Hd-25... Help!!

Niedhogg

Seaman Apprentice
Joined
Jun 29, 2010
Messages
41
2011-07-05_19-23-36_496.jpg
I need whatever is missing from this picture! Do you see the hole? Where can I find this part??
 

JB

Honorary Moderator Emeritus
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Mar 25, 2001
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45,907
Re: Hd-25... Help!!

How about filling the big hole in the post, where you tell us a bit more about your problem?
 

Niedhogg

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Jun 29, 2010
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Re: Hd-25... Help!!

How about filling the big hole in the post, where you tell us a bit more about your problem?
I'm sorry, I thought it was more obvious...
I picked up this Johnson Sea Horse HD-25, 2-1/2hp motor the other day, and have been fooling with it a bit trying to get it started. Cleaned the tank, added fresh gas and pushed the primer and pulled the rope and she tried to fire! I pulled and adjusted things many times and never got more than a few pops. Well I gave up, moved it to the shed and then started back into it a couple days ago, cleaning the plugs, double checking all the adjustments and all, well I pumped the primer acouple times and fuel starts shooting out the hole in the picture, where the fuel enters the engine and the low speed mixture screw meet up in the middle there. I thought maybe it was just a screw that fell out in the move the other day, but looking back through all my pictures I now see that it has been missing since the purchase, and it may be more than just a screw, maybe a hollow type scew that holds that block into place while allowing fuel to pass. I need one of whatever this bolt is called in order to get it running...
Anyone know where I can get one, and what it's called?

Thanks, Dave
 

JB

Honorary Moderator Emeritus
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Messages
45,907
Re: Hd-25... Help!!

I bet the guys at www.aomci.org would recognize that, Dave, or you might even try our salvage yard list (in the Top Secret File ^^^).

Good luck. :)
 

Niedhogg

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Re: Hd-25... Help!!

JB, I may have discovered after some research, that I am missing nothing.. From what I understand, the low speed mixture block(in my picture) is basically a separate carburator of sorts, and that hole is an air inlet for the slow speed idle cicuit. In fact, the instructions say that if the slow speed seems to be malfunctioning, to open the needle valve 4-5 turns and depress the primer several times to clear it of debri. I am relieved! I haven't messed with it since I thought it was missing something, but you know, after I noticed the fuel squirting out I had given it a pull for the heck of it and it tried to start! But then I put it away thinking I had to hunt down a part. Guess I will try again tomorrow, with renewed vigor!
 

Steve A W

Petty Officer 1st Class
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Jun 23, 2009
Messages
267
Re: Hd-25... Help!!

Niedhogg
If You need more help with Your motor, Go to The A.O.M.C.I. web site mentioned above. Go to the " Ask A Member" forum.
There is a fella there named Lloyd, He's an expert on the old 2.5, 3 &5hp Johnsons from the 40ies & 50ies.
He will want to know the compression readings on the motor.
If anybody can help, He can.
Good Luck
Steve A W
 

wbeaton

Commander
Joined
Jul 30, 2006
Messages
2,332
Re: Hd-25... Help!!

Yup. Nothing wrong there. That is the low speed mixing valve. Aren't old outboard cools?
 

jbjennings

Captain
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Jul 18, 2007
Messages
3,903
Re: Hd-25... Help!!

Just to pass on good advice given to me.........

Make absolutely certain that your HD-25 is cooling properly. If not, it will NOT idle once it begins to overheat. I've put a new water pump eccentric on mine and it still doesn't seem to cool enough to idle after even a short run. I believe the fuel gets too hot in the carb and fuel lines and boils. The little leather gaskets in the carbs are a pain as well. The aomci.org website is a good idea to look at . The "askamember" forum is a must on these. If I remember correctly, if you don't have enough compression on them, they won't run right, either.
Mine has developed a leak in the cast aluminum tank. I've got a replacement, bu haven't gotten around to cleaning it out and solving the other problems. At one time, mine cranked so easily my 4 year old could crank it cold, so if you get it right, they're nice running little motors. The points need to be absolutely SPOTLESS on these!!!
good luck with yours,
JBJ
 

Niedhogg

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Joined
Jun 29, 2010
Messages
41
Re: Hd-25... Help!!

