78 Johnson 25 wont start without ether

[buffbenj]

Bought a model 28EL78C 25 hp Johnson on a small bass boat. Was told it only needed a power pack. Ordered for $55 and installed. I assume the small single black wire on the power pack is a ground, so I attached it to the block. Old magneto had already been removed, and new one does match up. Cleaned fuel filter. Fuel pump works. It will start and run for 1-2 seconds with starting fluid, choke or no choke. Sure seems like it is not getting gas. Primer bulb is firm with pumping and feels normal. Seems the next step is to pull the carb and inspect and clean. Any other advice? I also have no idea what the factory setting for the mixture screw should be. Right now it is about 3 revolutions out from fully tightened.

 

[boobie]

Re: 78 Johnson 25 wont start without ether

Clean the carb and go from there.

 

[nwcove]

Re: 78 Johnson 25 wont start without ether

compression #'s ?

 

[bonzoscott]

Re: 78 Johnson 25 wont start without ether

Don't use any kind of starting fluid. Use your premix fuel/oil in a squirt bottle. You're taking hours maybe years off the life of the motor with starting fluids. Fuel eats up most plastics but I have had good luck with Armor-All bottles. If not, just rinse it afterwords.

 

[geoffwga1]

Re: 78 Johnson 25 wont start without ether

Bought a model 28EL78C 25 hp Johnson on a small bass boat. Was told it only needed a power pack. Ordered for $55 and installed. I assume the small single black wire on the power pack is a ground, so I attached it to the block. Old magneto had already been removed, and new one does match up. Cleaned fuel filter. Fuel pump works. It will start and run for 1-2 seconds with starting fluid, choke or no choke. Sure seems like it is not getting gas. Primer bulb is firm with pumping and feels normal. Seems the next step is to pull the carb and inspect and clean. Any other advice? I also have no idea what the factory setting for the mixture screw should be. Right now it is about 3 revolutions out from fully tightened.

If you keep using starting fluid in it you won't have it long.Lubrication for 2 strokes is in the fuel,no fuel=no lubrication.Put some mixed fuel in a squirt bottle and use that,then strip ,clean and rebuild the carb.

 

[buffbenj]

Re: 78 Johnson 25 wont start without ether

Ok will pull carb today. Thanks

 

[milliesdad]

Re: 78 Johnson 25 wont start without ether

Check the compression first. If it's got low compression, throwing parts and money at it won't fix it.

Then test the spark with a spark tester.

 

[buffbenj]

Re: 78 Johnson 25 wont start without ether

Starter was a bear to remove to get carb off. Forum helped alot. Carb needle valve was stuck in shut position, so gas wasnt getting thru. Plugs were gapped at 050, corrected to 030. Runs well, but there is some jimmyrigged wiring with 2 on/off switches on the motor. Previous owner installed them when key would not shut engine off. Now first switch acts as on/off and low idle, other switch allows motor to go to wot, but idles way too high with this one on. All key does is start it. It works as is, but I'll post pics of wiring to try to figure it out. Top end about 20 knots, so compression must be fine. I must admit I'd like to avoid buying a new/used throttle control. After all, paid $300 for boat, motor, trailer, and trolling motor. All work! Once again, thanks for your help.

 

[boobie]

Re: 78 Johnson 25 wont start without ether

Get rid of those switches and do the wiring up correctly. All it may need is a new key switch.