1965 Johnson 33hp

[Vintage Boat Guy]

I got this old Johnson outboard from a neighbor's shed a few years back and they told me it hadn't been used since 1981, it's a RXE-13 33hp Johnson 1965. I was told it was only used a few times a summer on the weekends from 1965 - 1981 and it looks like brand new. Paint is on all the bolts and I imagine its never been apart before. I recently bought a Glen L TNT and decided that this old 33hp would be perfect for the boat. I got the old girl running on the stand and it ran fine with the original fuel pump. I changed the impeller and cleaned out the carb which was already spotless and I changed the lower unit oil and installed new B6S NGK sparkplugs. The engine had great spark and ran well on the stand although we had to give her some throttle to start. I've since put it on the boat and it doesn't stay running unless it's in gear and when I adjust the high speed jet it does very little and the high speed is almost closed before it will pick up at all wide open. It seems to be running on only one cylinder, but I checked by pulling wires off while running and it is running on both cylinders. I have a 1957 35 hp as well that has compression relief valves and was wondering if the 33hp has the same valves built in the head although it has no built in compression relief system. I was also wondering if this is a symptom of a bad head gasket. I know this motor should jump on this little boat and my 1952 25hp will out run it on a heavy 16' cedar boat full of water, any ideas?

 

[Vintage Boat Guy]

Also it picks up speed just before it runs out of fuel as it leans out and it seems to be poring through fuel compared to all the other old outboards I've had.

 

[racerone]

Check the fuel pump diaphragm.

 

[Vintage Boat Guy]

The fuel pump is fine I'm fairly sure, I think it's getting too much fuel

 

[F_R]

The only way it can get too much fuel is through the fuel pump or through the carburetor. Is the carb flooding over when you squeeze the primer bulb while not running? Are you sure the pump diaphragm isn't leaking? The High Speed needle normally should be open about 5/8 turn.

Have you checked the ignition system? You wouldn't be the first guy that got fooled into thinking you have fuel problems when in reality you have an ignition problem. Especially cracked coils!!!!

 

[racerone]

Pull the flywheel and check the coils.----Just picked up a 1965 model 5 hp.-----Both coils cracked as suspected.-----That actually indicates a low hrs motor and an easy fix.----Picked up a 67 model 6 hp and a 1960 model 10 hp.--Bonus , both had new coils already.

 

[Vintage Boat Guy]

It has very strong spark, so I never checked the coils, usually I do check em and replace as needed. They are probably original, I'd have to check for sure, I usually can tune a carb fairly well, I took it apart to make sure the float wasn't sticking, and it doesn't flood when not running. I just couldn't believe how much fuel it went through and it seemed like it was only running half throttle.

 

[F_R]

Your symptoms shout out "Cracked Coils"!! It will spark when cracked, but not run right.

 

[Vintage Boat Guy]

I was gonna check the coils and I ran out of time on the weekend, I have a pair I was gonna use on another project that came out of a 3hp that I'll put in the 33hp. I'll follow up next week

 

[gm280]

VBG, If the fuel pump has even a pin hole in it, extra fuel will be sucked in via the fuel pump diaphragm. And if there is extra fuel getting in that way, the high speed needle adjustment will have very little effect. So check it before spending money on parts. It is easy to check and simple to rebuild. JMHO

 

[oldboat1]

^^^also gotta believe the pump is suspect, unless you checked it out. After all that time stored, the diaphragm has to be done for, IMO. The replacement pump is the little square one, and if you have one of those around you might try it out. The original pump is obsolete, and it may be hard to get a replacement diaphragm -- similar to other pumps, but not sure about the exact fit. (It seems to me someone found a Sierra kit here for a sister motor, but not sure of that.)

Pump and ignition rehab.... Sounds like a nice find.

 

[Vintage Boat Guy]

I have a few smaller fuel pumps lying around, family member had them for an 18hp Evinrude, I used the fuel pump in my 1968 OMC snowcruiser so I believe its a good pump

 

[oldboat1]

Yeah, I'm a big believer in swapping parts to troubleshoot -- good to swap out a pump, if you can.

 

[Vintage Boat Guy]

Nothing worst than buying a part you didn't need to replace. I've got a 1957 35hp I could steal parts off of too if need be

 

[Vintage Boat Guy]

Coils it was, should have known better. Engine runs beautifully now