I’ve got a 58’ 7.5hp and I love it. Also a 54’ 10hp that’s doing the same running on one cylinder. Definitely got a good inside look in this video on what to do when I try and diagnose it. Always great to see another old soul in his element. Great stuff bud. Keep it up!!!
So, I didn't really clarify it well in this video, but it actually wasn't running on one cylinder, it was just running extremely rich from the mixture settings being so far out of adjustment. (It sounded like it was running on one when it first started up). The big things from what I've seen that need done on these motors when they've sat around that causes them to run poorly are: 1) Carburetor - clean, replace seals/gaskets/float (if needed). Even if the carburetor isn't dirty, I've seen the original floats start to soak in fuel and not work anymore (you'll know this is a problem if the carb starts overflowing). On the original floats, the ethanol in today's fuel would eat through the protective 'shellac' on the outside. Later cork floats were more resistant to this, and then later carb kits had polymer ones in them. 2) Ignition - original coils will typically be cracked. The motor will run, but lose power and misfire under load. This is very obvious and easy to see from the inspection hole in the flywheel. Points are also many times dirty and/or out of adjustment. Ocassionaly consders bad as well (although I haven't seen as often). Many times if it's just dirty points, you can reach in with an ignition file and clean them up enough (and adjust gap) to get good spark. I actually have an early 1950's green 10 HP Johnson (slide throttle with center shifter) that wouldn't go full throttle and felt like it wasn't running on both cylinders under load years ago. Tried everything to fix it and it drove me nuts. I finally figured out that the center flat rubber gasket/seal on the carburetor bowl was flattend/bad and wasn't sealing off properly, so it was basically dumping excess fuel in to the main circuit under load and running it too rich. Once I put a new rubber washer in there, it ran fine. Good luck with yours, thanks for the support and comment!
Thank you so much! There wasn't a whole lot of substance with this one or anything in particular I showed working on with it (which I probably should have), but I was really happy with how the sound turned out capturing the motor noise. I'm a weirdo - I could listen to these old motors run all day long with a smile on my face :)
Ha, I saw that! I always poke fun at the lack of our success, but I'm honestly glad to see old outboard content getting a little love as it really needs more interest....especially from the younger crowd. (To that end, I was shocked at the 1000's of views the simple video I made running my MK75 around the lake has racked up). Thanks for the like, and have a Merry Christmas as well!
Mainly just by the sound - however, as you saw, I assumed it had a "dead" cylinder (no spark, not firing for some reason). What I found was that it was running REALLY rich due to the mixture screw being out. This either caused it to just run slow enough that it sound like it was on one cylinder. Or, one of them was fouled out / just rich enough that it wasn't firing. If any of this makes sense :)
@Steve-e4b it hadn't been started in many years, and the carburetor was out of adjustment. Started on one pull once cleared out and run, and she works like a charm on the lake now
I’ve got a 58’ 7.5hp and I love it. Also a 54’ 10hp that’s doing the same running on one cylinder. Definitely got a good inside look in this video on what to do when I try and diagnose it. Always great to see another old soul in his element. Great stuff bud. Keep it up!!!
So, I didn't really clarify it well in this video, but it actually wasn't running on one cylinder, it was just running extremely rich from the mixture settings being so far out of adjustment. (It sounded like it was running on one when it first started up).
The big things from what I've seen that need done on these motors when they've sat around that causes them to run poorly are:
1) Carburetor - clean, replace seals/gaskets/float (if needed). Even if the carburetor isn't dirty, I've seen the original floats start to soak in fuel and not work anymore (you'll know this is a problem if the carb starts overflowing). On the original floats, the ethanol in today's fuel would eat through the protective 'shellac' on the outside. Later cork floats were more resistant to this, and then later carb kits had polymer ones in them.
2) Ignition - original coils will typically be cracked. The motor will run, but lose power and misfire under load. This is very obvious and easy to see from the inspection hole in the flywheel. Points are also many times dirty and/or out of adjustment. Ocassionaly consders bad as well (although I haven't seen as often). Many times if it's just dirty points, you can reach in with an ignition file and clean them up enough (and adjust gap) to get good spark.
I actually have an early 1950's green 10 HP Johnson (slide throttle with center shifter) that wouldn't go full throttle and felt like it wasn't running on both cylinders under load years ago. Tried everything to fix it and it drove me nuts. I finally figured out that the center flat rubber gasket/seal on the carburetor bowl was flattend/bad and wasn't sealing off properly, so it was basically dumping excess fuel in to the main circuit under load and running it too rich. Once I put a new rubber washer in there, it ran fine.
Good luck with yours, thanks for the support and comment!
Awesome work brother! Keep it up love the content!!
Thank you so much! There wasn't a whole lot of substance with this one or anything in particular I showed working on with it (which I probably should have), but I was really happy with how the sound turned out capturing the motor noise.
I'm a weirdo - I could listen to these old motors run all day long with a smile on my face :)
Thank you for this video!
Sure thing, thanks for commenting!
joke is on you. you got 203 views at this point. I'm also gonna click the like button to push it further ;) Have a Merry Christmas.
Ha, I saw that! I always poke fun at the lack of our success, but I'm honestly glad to see old outboard content getting a little love as it really needs more interest....especially from the younger crowd. (To that end, I was shocked at the 1000's of views the simple video I made running my MK75 around the lake has racked up).
Thanks for the like, and have a Merry Christmas as well!
How could you tell it was running on one cylinder?
Mainly just by the sound - however, as you saw, I assumed it had a "dead" cylinder (no spark, not firing for some reason). What I found was that it was running REALLY rich due to the mixture screw being out.
This either caused it to just run slow enough that it sound like it was on one cylinder. Or, one of them was fouled out / just rich enough that it wasn't firing.
If any of this makes sense :)
If you have to pull it more than 3 times something is not right
@Steve-e4b it hadn't been started in many years, and the carburetor was out of adjustment.
Started on one pull once cleared out and run, and she works like a charm on the lake now