need your help w 1953 johnson

[Lund_LAB]

So my winter project this year was completely tearing down and rebuilding an old 1953 jw-10 johnson 3 horse motor. I replaced all the electrical components, cleaned up everything else (it sat in a barn for 30 years prior) and had the carb professionally rebuilt. Now with everything put back together, it will not fire. The spark plugs are sparking blue and appear to be wet with gas when i pull them out of the cylinder so i cant figure out what is wrong. I currently am using a rich mixture of about 20:1 or so. The spark plugs I obtained are from the local parts store and are longer than the originals but seem to be working fine. I dont know if either of those could be the problem but if anyone has any ideas id be very greatful to hear them cause im stumped. Thanks

 

[jbjennings]

Re: need your help w 1953 johnson

Myself, I think you need to get a $6 spark tester at autozone and see if your spark will jump a 1/4 inch gap. Are your points adjusted .020? Also, get some J4C or J6C spark plugs while you're there. I suspect you have weak spark.
Also, have you tested the compression on that motor? What was it?
Good luck,
JBJ

 

[JB]

Re: need your help w 1953 johnson

If all else fails go to the Engine FAQs Forum and do "Outboard won't start".

 

[Woodstock60]

Re: need your help w 1953 johnson

If the spark plugs seem a bit long that could be your problem. longer plugs will spark when out but if the piston hits them it could be trouble.

 

[Lund_LAB]

Re: need your help w 1953 johnson

thanks a lot for the info. I swapped out the other spark plugs which were autolites and put in some champion j8c's and also gapped the points to .020 and she fired up for a few seconds... but i need to tune the needles on the carb now because gas is leaking out of them. But thanks again for the help

 

[JB]

Re: need your help w 1953 johnson

J8Cs?? Why??

That engine calls for J6C, as JBJ suggested. If you can't get J6Cs, use J4Cs.

 

[Lund_LAB]

Re: need your help w 1953 johnson

Lol, i just went out real quick and J8Cs were all i could find so i figured i would try them for only $3.80 for the pair. Would they make much of a difference? I will go out and try to find the right set though when i find the time.

And thank you very much for the help JB, ive read some other reviews and im finding you are the main source of help for everyone having starting problems... I appreciate the patience

 

[freddyray21]

Re: need your help w 1953 johnson

J8 will work, but a J4 or a J6 will give a hotter spark. If you need short plugs get the CJ4 or CJ6.

 

[JB]

Re: need your help w 1953 johnson

Actually, the J4C is a cool plug, the J6C warmer and J8C a hot plug. Spark temp is pretty much the same.

The plug reach is critical because its operating temp depends on heat transfer to the cylinder head. If the plug reaches beyond the threads it will run far too hot and risk preignition.

 

[Lund_LAB]

Re: need your help w 1953 johnson

Thanks for all the help guys... shes is running like a dream now with the J6Cs. This is a stupid question i realize, but where does the water exit the motor? i know the pump is working but there is no stream coming out. Does it exit with the exhaust?