another oil/gas ratio question

[chosen]

I've got a Sears 4.5 Model #21759162, Serial # 204089. I think it is an "Eska/Tecumseh" from the early 70s and I know they changed the ratio right about then. Would this be a 50:1 or a 24:1? Also, any recommendation on which plug to use and what gap? It runs good...I don't want to hurt it with the wrong ratio. Thanks Also, how hard is it to replace the impeller and are new impellers available? Thanks again.

 

[rickdb1boat]

Re: another oil/gas ratio question

Hey Chosen,<br /><br />Can you double check that serial number, as the nearest I can find is 21759(4)62 which is a 1972 model. Oil mix is 24:1, Spark Plug is Champion J-13-Y @ .030. Check this page out and see what you think...<br /><br /> web page Parts available on this site, also...

 

[JB]

Re: another oil/gas ratio question

Don't use outboard oil. It is for water cooled engines.<br /><br />Use chainsaw or weedwhacker oil.

 

[chosen]

Re: another oil/gas ratio question

Originally posted by JB:<br /> Don't use outboard oil. It is for water cooled engines.<br /><br />Use chainsaw or weedwhacker oil.

It is water cooled. Do you agree on the 24:1 ratio?

 

[chosen]

Re: another oil/gas ratio question

Originally posted by rickdb1boat:<br /> Hey Chosen,<br /><br />Can you double check that serial number, as the nearest I can find is 21759(4)62 which is a 1972 model. Oil mix is 24:1, Spark Plug is Champion J-13-Y @ .030. Check this page out and see what you think...<br /><br /> web page Parts available on this site, also...

 

[chosen]

Re: another oil/gas ratio question

Thanks! That was a great page. Interesting how you get so many different answers to the ratio question, but this page seems authoritative. I haven't been able to find a J13Y either. I'll check with Champion and see if they still make it. I got from "O'Reilly" what they say is the equivalent. You were right on the model number, too. It is 21759462. The plate is a little scraped and I took the "4" for a "1". Thanks Rick. BTW, I know my post says "cadet", but it took 26 years in the Coast Guard to make Captain, so I'll take that instead of "cadet!"

 

[rickdb1boat]

Re: another oil/gas ratio question

So you know, Champion recommends a RJ14YC Gapped at .035 for your motor...<br /><br /><br /> web page

 

[chosen]

Re: another oil/gas ratio question

Originally posted by rickdb1boat:<br /> So you know, Champion recommends a RJ14YC Gapped at .035 for your motor...<br /><br /><br /> web page

 

[chosen]

Re: another oil/gas ratio question

Thanks again Rick. I had checked on the Champion Web site and found the same thing. I'll get a couple of them. Should I expect them to foul quickly at 24:1?