Yup. Nothing wrong there. That is the low speed mixing valve. Aren't old outboard cools?

They are very cool! I got it running tonight too! I ran it for a few minutes anyway, need to mix up a new batch of gas, I have found out that it's too lean and needs to be 16-1. How do I know if the water pump is working on this old girl? It must discharge with the exhaust tube, so I can't tell..

I also have a 3 hp of the same era and brand that I got with it, but it needs a few parts like a rope and pull handle, a few cover screws for the re-coil and the lower cowl, and an original tiller handle, it has a homemade handle, for I assume a canoe, that's about 3' long, lol. I'm picking up a couple Mercury Rockets tomorrow, model KE4 7.5hp. I'M HOOKED ON OLD OUTBOARDS!!! LOL, I had a Monkey Wards Sea King 5hp last year that I picked up at an auction for next to nothing, that was in excellent shape, ran great and everything, but I sold it too my neighbor after much persistance.
 

Niedhogg

Seaman Apprentice
Joined
Jun 29, 2010
Messages
41
Re: Hd-25... Help!!

Just to pass on good advice given to me.........

Make absolutely certain that your HD-25 is cooling properly. If not, it will NOT idle once it begins to overheat. I've put a new water pump eccentric on mine and it still doesn't seem to cool enough to idle after even a short run. I believe the fuel gets too hot in the carb and fuel lines and boils. The little leather gaskets in the carbs are a pain as well. The aomci.org website is a good idea to look at . The "askamember" forum is a must on these. If I remember correctly, if you don't have enough compression on them, they won't run right, either.
Mine has developed a leak in the cast aluminum tank. I've got a replacement, bu haven't gotten around to cleaning it out and solving the other problems. At one time, mine cranked so easily my 4 year old could crank it cold, so if you get it right, they're nice running little motors. The points need to be absolutely SPOTLESS on these!!!
good luck with yours,
JBJ

Boy were you right about the gas boiling... I gues it needs a pump! But it runs... you get all excited when you have a new toy and want everything to be perfect, but then you have to face facts and realize that this damn thing is near 65 yrs old! LOL! They are very cool old motors, and I'm very excited about the pair of Mercs I'm getting tomorrow! And this will start all over again... hehe!
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: Hd-25... Help!!

That needle on the front of the powerhead is supposed to be set at 5/8 of a turn out, from lightly seated and the high speed sets at 1 turn out. Cool little motors. I'm rebuilding one of those myself, but older.
 

jimbo_jwc

Ship Happens
Joined
Dec 19, 2010
Messages
633
Re: Hd-25... Help!!

Low speed idle fuel / air? puts gas in through crankshaft . Have a pair of these and i alwas use on shallow river runs . The water vent pee hole is drilled into a 90 fitting at bottom cowl level . always ran them out of fuel when done as the floats need work/revarnished .
 

Niedhogg

Seaman Apprentice
Joined
Jun 29, 2010
Messages
41
Re: Hd-25... Help!!

Low speed idle fuel / air? puts gas in through crankshaft . Have a pair of these and i alwas use on shallow river runs . The water vent pee hole is drilled into a 90 fitting at bottom cowl level . always ran them out of fuel when done as the floats need work/revarnished .

Thanks I'll have to check that out, I did not notice any water peeing out of anywhere while it was running. Probably needs an impeller... Have you ever had a problem keeping them cool? Someone esle mentioned they are difficult to keep cool. I've also read that they vapor lock easily as well, and described a fix for that problem.
 

jimbo_jwc

Ship Happens
Joined
Dec 19, 2010
Messages
633
Re: Hd-25... Help!!

Its a small hole drilled into 90 degree water fitting . Ive had to clean it out with small wire and blow out from river gunk in
 
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