Getting started: my first (real) boat! 1979 Chrysler with an "issue"

srimes

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Mar 28, 2010
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Hi y'all,

I just bought my first real boat:D: a 15 foot tri hull ski boat with a 70 hp chrysler OB "project boat" for $900. It started right up in a bucket, but the previous owner says it doesn't run right at full throttle. I haven't taken it out yet so this is his description of the issue: It starts and runs good under part throttle up to about 20 mph, but more than that it starts surging. The mechanic said it looks like a carburetor issue and he can fix it for $150-$200, and other than that the engine looks good. The guy I got it from seems honest, but not all that mechanically experienced.

I have a bit of experience working on cars: rebuilt carbs, rebuilt an engine, set it on fire (twice :redface:), you know, backyard mechanic stuff :cool:. I have basically no experience with outboards. I've only driven an outboard boat a couple times, much less worked on one. Any suggestions for getting started? I just order a "chrysler outboard" manual from amazon: http://www.amazon.com/gp/product/0892875518/ref=ox_ya_os_product

I looked through the faqs and the "testing you boats fuel system" is one I'll use for troubleshooting this issue. Anything else y'all would suggest?
 

foodfisher

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Sounds like you have it covered. Surging would be a fuel problem.
 

srimes

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Mar 28, 2010
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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

OK good, thanks. I was looking over the motor today and noticed that where the fuel line goes in to the motor it gets a little pinched. Not completely shut, just half way or so. Is this normal? Is it supposed to have soft line going through the grommet, or should it be hard line (or something) there?
 

foodfisher

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Semi rigid. No sun. Maybe the ethanol gas we have today has deteriorated yesterdays fuel line. If so you will need to check entire system for disentegrated fuel line deposits. A filter is needed and new lines.
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Semi rigid. No sun. Maybe the ethanol gas we have today has deteriorated yesterdays fuel line. If so you will need to check entire system for disentegrated fuel line deposits. A filter is needed and new lines.

Hmmm. The fuel line to the motor isn't stock, it has a newer universal plastic tank and hose, which looks like this (for all I know it came from walmart): http://www.iboats.com/Universal-Fue...2336826--**********.706646132--view_id.686406

The fuel hose looks like it's in good shape, it's just soft and flexible and pinches where it enters the motor housing. What kind of line should I use there?

The fuel line on the motor is black and much stiffer, much like automotive fuel line, but it is unmarked. I was thinking of replacing it just for good measure as there isn't that much of it, but it doesn't look bad, no cracks anyway. Also, on the carbs the hose clamps are the single wire spring type and aren't very tight. I can easily twist the section of line between each carb. I didn't see them leaking though. Is that the right kind of clamp? Maybe the previous owner changed the lines and used the wrong clamps.

The P.O. said he changed the fuel pump and I believe the filter that's on the pump. I asked if he rebuilt the carbs and he said no, but he cleaned them.
 

Frank Acampora

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12,004
Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Almost certainly a fuel problem!

Don't take anything for granted. Buy a diaphragm and gasket for the fuel pump and change them. Re-clean the carbs. WD 40 does a good job. Check the fittings on the tank and see if there is a strainer inside the tank that may be clogged. Install a cheap, plastic, disposable fuel filter BETWEEN the fuel pump and carbs, do not depend on the strainer on the fuel pump.

And NO, there should be no kinks in the fuel line--aftermarket or not, does not matter. 5/16 to 3/8 diameter will supply all the engine's needs.
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

When you say "clean" the carbs, does this simply mean spraying cleaner (like wd40) in them, or does it involve partial disassembly, like a partial rebuild?

I think that maybe the motor grommet is sized for 5/16" line from the tank instead of the 3/8" which is crammed in there now.
 

Frank Acampora

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Yes, I mean remove the carb, Take off the bowl. Remove the float and inlet needle and remove the low speed needle. Make sure you note the setting before removing--ie. 3/4 turn out or 1 turn out etc.Clean the bowl with a Skotchbrite pad and WD, then spray WD into every hole. Run a pipe cleaner through the lower brass jet and run it through the thin brass tube from the bowl to the top of the carb. Make sure that the cleaner will shoot out of every hole. Don't worry! They are simple carbs, you will not need diagrams or instructions.

The hose clamps are ok but long ago. I started using nylon cable ties instead. They get tight enough, don't cut the fuel line because they can't be overtightened, and at a penny each, I just clip them off when I need to change anything.

If you already have 3/8 fuel line, leave it. Better excess capacity than not enough.

If you have a quick-connect fitting at the tank, check the spring inside the male fitting. Crap tends to collect there and restrict flow.
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Finally got it on the water for my first test run. Fun fun, I love it! :D

Starts great, idles great, and has plenty of power to jump out of the hole. It gets out of the hole and up to speed and runs like that for maybe 15 seconds, then it acts like I'm slowly throttling back. So I throttle back to idle, sit for a few seconds, and it's good for another 30 second run. Definitely feels like it's running out of gas, I had a truck that acted the same way until I put on a new fuel pump.

I did take the cowl off and pulled the fuel line out and reattached it to see if the pinch point was the cause. It seemed to run for a bit longer before it lost power, but it still happened. Ran the hose back in its place for another run and it did fall off more quickly. So it seams that the pinch is contributing to the issue but isn't the main cause.

I didn't have a vacuum gauge hooked up, I'll get around to that :redface:.

The previous owner said he put in a new pump (and I believe him), but could he have done it wrong?


It was fun to get on the water and scoot, even if it was only a 1/4 mile at a time :)
 

foodfisher

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Easy repair. Change the fuel pump diaphram and you'll know it has been done. Does "check's in the mail" or "a little tlc needed" or "trust me" fit the situation? Yes, could have been done improperly.
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Easy repair. Change the fuel pump diaphram and you'll know it has been done. Does "check's in the mail" or "a little tlc needed" or "trust me" fit the situation? Yes, could have been done improperly.

