older evinrude twin

[airshot]

First thing is to thank you all for letting me join this forum. I have recently purchased an older aluminium boat with an Evinrude outboard and I have some questions. The serial number on the name plate is "259 24 - 10648" I was told it is a 35 hp but not sure of the year, I am guessing a 1959 ? Any way it runs great, starts instantly, smooth idle, low range is excellent but the problem begins at half throttle and above. It takes a long time to pick up speed and top end feels like it is only about 80-85%. It is on a 16 ft aluminium hull, not heavy, prop looks good. Checked linkage and carb is opening up. Plugs look great. if you were to punch the throttle as if pulling a skier it takes a while to get up to speed.
I have read the first 30 pages with great interest but I see there is more than 2000 to go, so posting appears to be the quicker way to get some help.
Thanks in advance for any and all help.
Airshot

 

[wbeaton]

Re: older evinrude twin

1956 Evinrude 30 hp. Check your coils. If they are original they need to be changed. Also, check your carb settings as per the procedure in the FAQ's.

 

[Vic.S]

Re: older evinrude twin

As airshot is new I'll point out that FAQ in this instance means the "Engine Frequently Asked Questions" . The first item in the "Repair and Maintenance Index".
Not the "FAQ" that appears at the top of the page that tells you how to post smileys and that sort of thing!

 

[airshot]

Re: older evinrude twin

Thanks for the info, still learning to navagate this website. I was told the coils were changed last year as well as the water pump. Starts and runs great but just quite doggy on acceleration. Motor feels like it is laboring to get going but runs very smooth once you get it up to speed. I will keep tinkering with until I locate a newer model. Thanks again...

Airshot

 

[wbeaton]

Re: older evinrude twin

That's a good motor. There is no need to replace it. Have you set the carb, yet? If that doesn't do it, you may need to rebuild it. Check the coils anyway even though they don't sound like the problem. You should also clean and set the points at the same time. I've bought lots of motors where the owner claimed it had "new" coils or that "it ran great last year", but ended up having bad coils. Attached is a photo of some bad coils on a 1972 Johnson 6 hp that the previous owner claimed "runs great, but needs a clutch dog".

 

[F_R]

Re: older evinrude twin

Airshot, maybe you are just expecting too much? Ever consider that?

 

[CATransplant]

Re: older evinrude twin

What FR said is true. There are a lot of factors involved with making this outboard work at its best on your boat. From your description, it sounds like the engine is probably running OK, but 30 hp is probably marginal for a 16' boat, even an aluminum boat.

I'd start by experimenting with the trim angle on the engine. Tilting it up and out tends to raise the bow, tilting it down and in tends to flatten the ride. You want to find the sweet spot for your boat and loading.

Also, you didn't say whether the shaft length matches your transom height. Where is the anti-ventilation plate in reference to the bottom of the transom. On those older Big Twins, it's a little deeper than on modern outboards, by design, but a long shaft outboard on a short transom will not perform well.

Also, look at weight distribution in your boat. Where's the fuel tank...battery, other heavy stuff. It's literally amazing how much that influences performance, especially on marginal setups.

Finally, what maximum horsepower is your boat rated for? That information may answer a lot of questions.

 

[airshot]

Re: older evinrude twin

Again thanks for all the suggestions, perhaps I am expecting to much. Once the motor gets wound up it is probably performing at capacity, but the wind up takes a while and it sounds like it is laboring. The previous owner did have a bill for new coils/tune up, water pump etc. so I think the work was done.
On the first outing I found the packing nuts were loose when adjusting the carb, tightened them up and the adjustments hold. I have had many boats and motors over my lifetime, amd worked part time at a outboard motor repair shop in the summer during the 60's. I am trying to remember back to those days and what I did to fix them. I do have the trim set, the boat rides very well and all the weight (not that much) is balanced well. Of all my other boats in the past this one picks up speed the slowest, even my 14 ft with a 10 hp would get out of the hole faster, this one would outrun it when it finally got up to speed.
One other thought, does anyone know the pitch and diameter recomended
for the standard issue prop ? This is my next area to explore, the current prop is in great condition but the pitch may be off. Thanks again to all who responded.
Airshot

 

[airshot]

Re: older evinrude twin

For those of you who have been making some suggestions for me, I believe I may have stumbled onto my problem. Some research has shown this 30 hp motor came with an 11 inch pitch prop as standard and mine has a
12 1/2 and a 13" pitch prop. This is probably what is holding this motor back.
I will try the prop shop and see if they can straighten one back to 11 " pitch.
This should liven up this old motor's acceleration.

Airshot

 

[CATransplant]

Re: older evinrude twin

Yeah, that could be the problem. I had a 1958 35 hp Johnson on a 14.5' trihull. It ran a 13" pitch prop just fine. I'd think the older 30hp might have trouble with that.

Props for your engine aren't that hard to find, and they're not that expensive, brand new. They're pretty common on eBay, too, although buying a used prop that may be over 50 years old is problematic.

I have seen some new props for that outboard on ebay for around $50, though. You can also ask around at local marinas and shops. There were lots and lots of those engines in their day, and props are everywhere for them.

I'm thinking it might be cheaper in the long run to just buy a new one.

In fact, check this link for one from Michigan Wheel, right here at iboats.com:

http://www.boat-props.com/propeller..._id=47&**********=512071172&*******=841480455