johnson 20/18 help please!!!

[henning_dt85]

Hi, I have bought a johnson outboard engine today, and the seller claimed that this is a 20hp. If this was a 20hp it would have been from 1966-67, but the model-number is not telling me that!!!! The modelnumber is FD-17, and from the list from evinrude or johnsons homepage that tells me that this is a 18hp from 1963. One other thing; the sparkplug is an NGK b9hs, and is not that a little bit warm?? (I am sorry if you dont understand me, i am 17 years old from norway!!!)<br />Thanks!!!!!!

 

[JB]

Re: johnson 20/18 help please!!!

Hello, Henning.<br /><br />Your English is excellent, better than some of us <br /><br />The powerhead from a '66 20hp FD-20 engine can be mounted on the same leg as the FD-18. Perhaps that has been done to your engine.<br /><br />The actual performance difference is negligible except at full speed.<br /><br />Good luck.

 

[henning_dt85]

Re: johnson 20/18 help please!!!

thank you. The powerhead is the original. The same modelnumber is also printed some place else on the engine.

 

[backdraft]

Re: johnson 20/18 help please!!!

Henning, NGK plugs get colder as the number goes up . A B6HS would be a hotter plug. A B5HS would be hotter still. There should be a number on a round plug on the block. If this number matches the one on the ID plate ,it's the original block. nevjb PS You spelling is better than three quarters of the forum members.

 

[rickdb1boat]

Re: johnson 20/18 help please!!!

Plug Info:<br /> <br />web page <br /><br />The recommended plug is:<br /><br /> B6S #3510 Gapped at .030