they'll cost less than a new engine, bracket installation, and fuel line installation. Walter

Yes, trolling valves would be the best solution but unfortunately I have FW Merc 260 wih old trasmissions that are not compatible with trolling valves. I can double check but I am pretty sure that they are not