71 Johnson 9.5hp

[Skredsvig]

I recently acquired a 1971 9.5hp Johnson. I was out running it today and I am having a few issues with it. I am new to 2-strokes so excuse me if I sound ignorant.

1. On the front of the carb there is a hole that faces towards the flywheel and when the motor is running fuel is spurting out. Is that normal? If not what causes it?

2. for about the first 10 minutes it ran, it seemed to run fine, then it started bogging down and would not obtain full rpm anymore. Ideas?

3. It does not want to run while the cover is on, but if I remove the cover it runs with above problems.

Do I need to rebuild carb? If so where can I get the rebuild kit? Where is a good place to get parts? Online?

Thanks.

Paul

 

[ezeke]

Re: 71 Johnson 9.5hp

Fuel should not run out of the hole facing the flywheel . It is doing that because your float valve is not working as it should.

There are several places where exhaust can enter the engine compartment and cause the engine to die. Most of the causes are more of a problem when running the engine in a bucket - So leave the cover off while you run it that way.

Keep checking the cylinder head with your fingers. You should be able to keep your fingers on the head for no less than or more than 3 full seconds. You should have water spitting out of the exhaust relief any time the motor is running. Be sure that the water in your bucket is above the water pump when you start the motor and all of the time that it is running.

Get the carburetor kits from your BRP dealer so that you get the new float. The floats are made of cork coated in shellac. Shellac is dissolved by the alcohol in our newer fuels so that they don't last very long.

The floats for the 9.5 are cork- they don't come any other way so far. The kit # is 0382048.

You can get most parts from your local dealers and save the shipping costs. : http://dealerlocator.evinrude.com/en/410000.shtml

 

[jbjennings]

Re: 71 Johnson 9.5hp

Howdy,
I'm thinking:

1. The not running with cover on is either an exhaust leak that's letting exhaust into the cover, or you're running it in a barrel without a fan to blow the exhaust away from the motor.

2. the fuel leaking out is because your float is either water logged, misadjusted, or your float valve is sticking.

3. The bogging is either a dirty carb and sticking needle valve/bad float or you have a coil going out and you're losing spark on one of the cylinders.

Suggestion: clean the carb and see if the float is cork. If it is clean it, dry it, and redope it with some fuel proof dope. Polyurethane works too, but I don't like it. clean all the passages in the carb and pay particular attn. to the float needle and seat.

If you're running it in a tank, use a fan to blow away the exhaust and see what happens. If it still won't run without the cowl off, then you almost positively have an exhaust leak.
I hope you're rubber engine mounts are good!:redface:

Good luck,
JBJ

 

[jbjennings]

Re: 71 Johnson 9.5hp

Sorry,
Ezeke types quicker!

Good places for parts are here at iboats, laingsoutboards.com, etc. You can look at crowleymarine.com at their parts diagrams and get some part numbers, and then come back to iboats to give them your business....
Later,
JBJ

 

[Skredsvig]

Re: 71 Johnson 9.5hp

Ok, so I took off the carb and checked the inside. Not sure what is the needle valve? Checked the cork float and the cork has a lot of dark coloration on it. I gave the carb a good cleaning.

Where is the exhaust relief? Same as pee hole?

I have not run it in a bucket as I have read it has a hard time due to exhaust.

If I do have an exhaust leak what gasket or part would be more than likely culprit?

I put in brand new spark plugs gapped at .020. The one question I have about them is I have read in the forums to use j6c and when I got the motor it had 8jc spark plugs in it so replaced them with j8c. Is that a problem?


I appreciate all the help!!!!!!!!!!!!!!!1

 

[ezeke]

Re: 71 Johnson 9.5hp

Needle valve usually refers to the adjustable needle that adjusts the lean/rich setting on the 9.5.

The float needle (which should be connected to the float) will close when the float rises, preventing the carburetor from flooding.