Yeah, I don't believe all I'm told :rolleyes:, but this kid seemed honest and not all that mechanically smart. He talked about how he was surprised that the fuel pump kit only had a membrane. He said he was expecting "a real pump." So I believe him on this, but he may have done it wrong.
 

huskerdaninva

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

You may want to look at the three check valves in the fuel pump housing. They can gunk up, become deformed/swollen, etc. Just something to think about. Good luck.
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Finally got around to messing with the fuel pump. It looked clean and the diaphragm wasn't torn, but it did look stretched and wrinkled. Plus, when I took it off the gasket behind it ripped so I went ahead a new kit. Check valves looked good too.

I also decided to add a telltale after reading the thread on it. So I hooked it up and started the motor to check the fuel pump and the telltale: no water came out :eek:! Water came out the exhaust holes on the leg like it does, but at most I could only get a few drops from the telltale when I blipped the throttle. Water does spray out the back, just not from the telltale:confused:. How bad is this:(?

Could this be why it doesn't hold WOT after 15-30 seconds?
 

wickware

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

?Install a cheap, plastic, disposable fuel filter BETWEEN the fuel pump and carbs, do not depend on the strainer on the fuel pump.?

1. Are filters between the fuel pump and carb ?mainly? to catch parts of a bad diaphragm or trash from the tank? My disposable filter has always been between the tank and fuel pump. It verify the flow of fuel to the fuel pump if needed w/o pulling the cover to see the bowl. I possibly need 2 filters.

2. Is the attached stretched fuel pump?s diaphragm a good example of one that ?will cause problems or not necessarily?? This is one that was posted vs mine.

JOW
 

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srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

OK no replies yet, but I guess I'll go ahead and change the impeller. The motors a 709h9a (I think) so I found the impeller:
http://www.iboats.com/mall/partfind...gd_poid=110819&gd_row=12&**********=454718947
but which gasket do I need? This:
http://www.iboats.com/Water-Pump-Ga...5170543--**********.454718947--view_id.173469

or this?

http://www.iboats.com/Water-Pump-Ga...5170543--**********.454718947--view_id.173475

It'd be nice to order before taking it apart so I don't have to wait another week. Thanks.
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

So I pulled the lower unit and pump this evening (this thread is turning into a monologue instead of a discussion).

1) There was an oil leak from the weep hole by the water pump. Sorry for the dark picture, I tried to point it out. The oil looks like a shadow, but it's the jet black splotch below the hole. Also, I noticed water running out of this hole the last time I ran it. Is that bad? What would cause this leak?

attachment.php


2) When I removed the lower unit I couldn't find a rubber crankshaft seal. The steel collar was on the drive shaft, but when I tilted the motor down nothing fell out and I looked up there with a flashlight and didn't find it:eek:! What happens if you run without it, and where can I find a replacement?? Could this be the cause of the oil leak?

3) the impeller didn't look so hot:
attachment.php


and there was no gasket between the housing and the lower plate. Should there be one? The housing looked good, but the lower place has a groove. Is this bad? Where can I get a replacement?

I know I ask a lot of questions, but I really appreciate the help.
 

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srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

hello? anyone?
 

pwilke

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

Replace that impeller, it looks like crap, probably hasn't been replaced in a long time. Make sure you install with the fins bent correctly. When you say housing and lower plate do you mean between the tower leg and the lower unit? if so there is no gasket there it just comes together when you bolt it back on. What looks like an oil leak to you coming out of that hole is probably just exhaust crud mixed with a combination of water. How does your lower unit gear oil look? If it is milky looking it is means that its getting some water in it. As far as the crankshaft seal I believe some of the driveshafts might have had an o-ring at the top but then again this could be just on OMC motors, I'm not sure. You might not be able to see the seal and its still up there. You would be surprized how many people re/install the drive shafts and don't put the shaft seals back on, then there lost and no one knows the difference. Your not going to leak oil out of the crank. You can look in your manual when you get it to check out the crank seal subject.
Good luck..........
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

. When you say housing and lower plate do you mean between the tower leg and the lower unit?

No, I mean between the impeller housing and the plate that caps it off, there's no gasket there. There was a gasket between the plate and the lower unit.


.What looks like an oil leak to you coming out of that hole is probably just exhaust crud mixed with a combination of water. How does your lower unit gear oil look? If it is milky looking it is means that its getting some water in it.

I dunno. Guess I should look... I

. As far as the crankshaft seal I believe some of the driveshafts might have had an o-ring at the top but then again this could be just on OMC motors, I'm not sure. You might not be able to see the seal and its still up there. You would be surprized how many people re/install the drive shafts and don't put the shaft seals back on, then there lost and no one knows the difference. Your not going to leak oil out of the crank. You can look in your manual when you get it to check out the crank seal subject.
Good luck..........

Well that's good to hear. Glad it isn't all that important. Thanks.
 

srimes

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Re: Getting started: my first (real) boat! 1979 Chrysler with an "issue"

So I took it out again yesterday to see if the new fuel pump and impeller fixed the problem. It didn't:(. Still did the same thing so I hooked up the vacuum gauge+clear hose to the fuel line before the pump. It didn't pull much vacuum and I didn't see any bubbles accumulate in the hose, but I couldn't watch it well while driving.

So if the issues is a fuel problem it's somewhere after the fuel pump inlet. Since I replaced the pump diaphragm I guess then next step is to pull the carbs, right?

Any chance this is an ignition problem? How would I check for that?
 
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