Johnson 5 horse ignition

[DUNE]

I have a 1951 TN 27 I can't get to run. In checking the spark plug wires with a multi meter it looks like the bottom plug wire is connected to ground and the top one is not. Is this right? Also, does anyone know where to buy a float (a NAPA number?) for the carburetor or maybe a kit?

 

[JB]

Re: Johnson 5 horse ignition

Hi, Dune.<br /><br />Are you getting spark on either one?<br /><br />The TN has "a" magneto that is really two independent magnetos. They share the flywheel and points cam. There may also be a kill circuit that has been added aftermarket.<br /><br />An open reading to ground might indicate an open coil secondary. Does the reading stay the same regardless of the flywheel position? But that would only affect spark for one cylinder. It should start and run on the other.<br /><br />I suggest that you do the sequence in "Outboard wont start" in the Engine FAQs and let us know what you find.<br /><br />Good luck.

 

[Chinewalker]

Re: Johnson 5 horse ignition

Hi Dune,<br /> The NAPA number for a float that will work (with minor mods) is 18-7208. It's actually for older Mercs, but it's close enough to the Johnson TD/TN series float that it works just fine...<br />- Scott

 

[DUNE]

Re: Johnson 5 horse ignition

Thanks,i didn't have much faith in the cork float even though I resealed it.<br /><br />-Dylan

 

[DUNE]

Re: Johnson 5 horse ignition

Thanks, I am new to the board. I was planning on getting a new float, but haven't actually done it yet. Being that the engine started and ran so well I was questioning the need for a new float. Obviously, I would rather not take the carb apart again but it looks like I need to to get the engine running properly. I appreciate the advice.

 

[tin knocker]

Re: Johnson 5 horse ignition

I have the carb apart on my TN 26 and would like to replace the cork float. If I get the NAPA float just how much modification is required and will I have difficulty adjusting the float height? I don't really look forward to removing the carb a second or third time to get it correct. I am not all thumbs, but when working in confined areas I seem to have more than my share.

 

[Chinewalker]

Re: Johnson 5 horse ignition

Hi TK,<br /> The primary mod is to drill out the center so that it'll fit over the float needle shaft. Align the BOTTOM of the float with the current float's position to assure proper float level... there should be a slight groove in the shaft to mark it...<br />- Scott

 

[DUNE]

Re: Johnson 5 horse ignition

On my TN 27 I have a groove in the float shaft that sits even with the top of the float.The shaft has a notch for a clip and a screw holding the float in place. Is the replacement Merc. float the at the right level if the clip is placed in the groove on the float shaft? This would be with the top of the float in the same place as the old one. Is the Merc float exactly the same size other than the hole in the center?

 

[tin knocker]

Re: Johnson 5 horse ignition

Thanks Scott. I have ordered the float and it will be here Wednesday. I really appreciate your help. Now if I can remember where all those small parts go I will be in business.

 

[WillyBWright]

Re: Johnson 5 horse ignition

Float??? I went to St. Vinnie's and got a bottle with a cork and trimmed it down and drilled the center hole, covered it with shellac. Fifty cents! Gave the bottle to my daughter. Got it back together yesterday, firing it up this morning. Gonna Camo it, though. Somebody already "painted" it. <br /><br />Did you get it back together? Parts manuals help. Check on eBay. Sometimes manuals are available. Use keywords "classic johnson parts catalog" or "manual". TNs and TDs use the same carb.