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Johnson 9.5hp (9r73) outboard engine interrogation

E

electroman

New member
Hello everyone. I'm repairing a 1973 Johnson outboard (9r73) without serial number and I'm already at the reassembling but fell on my but when I realized that the middle exhaust plate was missing. I pretty sure that I didn't disassembled it or lost it. What I have instead is a small exhaust valve on the exhaust manifold exterior plate at the bottom left(we can see the two holes on the diagram). My question is how can I confirm that my engine doesn't need that middle plate with the two exhaust valves? Thank you for your help and have I nice week. Sly from Montreal Quebec Canada.
 
You will have to post pictures !-----There are no " exhaust valves " on a 2 stroke motor.-------Perhaps you are mis-interpreting something.There is a plate on these engines with reed valves which are part of the " intake system " , of course it must be installed. Without the reed valves the motor can not run.
 
Sorry about that everyone. It's the intake manifold and not the exhaust. It's call leaf plate assembly but it can be ordered separetly.
 
The assembly appears to be available new.Ordering the parts seperately is expensive !!-----Not worth looking for a used one.----See your local dealer.
 
I will try to be as clear as possible. My problem is located on the the intake manifold. During the disassembling, it appear that there was a critical part missing which is the leaf plate(middle plate with the valves or sort of). Can you believe that it used to run anyway. Not correctly but it worked. Now, here's my question. On the diagram of the intake manifold things are not showed like the little valve that goes on the bottom left of the housing and the sort of filters that are put inside of that same part called housing. But for my problem, do I need to buy that leaf plate (middle plate /assembly)? How do I know that my engine needs that part? Would it be possible that the one I have doesn't need one? I don't think so. The engine number is 9R73 Johnson 9.5hp.
 
The first thing that needs to be done is to post the model # of the motor to establish the correct year !---------Go to the parts section ( above yellow line on this page ) -----Remember that the engine block may have been replaced with an older unit.---------Find the part # s of the parts that are missing.------------------If the main plate with reed valves was missing then the motor would not run !!----------------HINT-------Older motors had reed valves in a different location.
 
I did what you told me and I confirm that my model number is 9R73B (1973). I can also confirm that the middle plate with the reed valves was missing from the engine. I will order it and go on with reassembling. If anyone has any other tips with my problem feel free to contact me.
 
A 2 stroke engine can not run with the reed valves missing !!!-------------I do own more that one of these motors and worked on lots more as well.---------Any pictures of the manifold with carburetor removed ??
 
Photos de Nokia C6-00 002.jpgPhotos de Nokia C6-00 003.jpgPhotos de Nokia C6-00 004.jpgPhotos de Nokia C6-00 005.jpgPhotos de Nokia C6-00 006.jpgPhotos de Nokia C6-00 007.jpgAs you can see, I've being able to put photos in that reply. Hope that will help get all infos I need. Thank you again for your time.
 
The reed valves are just beneath the carburetor on the motor that you have --------------IT IS NOT A 73 POWERHEAD !!-----------Just like was mentioned before.------------The powerhead is a 1971 or older -Trust me !-----------You might want to cancel the order for the 72/73 reed plate that was " missing "
 
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Yeah, I already prepared the block to be reassemble. However, at first I looked at some videos on Youtube showing the exact same casing engine as mine and the were all saying that it was a 73 model. That's the reason why I assumed it was a 73. By luck, all the parts I ordered before talking to you were to be installed in 67 or 68 to 79 models. Only one gasket, the second one which I thought was going on the middle plate on 73 model. But Like you said, it is important to make shure that we are in front of the right infos in regards of the engine. Thank you for your time and advices.
 
Post a picture of your motor including the cowling ( if unmolested ) and we can tell you what year it is.------The 9.5 was made from 64 to 73 only.------------Nice fishing motors.-----------You have of course taken the lower unit apart for inspection !-----------You can not believe everything you see on U-tube.----------I see motors advertised all the time and lots of times the seller is out by 10 years on the model.
 
The engine block is obviously older going by the colour of the paint.--------------The bottom half of the lower unit is also from another motor, which is not a good thing since the bottom and top are " matched " when machined as an assembly.----------You may be lucky and get away with that.
 
I extracted the seal with a bearing extractor. Wasn't easy but got it anyway. It was in very good condition so I cleaned evrything an reinstalled it. I woul say that more than 95% of the parts were in perfect condition and the repair cost wasn't that high (around 300$ with shipping and fees and taxs). It will have been a great experience for me to understand the fonctionnality of small gas engine. Soon I finish that project I will be able to use it. Let you all know if it went well. Thank you.
 
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