what shaft length im confused

[noppy]

hi,
im really new to boating, i bought a speedboat last summer and refurbed it and cleaned it up nicely, didnt come with an engine, iv read up about shaft lengths, ie short standard and long, but my transom measures 21inches inbetween standard and long which do i go for? i have a potential long shaft thats i found thats upforsale.
any advise welcomed

thanks Noppy

 

[Barnacle_Bill]

Re: what shaft length im confused

See if this helps explain it. http://www.onlineoutboards.com/article_outboard_shaft_length.html

 

[JB]

Re: what shaft length im confused

Hi, noppy.

Welcome aboard.

There is no "standard" shaft length.

15"=short
20"=long
25"=extra long
30"=extra extra long.

If your transom measures 21" from top to bottom of the transom you need a long (20") shaft, because the shaft sits vertically and the transom is tilted.

 

[tashasdaddy]

Re: what shaft length im confused

agree

 

[noppy]

Re: what shaft length im confused

thanks, oh thats strange on one website i went on it said short was 15 inch standard was 18 inch and long was 23inch, perhaps its different with outboards in england, now the question is.....

will 20hp be enough for a 14ft 'speedboat' i aint really worried about being the fastest boat in the dock this year anyway , just wondered would it pane with 20hp ?


thanks Noppy

 

[Vic.S]

Re: what shaft length im confused

Surely 15" is "standard" in Johnson/Evinrude specs although some manufacturers do call 15" short shaft.

(A truly short shaft would be shorter than that although the only engine I know that is shorter is the British Seagull Forty Featherweight, aka Forty Minus, which is about 13".)

If the transom top is 21" above the water level then a 20" shaft length (Called "long shaft" by all manufacturers I think) should just about do. The crucial factor is that the water pump must be immersed!

 

[MikDee]

Re: what shaft length im confused

thanks, oh thats strange on one website i went on it said short was 15 inch standard was 18 inch and long was 23inch, perhaps its different with outboards in england, now the question is.....

will 20hp be enough for a 14ft 'speedboat' i aint really worried about being the fastest boat in the dock this year anyway , just wondered would it pane with 20hp ?


thanks Noppy

You need a long shaft, No problem planing either noppy, just as long as there's not too much weight all in the back of the boat, it should do about 20-25mph too

 

[tmcalavy]

Re: what shaft length im confused

Measure your transom straight down to the keel, don't measure along it to the keel. Put a straight edge up against the bottom of the boat, with one end out past the transom a ways. Then measure down from the top of the transom to the straight edge. Definitely sounds like you need a 20-inch outboard. The video in this thread will show you what a 20-25 hp will do on a boat.
http://forums.iboats.com/showthread.php?t=249449

 

[noppy]

Re: what shaft length im confused

hi, cheers for the replies.

i couldnt get the link to work to see the potential of a 20-25 hp outboard,

next question im picking the outboard up next weekend costing ?60 or roughly $120 and for that im getting ... 20hp outboard with tiller control (not been started for a long time) fuel tank, fuel line, and manual. as it hasnt been started for a while anything i should do before i start or attempt to start it?

thanks Noppy

oh and il get a picture of my boat as iv never seen one before and iv looked through a million pics of boats to try and find out

 

[Basher]

Re: what shaft length im confused

Noppy

I am in the process of rebuilding a 1956 Johnson FD-10 15 hp. I would recommend that you check your compression on both cylinders, you want your numbers to be close to each other and no less then 80 psi. If that is good then remove the spark plugs and squirt a little oil into the cylinders and turn the engine over a couple of times to lubricate the cylinder and rings. After that connect to the fuel tank making sure you are running a good rich mixture (20:1) as you want to make sure everything gets a good lubrication. Then open your choke and pull like a mad man! lol If it starts you are in business if not check for spark and fuel getting to the cylinders. Once the engine starts make sure you have water coming out of the exhaust if not shut it down IMMEDIATELY or you will burn out your engine.


Basher

 

[noppy]

Re: what shaft length im confused

thanks thats great info, i know for a fact it turns over already, but thats about it. oh i should probably mension im 17 and doing it all myself but i think it should be no problem doing what you've said i know my way around most engines, and i have looked in depth at my evinrude 4hp so know about most bits,
i got laughed at when i test ran my boat. in order of embarrasments
1) put the boat in the water it floated fine pushed off assuming the engine would start WRONG, luckily took so paddles so paddled back.
2) a sailing guy felt sorry came over and was like ummm is this your main engine hahahah i was like we just testing if the boat works honestly, he couldnt start it he was useless so 2 mins after he went we started it
3) and we were off hahahahah like a snail at full throttle with 4 ppl we got upto about 3 mph ppl were walking faster and laughing
4) ppl actually took photos they thought it was so funny
5) also my 4hp evinrude is a short shaft i believe so it would only work to the side of the transom

and that was are trip was great fun though and my boat didnt sink, you can tell im a boating expert

Noppy