1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont restart

I bought this motor/boat back in the spring.When I first took it out, it ran really bad and I took it to a marine mechanic who rebuilt the carburator andput a new coil,plugs and wires,and points and condencer on it.The primer bulb was leaking on it so I whent to wallmart and bought a new line and spliced in an inline fuel filter like was on it.My problem is that the motor will start cold, but is sort of rough warming up,but not real bad.After tht,it runs great at full throttle,but not as good at real low speed.After I shut it off,(after about an hour or so) it wont start back up for 45-60 minutes.The primer bulb is holding pressureat start,after that , its not.The mechanic thought it could be the line or maybe the fuel pump,but then again,he was 95% sure it was the coil the last time.JB or anyone have any good ideas? been wanting to get in some lake time since springand fall is around the corner!Any answers or comments on this make and model are appeciated.Thanks Bluebelin

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

If it helps,the model number is V4 SL 125

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Checking back in from last night , anybody help me with this?

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

SOS!

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

I sympathize with your impatience, Bluebelin, but getting pushy isn't going to give me any ideas I didn't already have. If I have an idea, you can be sure I will post it. Meanwhile maybe someone who knows more about your symptoms than I do will have an inspiration.<br /><br />Good luck<br /><br />JB

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

I am not an expert, but if the engine was serviced and it starts after cooling down, <br />I think it is gas flow...... Do you have a<br />tank with a vent? Is the vent open and unobstructed? Just a guess here Good luck

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

I've seen condensors do this. Was the condensor he use a NOS(new old stock)or did he get a fresh one from NAPA/Serria. Some of the old ones laying around in stock can pick up mositure. Either way the condensor is only a few bucks, I'd try another one.<br /><br /> When the engine go's into this non starting mode pull the plugs and see if they have fuel on them. If their soaked then you may be having a problem with auto choke trying to choke her when she doesn't need it. After that lay one or two plugs on the block and crank her over to see if you have spark. My money's on a bad condensor because those down draft carbs on her do nothing but dump fuel into those engines.

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Hmmm. WA3's idea is good, and it got me thinking about "cool down". After you have checked out fuel tank venting and other fuel flow related possibilities as WA3 suggests, if you haven't found the cause of your problems let's see what heat might be doing to prevent a start-up.<br /><br />I don't see anything about water tell-tale or impeller replacement in the list of things that have been done. How is the tell-tale? Is it strong and warm, but not steamy?<br />If there is any doubt, and there usually is when you can't say when it was last replaced, replace the impeller.<br /><br />One of the very good reasons that wrenches are fond of saying "If it aint broke, don't fix it" is that, with electrical parts in particular, new ones are more likely to fail than old ones. The electrical part that may be suspect here is the new coil.<br /><br />The temperature of the engine will normally rise for a few minutes after shut-down as heat makes its way from the combustion chambers to the air. Do you idle the engine cool before you shut it off or do you pull it in from full chat and shut her off right now? Could the coil be failing when hot and working fine when cool? Stranger things happen every day.<br /><br />Well, how do we find out if any of these things are happening? <br /><br />Warm her up real good. Shut her down and check for fire in the plugs. Each wire should provide at least 1/2" of arc to the block.<br /><br />Got spark? Get a can of WD40 and spray it into the air box or, better yet, the carb throats while turning it over. If that doesn't make her start there is something I don't understand (yet) going on. If she does start, but dies as soon as she has burned up the WD40, you have heat-related fuel starvation. If you have followed suggestions in the order given; no interference with fuel flow, water pump pumping, got spark and runs if you substitute WD40 for fuel, all I can think of is fuel pump failure after warm up. Try rebuilding the fuel pump.<br /><br />Note that I haven't suggested hiring a tech to do any of this stuff. YOU do it. Nothing I have suggested requires any complex equipment or special training. . . it is all stuff a boater should be able to do. There are lots of people here willing to coach you if you need it.<br /><br />The best wrenches don't ask you to pay for fixes that don't fix, but if you hire them to fix it and the fix fixes be prepared to pay what it is worth. I want you to do it because if the fix works it is our fix, not his. <br /><br />Red sky at night. . . . <br />JB

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Hey again. Don't get the impression that I ignored Dunk's input. Neither of us saw the other's ideas before they were posted. It's all good stuff.<br /><br />Red sky. . . .<br />JB

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

Re: 1960 Johnson 75hp v-4 outboard-runs for awhile,then after shutdown,wont rest

J.B.'s Idea is right on the Money! Make sure your water flow is good. A hot engine will shut down on it's own , and you can't tell if it's fuel or spark! Make sure the coil is "marine rated" , not a subsitituted automotive part. Also, check the system that advances spark. I don't know your engine but if the spark advance sticks while you are at high speed, the engine will not idle when you slow down, and it will not start until the advance goes back to starting position..... (usually happens after moving the throttle up and down a few times) Good Luck Dan