'73 115 Johnson Fuel problem- Have to prime motor into intake before starting

[ndanieltx]

Donkeypunch,<br /><br />I combined your two posts. They wewre the same question.<br /><br />1973 Johnson 115 v4. Curious about 50-75% of time I start it I have to first pop the cowl on it and pour a little gas down the intake to get her to run. Especially if she has sat for awhile. If I shut her down and then crank it back up immidiately it runs ok. If I shut her down for more than about 10-20 mins or longer it seems I have to prime it every time. Any ideas? Fuel Filter has been replaced fairly recently. <br /><br />Thanks!

 

[Joe Reeves]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Does the choke operate?

 

[ndanieltx]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Checked the choke before. It is working (switch on controls moving the lever).<br /><br />I can pump the bulb till the cows come home. It gets firm, but then it still wont run or stay running till I pour some fuel into the air intake and start it then pull the warm up handle.

 

[moderator1]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

I have a 25 ft Crest Pontoon with a 1973 Johnson 115. Sometimes she fires right up no problem. Other times she wont fire at all (even after spraying starting fluid in the intake) . To get it to start we have to either connect a second batter or jump off. Or we use the DC Output on a small Honda Generator to top off the charge on the starting battery. We replaced the battery and starter(which seemed a bit wore out). This helped for awhile but now we are having the problem agian. It seems to need a fully charged battery at 100% now to start. I KNOW it will always eventually start if we can just get a really hot battery . <br /><br />Does this sound like a Stator Problem? Maybe cranking speed = fire. Wore stator less fire?<br /><br />Rectifier?<br /><br />A few other things I should mention. This boat has been really customized with a lot of running lights, nice stereo. All those goodies . I am really thinking this old outboard doesnt have the charging capacity to run more than running lights and a spot light. Back in 1973 I doubt many people ran as much electrical as they do. So when we go out we drain the battery a lot and if the engine isnt running at a high enough RPM then we are draining more than we are Charging.Anyone know the Charging Output of the 73 Johnson 115? <br /><br />Thanks!<br /><br />--------------------<br />ZanTaR<br />1977 Crest 25 Ft Pontoon with-<br />1973 Johnson 115 v4<br />1985 Chris Craft Scorpion 5.0 v8 GM<br />1996 Sea Doo GTX 110hp 751cc<br /><br />--------------------------------------------------------------------------------<br />Posts: 3 | From: Wylie Texas | Registered: Aug 2003 | IP: Logged <br /> <br />ledgefinder <br />Captain <br />Member # 9054 <br /><br /> posted August 11, 2003 12:49 PM <br />--------------------------------------------------------------------------------<br />Check the solenoid. Internal resistance in the solenoid can behave just like a low battery or dying starter motor. You have to make the connections really solid to get a good test. <br />--------------------------------------------------------------------------------<br />Posts: 329 | From: mass | Registered: May 2002 | IP: Logged <br /> <br />Donkey Punch <br />First Mate <br />Member # 30609 <br /><br /> posted August 12, 2003 07:34 PM <br />--------------------------------------------------------------------------------<br />Thanks for the idea and help!<br />Replaced the Solenoid (because its very cheap). It seems to have helped a little (seems a little stronger longer) but alas. I tested it by running the electrical a bit on the boat. Then trying to start it.. No dice Right back to the same symptom. Have to either jump it with the other battery or charge with the D/C Generator. More and more I am thinking the stator is wore and weak and just doesnt fire when cranking speed isnt just really fast. Any other ideas are appreciated. <br /><br />Note: This is a seperate issue than my fueld problem. But for a note when it doesnt fire not even starting fluid will kick off a pop or fire until the batts charge enough to crank over the motor fast enough.<br /><br />--------------------<br />ZanTaR<br />1977 Crest 25 Ft Pontoon with-<br />1973 Johnson 115 v4<br />1985 Chris Craft Scorpion 5.0 v8 GM<br />1996 Sea Doo GTX 110hp 751cc<br /><br />--------------------------------------------------------------------------------<br />Posts: 3 | From: Wylie Texas | Registered: Aug 2003 | IP: Logged

 

[sparkroost]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Be sure that when you hit the choke, the flappers on the carbs are closing COMPLETLY. This is very important. That should solve your cold start problem of having to add fuel to make it start.

 

[ndanieltx]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Thanks Sparkroost. I am going to check that today and see whats happening. I should also say that I have to prime the motor even if its been run awhile so I am not sure this is a cold starting only issue.

 

[ledgefinder]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Ditto what sparkroost said. The flaps on those motors have to slam shut 100%, 99.94% won't do it. It's easy to adjust the action by loosening the solenoid strap bolt, then pulling solenoid down - or my messing with the spring. <br /><br />There should be a manual override on the choke (port side of the motor). Snap that to "on", from "automatic", & if she starts good cold that way then you know what the problem is.

 

[harley909]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

I have a 70hp Johnson that has a sticky needle valve/seat in one carb. It is hit and miss on starting but once it does it works fine for the rest of the day. It seems to build up enough pressure after sitting to make it stick. It usually starts and runs out of gas in a few seconds and won't start again.<br />Sometimes a shot of gas in the carbs makes it run and it is OK. <br />Kind of sounds the same as your problem. I only figured mine out after I replaced the fuel lines to the carbs with clear fuel hose. I could then see the exact problem and it made sense.<br />Might be worth a look on yours.

 

[ndanieltx]

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Re: '73 115 Johnson Fuel problem- Have to prime motor into intake before startin

Looks like the choke is closing completly. It did its usual not starting game the other day . Crank crank crank nothing. Squirted some starting fluid in her.. NOTHING no pop or spark. Took the plug wires of and checked for fire. Nothing! Pulled the plugs out of the motor.. Cranked it AHHAH!!! SPARK!! Charged the batt real good put plugs back in BAM she fired right up.<br /><br />This has to be the stator worn yes?