1957 Sportwin Sparkplug comparison

[flexon_guy]

What difference would a champion J4C vs. J6C plug make in my 10 h.p. Sportwin? Could I use either one? Which one runs hotter?

 

[Chinewalker]

Re: 1957 Sportwin Sparkplug comparison

Hi FG,<br /> The J6C would run a little hotter and in my experience is a better plug for that motor. The J4C will run fine, but may be a little more prone to fouling at trolling speeds, particularly with the 24:1 oil ratio you should be running. I use J6Cs in all of my 1950s Johnrude twins and they burn perfectly, nice light chocolate color. The J4Cs I've used tend to carbon up a little more...<br />- Scott

 

[flexon_guy]

Re: 1957 Sportwin Sparkplug comparison

Scott<br /><br />Doesn't the 1957 run on a 50:1 oil ratio?<br /><br />Thanks for your help.<br /><br />Mike

 

[bubbakat]

Re: 1957 Sportwin Sparkplug comparison

no the 57 runs on 24:1 ratio

 

[Chinewalker]

Re: 1957 Sportwin Sparkplug comparison

Hi Flexon-Guy,<br /> Absolutely not. Your motor requires a 24:1 mixture, as much for the sealing and cushioning properties of the oil as for the lubrication. The oil acts as a cushion seal between crankcase chambers and aids in compression. Your motor has bronze bearings at several rotating journals and again the oil lubricates and cushions in these areas..<br />- Scott

 

[flexon_guy]

Re: 1957 Sportwin Sparkplug comparison

Scott<br /><br />Your right. I am overhauling this engine and it appears as though the previous owners have run this engine on 50:1 because it says oil mixture 1 pint to six gallons on the presure tank. He also said that he thought the engine was from the 60's. If this is the case what do you think I should check in the engine for excess wear from poor lubercation? <br /><br />Maybe this is why he was running J4C plugs also.<br /><br />Right now I am looking for the top seal for replacement and cannot find one (maybe there is not one). There was oil present under the magneto and Seloc said to go ahead and replace the upper crankshaft seal in this case.<br /><br />Anyway what do you think I should check for excessive wear?<br /><br />Thanks<br /><br />Mike

 

[Paul Moir]

Re: 1957 Sportwin Sparkplug comparison

Have a look at this web page:<br /> '58 Sportwin webpage. <br /><br />Does the seal arangement look right? I'm not sure if there's a change between '57 and '58, but if there's a roller bearing at the top of the crankshaft, there's got to be a seal. I don't think the 'slinger' arrangement (like on p 3-45 of your Seloc on the 5.5hp block) would work without a plain bearing.

 

[flexon_guy]

Re: 1957 Sportwin Sparkplug comparison

Thanks Paul<br /><br />I found two little holes in this seal across from each other up against the crankshaft. I used two dental picks to lift and turn at the same time this seal slipped out real nice. This I think is a beter technique that what Seloc recommended. <br /><br />Does any body know where I can find this upper seal? Its not available from Iboats.<br />Mike

 

[Chinewalker]

Re: 1957 Sportwin Sparkplug comparison

Hi Flexon-Guy,<br /> Take your existing seal with you to a bearing shop (.ie Kaman, etc.). They can either match it up with the CR-number, or mic it and match it up that way. <br />- Scott