1970 chrysler 55 outboard not circulating water and leaking drive oil.

m_sherman211

Petty Officer 3rd Class
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Dec 31, 2010
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I have a 1970 Chrysler 55 hp outboard and have been having issues with engine.
I bought this boat a couple of years ago and right off the bat I had to have the impeller changed.
I used it twice after it was changed. The next year I went to use it and it would not circulate water again.
Any ideas on what it could be?
Also when I pulled it out of the water gear oil is leaking out of port holes from bottom of unit.
Somebody told me the shaft has groves worn on it and if I was going to keep it I would have to change gear oil a couple times a year.
I'm really contemplating buying a 90's motor.
 

Frank Acampora

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Jan 19, 2007
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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

Glad you decided to post over here. Your problems actually sound relatively minor but blown out of proportion by someone.

First to the easier problem: Are you certain it is gear oil leaking out the lower unit? All exhaust passes through the lower unit and unburned engine oil will collect there. It will drain from the weep holes in the lower unit. Smell it. If it smells like gasoline, it is unburned oil and this is normal. If it has a skunky and sulphur odor, it is lower unit lube and then yes, you will need to change a seal. If you have never smelled it go to a full service gas station and ask to smell rear end oil. It is very distinctive and once you have smelled it you will never forget.

Some one told you the shaft has grooves worn in it. Did they look at it? If not, they were simply blowing smoke up your butt. Don't listen to these types.

Even if the drive shaft does have deep grooves worn into it from the seal lips, it is so easy to change, it will surprise you: Drop the lower unit, remove the water pump, and simply pull the shaft out. Push the newer one in and--Bob's your uncle.

However, don't worry: A little grooving on the shaft will not cause a leak. It needs real bad damage to leak.

Now, as far as pumping water: The impeller should last a couple of years but if you run it dry--that is run the engine out of the water-- you can destroy an impeller in as little as 30 seconds and sometimes the rubber can age and take a set just sitting. So, Check the impeller again and also check the thermostat on the back of the head.

Everyone is different in their tolerance for aggravation and frustration and you may find that you simply do not want to mess with the engine. Ultimately it is your choice as to swap or not. However, with the knowledge gained here you can easily repair the engine you have. Don't forget, if you swap engines, you may still have problems after doing all the work to switch them.
 

wickware

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

Do you have any pictures of your stated issues? I will try to post pic of my 1970 35hp Chrysler that could be the same as you 55 hp except for cyl bore and piston giving you 55hp over my 35 hp.

1. What was the conditions of the impeller housing? I purchased used in 1984 and changed my impeller in 09 and it was still pumping good w/o excessive wear or cracks. I avg 6 gallons or 2-3 hrs of running 5-8 short fishing trips per summer.

2. Are you doing any idling w/o being in the water? I have always fires instantly w/o water vs any idling or running vs finding problems 120 mi from home. I always start in a 55 gal barrel at the start of every summer or just before.

3. If oil is coming from a port hole it?s possibly unburned gas/oil mix vs gear oil.

4. Gear oil is usually lost at un sealed plugs (bad gasket or not tight) or bad prop seals. Is your gear oil murky from water mixed with the oil or does the prop shaft area leak oil?

Good Lucy on Maintenances or Changes. There Will Always Be Work If You Are Having Fun!!!

PS. Frank, You are Detailed, Good and Quick!
 

Attachments

  • Boat's Lower Unit old Seal's  8 hrs Leak test.JPG
    Boat's Lower Unit old Seal's 8 hrs Leak test.JPG
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  • Boat's Lower Unit's Prop Shaft Seal & Cage O-Ring Replaced.JPG
    Boat's Lower Unit's Prop Shaft Seal & Cage O-Ring Replaced.JPG
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  • Boat's Lower Unit new Seal's after  24hrs Leak test.JPG
    Boat's Lower Unit new Seal's after 24hrs Leak test.JPG
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    70 Chrysler 35 HP Water Pump Checked Last In 1985 10.JPG
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    1970, 35 hp Chrysler impeller-.JPG
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oldboat1

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

For what it's worth, I had a '72 55 for a number of years, and had no real problems. I say no real problems, in that I was new to outboards and didn't recognize that the starter needed rebuilding -- lived with that much longer than I should have. As you have already heard, that black oil may very well be unburned fuel or some carbon sludge leaking out from the leg. And seals aren't really that hard to replace (coming from a non-mechanic), if it comes to that. On the cooling issue, I would think first of a thermostat (if it has one). You can remove and test a t.stat, but it blocks water circulation, of course, if it gets stuck closed.

guess I would want to be sure first that it really isn't circulating water. nothing coming out of the port on the leg? The fix is usually to pull the lower unit and try to locate the problem -- possible, if unlikely, for example that the impeller key has sheared off. One test you might make is to run it on a flusher. This essentially bypasses the waterpump, and pretty much tells you the problem is pump-related if you get cooling on the flusher. Again, there is the t.stat issue if that model has one.
 

wickware

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

Hello oldboat1, I questioned the thermostat issue preventing ?any circulation? due to getting instant cooling when I start cold. With this flow it takes me a while to warm the Eng in cool weater.