When you rebuild the carburetor with your new float, be sure that the needle is connected to the float arm as shown when you click the thumbnail below. The clip will come with the new kit.

.020 is the setting for the points not the spark plugs.

The standard plug for the 9.5 is the J4C. It should be set at .030. If the engine is badly worn and has low compression, you may want to use a J6C. The J8C is way too hot a plug for the 9.5.
http://www.boatsetup.com/Spark Plug Chart 2007 BRP.pdf

The exhaust relief is the rubber outlet that is mounted between the engine and the lower cowl at the back of the motor. It is also one place that exhaust can enter the engine compartment if the rubber is bad.

 

[Skredsvig]

Re: 71 Johnson 9.5hp

I cleaned and checked everything again. The float still has a clear glossy stubstance encasing it. I am assuming this is the coating. I cleaning the pin that holds that float on, it was dirty. I also found that the clamps for the fuel hoses were loose so I tightened them thinking maybe that could cause other problems. I have it all put back together now. I will hopefully try it tomorrow. Curiosity questions. Besides the exhaust relief is there other places it can leak? I have been told by others to drill a hole in the cowling near the Carb. Is this a good idea? I am also thinking about replacing fuel lines. Is there a part number for the hoses? What is a good prop size for the motor? The prop is in need of replacement and has no size on it.

Thanks again for the help.

 

[ezeke]

Re: 71 Johnson 9.5hp

The OEM propellers are listed on the gearcase diagram for your specific motor: http://epc.brp.com/default.aspx?brands=ej&lang=e

You can find Michigan Wheel aftermarket propellers here: http://boatpropellers.iboats.com/?dz=36857

The exhaust can leak from: missing or damaged seal between the waterpump and the driveshaft tube; from missing or damaged seal in the midsection through which the water tube and shift rod pass; from missing or damaged large exhaust housing seal between the inner exhaust tube and the outer; from a bad gasket between the powerhead and the adapter plate; and from bad gaskets in the exhaust covers.

You can allow for more air to enter the engine compartment by drilling behind the hand grip; it will be less obvious. However, it may make the problem worse by providing more circulation for the rising exhaust fumes. The best fix is to find the leak and repair it.

 

[Skredsvig]

Re: 71 Johnson 9.5hp

WOW. Thanks for the help. This place is a wealth of knowledge!!!

 

[Skredsvig]

Re: 71 Johnson 9.5hp

So my local dealer happened to have a carb rebuild kit, needle, and fuel pump kit in stock. I replaced them and had the carb with me so the mechanics looked at it and said the carb was spotless and the needle and everything looked good, i still replaced the needle. tested it out on the water afterwards and The fuel is still spurting out the hole in the carb. Also, it is still letting exhast somewhere. So i tested it with the cover off and it ran great, then i slowed down to an idle and when i tried to pick up speed, it would only get about half speed and rpm with the throttle wide open. Not sure why. I was surprised though as it started on first pull today instead of the normal 5 or 6. So now I am at a loss as to why it is spitting fuel out the hole in the carb. I also do not know what is causing it to not get full power after a fe wminutes of use.

 

[F_R]

Re: 71 Johnson 9.5hp

It is spitting fuel because the float valve is not doing it's job. What needle did you replace? It is not rocket science. The float rises and closes the needle & seat valve. For some reason it is not closing.

The flooding carburetor is enough reason for it to run poorly. Your 1/2 speed issue could mean it is running on one cylinder. Check for spark and try some new spark plugs.

Those motors are notorious for smoke inhalation. The common causes have already been listed. The only easy ones to fix are the exhaust relief hose and the seal on top of the water pump. If it is one of the other reasons, get ready for a mind-boggleing repair job or get somebody else to fix it for many $$$$$.

Unfortunatly, it would seem like you have multiple problems. That makes it tough to try to tell you how to fix it. Unless you are very mechanically inclined, thsi is not a do-it-yourself motor.