1972 johnson 9.5

[Freeves]

This motor cranks with one pull with choke on then when choke is turned off it starts coughing and when you open up throttle it is slow to catch up. Has anybody got any idea what might be causing this?

 

[Rick.]

Re: 1972 johnson 9.5

At idle, try turning your slow speed needle counter clockwise an eighth of a turn at a time and see if it improves. If not you may need to clean your carb. Best of luck. Rick.

 

[Freeves]

Re: 1972 johnson 9.5

I have on already rebuilt carb. Could this have anything to do with ignition? On the crankshaft there is top then beside it there is a m which should I line the points up with when i set them? can anybody walk me through settn points ? Any info will be greatly appreciated.

 

[bktheking]

Re: 1972 johnson 9.5

Points info

http://forums.iboats.com/showthread.php?t=294072

 

[Freeves]

Re: 1972 johnson 9.5

I took boat to lake the other day it was running fine, stopped at first spot fished a while then we fired the motor up again and were headed to the next fishing spot all of a sudden the motor acted like it got in a bind and died. I tried to crank it again there was so much pressure on the motor i could barely pull the start rope .So I left it alone unti we got home. When we got there I pulled off flywheel , the four scews holding the plate on had backed out, one had dug into the flywheel that is what he pressure was . Since then when you choke it it will still crank first pull then when you turn the choke off and let the rpm's die down it will sound like its sneezing and coughing, when you open the throttle up it takes a good three to four seconds to catch up, alot of times it will just die if you ket the rpm's get to low. maybe this little extra bit of inf0 will help any input will be greatly appreciated.

 

[bktheking]

Re: 1972 johnson 9.5

I had these screws backout too on my 9.5, once they do they bind the throttle and you can't rotate it or in your case the flywheel. If you want to stop that from happening use some loctite on the screws when reinstalling.

Regarding the RPM issue, have you tried adjusting the low speed jet on the carb?

 

[Freeves]

Re: 1972 johnson 9.5

I have tried moving slow speed adjustment. Started motor up today run it for a little while and it finally started running right I killed it out; then a little while later started it again it was missing then it would straighten out and run good then it would go to missing again . I dont know what is going on.

 

[bktheking]

Re: 1972 johnson 9.5

Put a timing light on the wires and see if you are dropping a cylinder.

 

[Freeves]

Re: 1972 johnson 9.5

Could you please explain this to me?

 

[bktheking]

Re: 1972 johnson 9.5

Sure, an inductive timing light flashes with every spark pulse to the plugs, any auto store will sell cheap inductive timing lights. Put a timing light on each plug wire and run it, if it's missing due to intermittant spark you will see the light stop and start and not be consistant.

 

[Freeves]

Re: 1972 johnson 9.5

Thanks for the info I will get a timing light tommorrow and check it out. If I am missing a cylinder what would be the next step?

 

[bktheking]

Re: 1972 johnson 9.5

Pull the flywheel and inspect- look for cracked coils, dirty points (they need to be shiny and adjusted properly)and bad plug wires are the common issues. If you don't have a flywheel puller you will need one as well. Torque wrench too for retorqing the flywheel nut, lots of tools needed to work on these little beasts.

Carb could also be causing a lean sneeze at idle but that usually dissappears with throttle, if the miss occurs at all rpm's then it's more than likely ignition.

 

[Freeves]

Re: 1972 johnson 9.5

Thanks for all the info I will get back on it tommorrow and see what happens.