1972 Johnson 65 Starting Problem

[JustMrWill]

This is my first OB so I am still learning. I have an OEM service manual for it. Been trying to get this motor running...it was free and I only started it up briefly when I first got it a year and a half ago (before my restore project).

If I spray Seafoam Deep Creep into the carbs...and crank it...it will fire up for a few seconds then die. Reving the throttle does nothing to keep it running. After it dies...it won't start without spraying more seafoam.

I have removed the air silencer cover and now have access to the carbs.

Is the carb bowls suppose to fill when I squeeze the primer bulb? I have removed the drain plugs from the carb bowls after priming and nothing came out. Does that mean that there is a blockage in the fuel line?

I haven't tested the fuel pump yet...I am under the assumption that the priming bulb will get enough fuel to the carbs to start it...so I am focusing on that issue first. Once I can get it started and running for more than 5 seconds...then I will tackle any other issues that may arise.

Any suggestions would be appreciated.

Thanks.

-JMW

 

[Barnacle_Bill]

Re: 1972 Johnson 65 Starting Problem

Sounds like time for rebuilding the carbs. The needle is probably stuck to the seat not letting gas in. And if it were me I'd do the fuel pump at the same time.

 

[JustMrWill]

Re: 1972 Johnson 65 Starting Problem

Sounds like time for rebuilding the carbs. The needle is probably stuck to the seat not letting gas in. And if it were me I'd do the fuel pump at the same time.

So..are you saying that there is only one needle for the 3 carbs? or that all 3 are stuck? I can see that from the pump..the fuel line goes to the base of the middle carb..then back out and splits 3-ways. Is there a check valve or something there that could be stuck?

I am planning on rebuilding them over the winter...I was just hoping to splash the boat once before so I can see how it sits/rides in the water..and work on seating/weight distribution over the winter.

Btw...anybody know what carb kit I need?

-JMW

 

[Benny1963]

Re: 1972 Johnson 65 Starting Problem

had same prob on 1972 50 johnson
fuel pump was weak needles in 1 carb was stuck .low speed jets clogged
and float in one carb set wrong. bad gasline and tank vent stopped up
your best bet is to build pump build carbs ,check for air or gas leaks
check tank and bulb. thats what it took on mine .
but after running it had to change thermo and waterpump
good luck.b1963

 

[HighTrim]

Re: 1972 Johnson 65 Starting Problem

You should never spray deepcreep or starting fluid into your carbs to start, always use premixed fuel. If your fuel lines are hard and brittle, or have any type of air leak in them, replace them, you can gt the fuel line at any boating goods store, just make sure you know the inner diameter sizes that you will need, some sizes change from location to location, and Im not 100 percent sure about yours.

Here is the carb rebuild kit you will need right here on iboats, with float.
http://www.iboats.com/mall/partfind...gd_poid=109344&gd_row=58&**********=764424828

 

[JustMrWill]

Re: 1972 Johnson 65 Starting Problem

Thanks...

I will be rebuilding them once I get the funds/time (prob over the winter).



One more question:
How much fuel should the fuel pump...pump? How should I test?
I have looked on iboats but they don't have the year/hp replacement pump...does anybody know if anything they have works?

Thanks.

-JMW

 

[JustMrWill]

Re: 1972 Johnson 65 Starting Problem

Anybody on fuel pump performance question?

The manual says that the fuel pump can not be repaired and should be replaced as a whole unit...but I found this

http://www.iboats.com/mall/partfind..._row=72&keywords=18-7820&**********=166522847

fuel pump repair kit...now I am a little confused. Is this the correct repair kit? I understand that if the diaphram is compromised...I am screwed..but should I replace the gaskets?

After spraying some more carb cleaner into them...I was able to fire up and keep it running at a high rpm. I am very happy that it "runs" I still want to put it on the water and make sure it shifts under load etc.
before the winter. I am ordering the carb kits today so I can rebuild them over the winter.

-JMW

 

[just plain ole Bill]

Re: 1972 Johnson 65 Starting Problem

Just went through the same thing with my '72 65hp. The fuel pump can be rebuilt and rebuild kits come with new diaphrams and gaskets. If the little flapper valves are corroded then your in trouble unless you can find replacements. I got lucky and bought a used fuel pump off ebay. They are not all that hard to find. You need a 438559 fuel pump. I bought a used one for $5. New they are around $80. They are available at a few marine shops via the internet. Just do a search for the above part number.

Might want to go the the FAQs on this site about firing up an older motor. Using them as guides I got my old motor fired up and running well enough to check it out then went back and worked thru the FAQs in more detail once I was convinced the motor was worth the time and money.

If you look at the side of the carbs just below and left of the fuel pump you'll see a tiny short line that goes to the middle carb. It will be hidding behind a larger line that is the main carb supply line. It is very easy to bend this little line enough to stop the fuel flow. Look between the starter and the carbs to see this little fellow. There are three different size lines on your fuel delivery system from the fuel pump to the carbs

Good luck!!

 

[JustMrWill]

Re: 1972 Johnson 65 Starting Problem

UPDATE: (I hate leaving threads open)

I rebuilt the carbs and fuel pump a couple weeks ago. The bottom carb was full of crude...the other two now so bad.

Boat fired up after a couple turns of the key. I took her out to the local lake (with no seats/interior/windshield) and she FLEW at 1/2 throttle. I think I can call this issue SOLVED.

Thanks for the advice/info.

-JMW