I also wonder if the like of cooling water is while in a lake or Etc or 55 gal drum vs muffs?
 

oldboat1

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

backatcha, wickware. Like you, I run them in a barrel -- keep a hose running in to keep it cooler, clean out some exhaust debris (not cool for the environment, but neither are my two-cycle motors...), and replace any water lost. That's probably pretty close to running in the lake, where water temp. can be a factor in a motor without a t.stat or a t.stat that is stuck open. Muffs can be useful, but without drawing water and backpressure, can't really tune an engine. Come back and correct me if I missed your point.
 

wickware

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

Oldboat1, I feel we are experienced the same issues of only idling issuers in a barrel. I learned that I needed to be in the lake/river full body of water for resistance for a good carb/ign test tune (even w/o leaving the trailer. Open water is better for WOT and Planning issues. Yep Planning at 32 MPH LOL!
 

m_sherman211

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Messages
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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

I don't think you can put muffs on this outboard. Cause the pick up is directly above the prop.
backatcha, wickware. Like you, I run them in a barrel -- keep a hose running in to keep it cooler, clean out some exhaust debris (not cool for the environment, but neither are my two-cycle motors...), and replace any water lost. That's probably pretty close to running in the lake, where water temp. can be a factor in a motor without a t.stat or a t.stat that is stuck open. Muffs can be useful, but without drawing water and backpressure, can't really tune an engine. Come back and correct me if I missed your point.
 

m_sherman211

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

Thanks for all the input. I will have to look into this a little closer.
 

eurolarva

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4,182
Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

Take the lower unit off and look at the impeller. It is probably toast. I have had to replace impellers a couple times a year till I could get one to work. Like everything else marine parts are being made cheaper and cheaper. Also make sure you use a 6 vane impeller instead of a 10. The number is F433065-2. The 6 vane seems to push more water and I have had less problems with them breaking. When you are pushing the impeller into the pump while it is on the shaft you need to make sure you turn it clock wise (either the pump or the drive shaft) to make sure the vanes bend in the correct direction. Also make sure the impeller is in the drive shaft.

The oil is draining gas, oil and exhaust going into the water. Chrysler was not very worried about the environment back in the 70s and drained all unburned fuel that condensed in the motor via a hose going from the clylinders to the kingpin and draining out the leg.
 

oldboat1

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

all good points (incl. limits on running in a barrel). When replacing an impeller on my 10hp, I was seeing some impellers (ebay, probably) with 10 vanes, or maybe more -- hadn't seen that before, or hadn't noticed. As RearAdmiral says, more might not be better if you have a choice. As I think R.A. is also saying, you want to be sure that the shaft key is in place so the impeller will spin with the drive shaft.

not sure about the flusher fit -- can cut a rubber flusher down to fit, unless there is no intake on the sides of the housing.
 
Last edited:

Frank Acampora

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Jan 19, 2007
Messages
12,004
Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

I think he has the early lower unit with a perforated plate above the prop. It is held into a groove in the casting by one bolt. It uses prop wash to help force water into the pump--not really very effective and there are limited ways to attach a custom flusher. Regular muffs have no opening to cover.

The ten vane impeller is early-- at least 1967 or earlier. It was used on the 55 on up to the two piece lower unit three and four cylinder engines. The ten vane impeller actually pumps less water because there is less room between the vanes and the vanes are a bit thicker. The impeller of choice is the six vane unit. I don't know exactly when the ten vane was supplanted with the six vane, certainly before the one piece lower unit was designed in 1979. I am surprised that they still can be found.
 

oldboat1

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Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

good info. I probably saw a NOS impeller (10 vane) on Ebay when I was shopping around, or maybe in one of the old NAPA marine catalogs I sometimes refer back to.
 

m_sherman211

Petty Officer 3rd Class
Joined
Dec 31, 2010
Messages
85
Re: 1970 chrysler 55 outboard not circulating water and leaking drive oil.

all good points (incl. limits on running in a barrel). When replacing an impeller on my 10hp, I was seeing some impellers (ebay, probably) with 10 vanes, or maybe more -- hadn't seen that before, or hadn't noticed. As RearAdmiral says, more might not be better if you have a choice. As I think R.A. is also saying, you want to be sure that the shaft key is in place so the impeller will spin with the drive shaft.

not sure about the flusher fit -- can cut a rubber flusher down to fit, unless there is no intake on the sides of the housing.
Theres no intake on the sides its on bottom straight above the prop.
 
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