1948 2.5 hp Johnson HD-25 won't fire

[McCruiser]

Anyone know what the initial jet settings should be ?

It has spark and appears to be getting fuel and has good compression (about 60 psi compression in each cylinder) but she won't even fire.

Any suggestions?

thanks.

 

[lindy46]

Re: 1948 2.5 hp Johnson HD-25 won't fire

Try 1.5-2 on the low speed and 1/2-1 on the high speed. Have you tried spraying some premixed fuel directly into carb? 60psi may be a little low. Try spraying some seafoam in the cylinders and let soak overnight.

 

[JB]

Re: 1948 2.5 hp Johnson HD-25 won't fire

http://forums.iboats.com/showthread.php?t=299680

 

[2.5putput]

Re: 1948 2.5 hp Johnson HD-25 won't fire

I have had the same motor for 20 years and have never used it. I just worked on it tonight and it has 60 psi compression in both cylinders. It will run on starter fluid for 5 seconds but stops after that. It leaks around the primer pump when you prime it. Anyone know if parts are available, like carb kit or water pump?

 

[ebentraywick]

Re: 1948 2.5 hp Johnson HD-25 won't fire

a engine needs at least 80 psi 2 run a average motor has 115 psi get some gast sealer it works great

 

[samo_ott]

Re: 1948 2.5 hp Johnson HD-25 won't fire

Funny, I also have had an HD-25 for ~3 years now and today for the first time I also tried to start it. But it did not start. Close though... Will keep trying... Boy it sure is a light engine! I was also trying different settings...

I have the parts manual for the HD-25 if anyone wants it, PM me with your email address.

 

[F_R]

Re: 1948 2.5 hp Johnson HD-25 won't fire

Funny, I also have had an HD-25 for ~3 years now and today for the first time I also tried to start it. But it did not start. Close though... Will keep trying... Boy it sure is a light engine! I was also trying different settings...

I have the parts manual for the HD-25 if anyone wants it, PM me with your email address.

The slow speed needle on the HD is extremely sensitive. 5/8 turn open to begin with, and very tiny tweaks from there. High speed, 3/4 turn or so.

 

[jbjennings]

Re: 1948 2.5 hp Johnson HD-25 won't fire

My son could crank our HD-25 when he was 6 years old. I don't think you'll have any problem getting it to run with 60 psi. It may not idle as nice as it would have new, but it WILL crank and run. I wouldn't say that about too many motors but on that little 2.5hp, I think it will run o.k. Those motors will let you know it if they're running hot-----they won't idle unless they're staying cool enough. Mine runs hot and I'm yet to solve the problem. If I get a chance, I'll post my compression results. Mine runs really nice until it overheats, and cranks extremely easy.
Good luck,
JBJ

 

[JB]

Re: 1948 2.5 hp Johnson HD-25 won't fire

a engine needs at least 80 psi 2 run a average motor has 115 psi get some gast sealer it works great

Wrong, wrong and wrong.

50-60psi is typical of a small rope start outboard. You will never get 115psi from a HD-25 unless you turn it with a strong electric motor.

Don't know what gast sealer is, but it is probably bad news for small 2 strokes.

Please restrain yourself to giving advice on something you have some knowledge of.

 

[samo_ott]

Re: 1948 2.5 hp Johnson HD-25 won't fire

The slow speed needle on the HD is extremely sensitive. 5/8 turn open to begin with, and very tiny tweaks from there. High speed, 3/4 turn or so.

Hey. Good info FR. Thanks. I set it up to 5/8's and 3/4ers and it fired right up today! Didn't stay running but that's another issue. And the carb leaked... another issue...

 

[samo_ott]

Re: 1948 2.5 hp Johnson HD-25 won't fire

Welcome to the forum. Send me a private message (PM) with your email and request please for the parts manual.

 

[catulin24]

Re: 1948 2.5 hp Johnson HD-25 won't fire

Hi there, I recently buy an HD25 and I would like to have the Parts manual. My email is Thanks

 

[catulin24]

Re: 1948 2.5 hp Johnson HD-25 won't fire

Hi there, I am trying to fix an HD 25 Johnson. Could be helpful if I get the repair manual. My email arcilac@yahoo.com Thanks

 

[nwcove]

Re: 1948 2.5 hp Johnson HD-25 won't fire

I have had the same motor for 20 years and have never used it. I just worked on it tonight and it has 60 psi compression in both cylinders. It will run on starter fluid for 5 seconds but stops after that. It leaks around the primer pump when you prime it. Anyone know if parts are available, like carb kit or water pump?

dont try to start your 2 stroke engine with starter fluid! a few tries at that and your 60psi comp could or will change for the worse!

 

[EarleW]

Re: 1948 2.5 hp Johnson HD-25 won't fire

EDIT: Earle, please read and respect our rules. You broke three of them today.

Thanks for your future cooperation.