A boat a motor and a trailer

70 horse Merc

Got the 70 horse Mercury on the boat and got it all hooked up and running. Have to get some 14 foot shift and throttle cables.The cables on it are only 12 ft. so I've got them running through the middle of the boat so I can try out the motor on the Mississippi this week end. The Suzuki 30 weighed 130# the Merc weighs 190# I also removed the Minn Kota power up it weighed 15# and installed the hydraulic trim that weighed 30# that came with the motor. I removed the rear starting battery and ran the cables to the front trolling motor batteries which removed another 36#. The boat is now only 40# heavier with 40 more horsepower an increase in power of 133%. Should be able to haul 4 people and a big cooler of beer and get her up on plane now.

Dave T

 

Got the boat on the Mississippi with the 70 horse Merc It ran good but needs a little TLC. It loads up a mid throttle a little, probably try cleaning the carbs and couldn't get full throttle. When I adjusted the throttle linkage to get full throttle it wouldn't idle all the way down. I'll check it out better when I get the new throttle and shift cables. I ordered two 14 ft. cables and a complete rotary steering system from Discount Marine. My homemade steering system was designed for the original 11 horse Briggs conversion and wasn't allowing me to turn as tight with the Merc. I'm hoping they'll be here today as I've got the thing all tore apart now and part of the new linkage made. I'm hoping the weather will stay warm and I can get her back on the river the weekend after this. Did manage to get her up to 29 mph with me and my wife aboard. I'm pretty sure she can do better once I get all the bugs out and play with the trim some. I also want to get a tach so I can see what kind of RPM she's turning.

Dave T

 

Got the new rotary steering and the new shift and throttle cables installed. Had to put a new water pump in the 70 horse Merc. Had her on the Mississippi all weekend she ran pretty good. The tach should be here today. Not sure if I'll be able to get her back on the river again this year the weather's supposed to turn pretty cold by next weekend and I better start getting ready for Winter I guess.

Dave T

 

Wear a good coat and report back to us . . .

 

Winter comes quickly to Iowa. Have fun.

 

Got the tach installed and wired, haven't had it running yet to see if it works but I'm pretty sure it will. I don't have the muffs to try it right now, I'd borrowed them from a friend and he needed them back so I'll buy a set of my own. Sounds like pretty soon we're not going to be able to bye gas without alcohol. Is there anything we can do to these older motors so they can run on alcohol gas?

 

Hardened valve seats or lead substitute additive in the fuel. If it's a two stroke, then less an issue.

 

Yes it's a 2 stroke a 1978 70 horse Merc I've heard you can't run these on alcohol gas because it will destroy the fuel pump diaphragms, fuel lines and other rubber parts. My Mercury service manual warns against using gas with alcohol in any motor prior to 1989 and says to stay away from it if possible on all outboards. I've heard the government is going to require that all gasoline has to contain at least 10% alcohol and most of the stations in Iowa are already switching to only gasahol. I don't know if alcohol resistant parts are available for older outboards or not. I'll call our local Mercury dealer tomorrow and see what they have to say. If anybody has a solution let me know.

Dave T

 

Yes, ethanol does eat up the older gaskets, O rings, needle tips, fuel lines, etc. Most can be retro fitted with the newer class of materials that aren't prone to this problem. All of my small motors have had to have their lines replaced and carbs rebuilt for this reason. You can buy ethanol free fuel, but it's not cheap. Places where you can buy race fuel will usually have it, as well as places that service, rent or sell landscaping equipment. I went this route for a while, until I got everything rebuilt. One way around it is to make sure you run the engine dry at shut down, so fuel isn't in the bowl or the lines.

 

Had the boat on the Mississippi for the last time for this year. I wore a coat as Par suggested but it was still cold. I rented a slip for the weekend and did some playing around using the bow mounted trolling motor. It's real tight getting into the slips around other boats and I'm definitely not the greatest boat driver. Using the trolling motor makes it much easier and saves wear and tare on the outboards gear box. The only problem with the bow mounted trolling motor was that it didn't have reverse so you have to turn it 180 to reverse it. Had the boat up to 33 MPH at 4800 RPM it's supposed to turn 5500 so it must be over propped a little bit. The prop that's on it is 10and 5/8" diameter 15" pitch. Don't know if I'll change it or not as the boat is plenty fast enough and most of the time I only run it about half throttle anyway. After we got back home I got to thinking about making the trolling motor so it was reversible so I got four 70 amp 12 volt relays and wired them so I can reverse the motor with a dash mounted switch this should work and make it much easier getting in and out of the slips.

Dave T

 

Made a reverse lock device for the boat motor. I'd removed the shock absorbers to make it easy to lift up the motor to connect the brace that goes to the trailer for towing. The motor would raise up in reverse if you opened the throttle too quick it wasn't a big problem but I figured I was running out of things to do to the boat and it's going to be about six months before I can get her back on the Mississippi again. I'm hoping for an early Spring without so much rain next year. It was the 22nd of July this year when the river finally got down enough to get her in the water.

Dave T

 

Getting ready for Summer

Fired up the 70 horse merc for the first time this year, not much to do to the boat just give it a good cleaning and I think she's ready for water. Moved the boat into the shop and then went to the campground to check things out. We've had lots of snow and record cold all Winter. I'm ready for some warm weather it's supposed to get up to 50 degrees today and above freezing all week should get rid of a lot of snow just hope we don't get too much flooding this year. Here's a few pics.

 

Hi Dave,

Man those pictures make me glad I live in Florida. Hope it warms up soon for your guys, of course is a slow way so it doesn't create too much water.

John

 

Back on the Mississippi

Just wanted to say Hi to everybody. The Mississippi finally got down enough to use the boat ramp. I rented a slip for the weekend and had the boat on the river as much as possible. She ran really good with no problems the river was really rough with all the boats and the wind. She handles rough water really well and rides decent as long as you keep the speed down. Here are a few pics.

Dave T

 

Last time on the Mississippi this year

Took our last trip on the river for this year. It was a short summer we didn't get on the river till the end of July because of the flooding. I'm planning on stripping as much weight as possible off the boat this Winter and turning her over and adding another 1/2" layer of plywood to the bottom. Earlier this Summer we were doing some exploring on the back waters of the Mississippi and got into a restricted area that must have been logged when the river was real low sometime. The tree stumps were about 2" under the water and I managed to hit about 4 or 5 of them before we found our way out. The only damage was a small crack in one of the water tight compartments in the bows and a lot of the paint on the bottom of the hulls. I vacuumed out the water and patched it with some more glass and epoxy. The bottom of the boat is only 1/4" plywood right now and since Ive got more power than I need a little more weight shouldn't hurt anything. Here are a few pics we took while on the river.