johnson 40, starts but won't keep running

[starcraft guy]

I have a 1960 40 johnson it will start but only <br />run for a few seconds, And only with choke on, <br />when i open choke up a bit gas runs out the mouth<br /> of carb, Could float be sinking and not closeing<br />needle to seat,<br /> does not seem to get gas to heads<br /> any ideas<br /> thanks river run

 

[fireman 757]

Re: johnson 40, starts but won't keep running

You definitely have a carb problem. Get a rebuild kit and pull the carb. Replace the float and needle valve. Make sure you replace the seat for the needle valve too. To set the float is should be level with the carb turned upside down. Make sure that your high speed jet is clear.<br />This should get you back on the water. To prevent this is the future make sure that you run the fuel out of this engine after each use. I would also recommend running 2+2 or Stabil in each tank.

 

[JB]

Re: johnson 40, starts but won't keep running

Wow, River Run! Strange set of symptoms!<br /><br />Usually if an engine has to be choked to stay running it is short on fuel. If yours starts dripping fuel, it obviously isn't short on fuel.<br /><br />There may be trouble somewhere else.<br /><br />Check compression.<br />Check spark for hot, blue arc at least 1/2".<br />Pull the carb and inspect reeds.<br /><br />If none of the above reveal any problem, overhaul your carb, with attention to jets for gumming and float setting. There may be something wrong in the float bowl that is both preventing the jets from feeding fuel and letting too much fuel into the bowl.<br /><br />Let us know what you find.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

Thanks Fireman, and JB,<br /> I will follow your advice and let you know the out come, should i soak carb parts in ( gunk)?<br /> thanks again <br /> river run

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

Carb kit on the way,It will take about a week to get to me,I took of carb cleaned and set float, The high speed needle, and low speed needle are all afloat ,will not stay in one place,The motor did start but ran on one cylinder, no fire to top <br />plug, are there points or what under flywheel?the old ran rough ,but i have hope for her<br /> thanks river run

 

[fireman 757]

Re: johnson 40, starts but won't keep running

I would not soak carb in any cleaner unless you have ALL the plastic parts out (if there is any). It will damage them. Use straight gas and a light brush, such as a toothbrush. Just make sure you get the high speed jet clean.

 

[JB]

Re: johnson 40, starts but won't keep running

Hi, River Run.<br /><br />While I agree wholeheartedly with most of Fireman's advice, there are 2 items that I prefer other approaches on:<br /><br />1. Do not run your carb dry. It is very bad for bearings and cylinder walls. It is better to drain your carb bowl after shutting down.<br /><br />2. There are other, safer solvents to use to clean carb parts than gasoline. They are usually labeled for carb cleaning.<br /><br />Good luck.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

Thanks guys <br /> Is there points under flywheel ?Iam not geting fire to top plug,The motor did run on the bottom <br />cylinder, rough but ran ,I have hope for the old girl<br /> river run

 

[Rex]

Re: johnson 40, starts but won't keep running

pull the flywhell and check the two sets of points<br />but first check for spark on #1.<br />same thing on a 67 33hp. Just needed to set <br />the points. Then it run great.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

Thanks Rex<br /> I will try that ,What should i set points at?<br /> river run

 

[fireman 757]

Re: johnson 40, starts but won't keep running

.20 Also check your coils before you pull the flywheel. Could just be a bad ignition coil.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

,Thanks fireman,<br /> i just came in from pulling flywheel mist your last post,anyway how to i check coil and points with flywheel off? things look good under there clean no burnt marks, I can put flywheel back on and pull start , then what ? I was geting fire to bottom plug and motor did start and run, when it was running i chacked top plug for fire there was none is there anyway to check fire at points with flywheel off? I turned crank and watched for spark was none, I need flywheel on for that don't i? Thanks again river run

 

[fireman 757]

Re: johnson 40, starts but won't keep running

You need to put that flywheel back on and torque it down GOOD. I use my air impact set on three and let it tighten until the impact barely turns. I don't know the proper torque. Check a manual. To check the coils swap the wires and recheck your spark at the plugs. If you get spark on the other plug then you have a bad ignition coil. Replace it and you should be on your way.<br /><br />To reset your points put the nut back on and turn the crank with your socket until you get the points to fully open on the top of the shaft. You will see that the shaft is offset on one side. Set your points when they are on the fat part of the shaft.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

Thanks Fireman <br /> Let me get this right,Do i set the points to.20<br />when thay are open and cam lobe is at the high point?coils are under flywheel do i just change sides befor putting flywheel back on? <br /> Thanks Fireman<br /> river run

 

[fireman 757]

Re: johnson 40, starts but won't keep running

Set the points to .20 when they are open. This would be on the wide side of that cam. Your ignition coils are on the outside of the engine. Your spark plug wires run into them. When you reset the flywheel make sure that you have no wires sticking up and that it does not make contact with the drive or charging coil underneath. They make a ring to place on them if you have taken these coils off. The drive/charging coils under the flywheel rarely go bad. You probably have a bad ignition coil. They are about $40.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

hi fireman and all<br /> Ok now i'm lost for sure, I pulled flywheel<br />cleaned and set points at .20, Put coil from # 2 over on # 1 motor did run on #2 with both coils still no fire #1,All i have are the two coils under flywheel, plug wires go from these coils <br />to plugs ,I gon't see any coils on outside of motor, It ran on #2 befor i pulled flywheel ,after i but # 2 coil on #1 it still ran on # 2 with no fire to # 1, When motor was running on # 2 i checked for fire at #1 plug it jumped fire once then nothing<br />what can i do next?<br />Thanks ever so much guys<br /> river run

 

[JB]

Re: johnson 40, starts but won't keep running

Howdy, RR.<br /><br />I think someone overlooked the fact that your engine is a 1960, which uses a magneto ignition. Your only coils are under the flywheel.<br /><br />Your explanation above is confusing. <br />Did you really set the points at .20, or is that a typo? Points should be at .020.<br /><br />When you switched the coils, did your trouble switch or not?<br /><br />Replace both condensers. They are cheap.<br /><br />Let us know.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

Hello all, and thanks Jb,<br /> points are set at .020.( typo)last meg,<br /> When i switched coils nothing changed,<br />Still no fire to # 1, both coils are good as they<br />ran motor on #2, I will replace condensers ,I will have to order them it may take awhile to get them, In the meentime should i switch condensers<br />to see if i can get fire to #1<br /> I realy apperciated all your time and help guys,<br /> Thank you all <br /> river run

 

[fireman 757]

Re: johnson 40, starts but won't keep running

Sorry for the typo. I slowed you down. Could very well be the condensers. Have you tried new plugs since you have done all the other stuff? Old plugs could be washed. You can try switching condensers while you wait but I have a gut feeling this is not the problem. However, I'm stuck too. I'll have to think about it and go look at my early '60's engine.

 

[starcraft guy]

Re: johnson 40, starts but won't keep running

Thanks fireman,<br /> The plugs are new, Both will run motor on #2,<br />As will both coils, there seems to be abit of play<br />on the plate the coils and points sit on,both sets of points look good ,I will switch condensers<br />just to see what that does,I do alot of work on old cars rebuilds and such some times i find that the points ground out , could this maybe something that i should look at?<br /> thanks again<br /> river run