Home › Forum › Ask A Member › 1948 Neptune Mighty Mite A1 starting issue help requested
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garry-in-michigan.
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March 24, 2017 at 9:33 pm #6604
OK..I got great spark, good compression, I took the carb apart 2 times and cleaned it. The float is NOT sticking. I can get it to start but not run for more than a second or two. I am not sure where the needle adjustments are supposed to be so I an guessing on that.
I put my drill on the flywheel with a 3/4" socket and can get it to spin nicely, The float needle comes out of the top as it should. When I spin it over I can hear it firing but when I remove the drill the motor stops after about a second. I can put my thumb over the intake in the carb and that helps but still it won’t stay running. To me that means it is not getting enough gas so I open the needle vales 1/4 turn at a time but the motor still won’t stay running.
I have got good fuel flow to the carb. when I remove the screw under the float bowl, clean gas drains out. I see no dirt anywhere. When I cleaned the carb, I made sure all holes and orifices were clean using spray carb cleaner.
I am at a loss. Any advice would be appreciated.
Thank you
BillMarch 24, 2017 at 10:46 pm #54826would sound like there is stil some crud blocking passages in the carb. might also watch the pin on the float could be getting gas but not enough flow to the carb to keep it going.
Doug
how is it motors multiply when the garage lights get
turned off?March 24, 2017 at 10:59 pm #54828Check your spark plug to see if it is wet with fuel mix. If dry, put a little fuel in the spark plug hole. See if it will fire.
March 24, 2017 at 11:32 pm #54829John: It does fire. it just won’t run for more than a second or two at most.
March 25, 2017 at 1:59 am #54841A problem on the very small outboards the are either hard to start or will not run at idle is poor crankcase compression. This likely due to worn crankshaft bearings (bushings). Check for lateral movement of the flywheel, any discernible movement would indicate worn bearings. This condition not easily remedied, absent a competent machinist. A possible "band aid" , try running a very rich oil mix, like 8 to 1 and see if the condition improves.
Joe B
March 25, 2017 at 1:25 pm #54861Thanks Joe…can you tell me where the carb needle adjustments should be set to?
March 26, 2017 at 2:53 pm #54927One turn out on the main, 3/4 turn for the idle.
If you have too many, AND not enough, you're a collector.
March 29, 2017 at 2:05 pm #55145OK…got it working. Turns out, there were two issues. First there are two seals on the crankshaft. One of the seals (on top) was missing completely. The clip to hold the seal was there but no seal. So, I made one on my 3D printer. Second, there was a leak in either the head gasket or a small crack in the cylinder head as water was getting in the combustion chamber. I had another cylinder so I replaced it.
Now it runs!
Thank you all for your advice and assistance
Bill.March 29, 2017 at 6:29 pm #55153Bill, glad you got the old Neptune running.
I’m curious on how one makes a seal on
a 3D printer. I know nothing much about
them, but don’t they make "plastic" items?Prepare to be boarded!
April 1, 2017 at 9:06 pm #55328Yes buccaneer they DO make plastic. They also make rubber, wood, some metals, nylon and even chocolate. Yes, I said chocolate. If you go to my website http://www.billrauscher.com/outboards, I have items under OMC parts like the rubber bumpers for the shrouds as an example. I have made other parts as well.
Not a lot of people have 3D printers yet but it is a growing idea. Once you get the printer, you then need to learn a CAD program to be able to make stuff. More toys…more fun 🙂
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