Johnson 25HP no start

[jtexfisher]

'Mornin...<br /><br />Been trying to get a 25hp to start.<br />To date:<br /><br />1.) Checked spark. Good to both cyls.<br />2.) Cleanded carb. All passages look good, float level ok by the Clymer book.<br />3.) Fresh fuel, good 50:1 mix.<br />4.) Choke being run manually. I've tried with just about every combination of choke I can think of.<br />5.) Timing? Haven't looked. Motor was running at storage 1yr? ago.<br />6.) Compression....should it check like 4 cycle motor? Just look for even pressure in both?<br /><br />Stumped..<br />Jtex

 

[DHPMARINE]

Re: Johnson 25HP no start

Compression check like any motor,look for close readings.If under 70psi,running may be doubtful.<br /><br />Does your choke close 100% ? That is mandatory.<br />Also,spark test.Did spark jump at least 3/16 inch ?<br /><br />What year is this?<br /><br />DHP<br /><br />good luck ! !

 

[OBJ]

Re: Johnson 25HP no start

After checking compression and checking that the choke plates are closing 100%, you might try squirting some premix directly into the throats and see if that kicks her over.<br /><br />As DHP posted, would be nice to know what year this is. A model number would be even better.

 

[jtexfisher]

Re: Johnson 25HP no start

25E72R ... '72 model?

 

[jtexfisher]

Re: Johnson 25HP no start

No change with the fuel spray. Still looking through the shed for the comp. gauge!<br />jt

 

[G DANE]

Re: Johnson 25HP no start

Did you ( or someone else earlier )eventually swap plug wires or charge wires to coils ?? When did this motor run fine last time ??

 

[OBJ]

Re: Johnson 25HP no start

GD...his original post said it ran at storage 1yr. ago. Being an electric start, might be worth a try to disconnect the wire harness at the engine and try to pull start it. That would at least eliminate the key switch.