Outbord engine problem

[Fixit]

I have a 1972 Johnson Triumph 65 HP with a history of failed power packs. What would be the most probable cause of failure to this part?When engine fails to power up it usually causes the #1 and #2 cylender to not fire and # 3 will carry the load untill the power pack is replaced.I have just recently acquired this engine but am familiar with it's history of neglect( usualy sitting for long periods of time), but not with its maintnance.<br />fixit

 

[sirlespat]

Re: Outbord engine problem

Replace your sparkplugs, gap them correctly and test or even better replace your leads. The spark plug acts a voltage limiter on the output of the coil. If it is too hard for the spark to jump across the plug it finds somewhere else to go. If your motor has separate coils these could be puting the spark back to the power pack and damaging it. Use one of your old spark plugs to check that you get the same colour size spark from each coil in turn. If you have a weak spark on one (or three) then check it more closely.<br />never ever run your old motor with a plug pulled off.<br />Take it from a guy who got a project boat, have some fun with it as soon as you get it running and gradually build up trust in it.<br />Going fishing tomorrow!!!!<br />Good boating

 

[Fixit]

Re: Outbord engine problem

Thank you for the response. I didn't mention that the engine has CD plugs and they have been replaced as with the ign. wires. The engine is extreamly( in my openion) responsive with the start, about two turns and it's running, has a healthey spark and develops full power at about 4800 rpm,doesnt consume an abnormal amout of fuel,etc. it is just that it has had two power packs fail (reason unkown) in the last<br />several years. I have run all tests that the service manuel directs, with exception of the M-80 lamp test.( dont have one,havent located one) this is just a curiosity thing on my part--thanx to all <br />Fixit

 

[Dhadley]

Re: Outbord engine problem

Does your battery have wing nuts?

 

[ob]

Re: Outbord engine problem

Dhadley may be onto something.Don't know first hand about your application but seems I heard some of the older style powerpacks were of capacitance discharge design and that a battery of insufficient amps could lead to premature powerpack failure.I believe Joe Reeves is the expert here.

 

[Joe Reeves]

Re: Outbord engine problem

Fixit..... The following may be of some help. You can test the powerpack as follows:<br /><br />(Battery Capacitance Dischage Powerpack Test)<br /><br />Purchase a small 12v bulb at your local automotive parts store (the 12v bulb is to look like a flashlight bulb, not a headlight bulb). Solder two wires to that bulb, one to the side of the bulb (ground), and the other to the positive point. <br /><br />Remove the spark plugs. With the key in the on position, make sure that you have 12v going to the pack at the terminal block (purple wire). Now, connect the ground wire from the bulb to any powerhead ground. Connect the wire from the positive point of that bulb to the powerpack wire that is connected to the coil wire on the terminal board (blue wire). <br /><br />Crank the engine and observe that bulb closely (CLOSELY!). If that bulb glows even the slightest bit, the powerpack is okay. It may be a very dim glow... just so it glows! If it doesn't glow, the pack has failed. <br /><br />Keep in mind, that type powerpack (Battery Capacitance Discharge) demands a top notch battery of at least 70 amp hours. Any less will, in time, cause powerpack failure.<br /><br />(Poor connections anywhere, disconnecting the battery while running, using a faulty battery, would cause a powepack of that type to fail.)

 

[ob]

Re: Outbord engine problem

Amen

 

[Fixit]

Re: Outbord engine problem

Joe,<br /> thank you for the info -as with all problems with of this nature , the answer all ways seem to be right in front of a persons face, all I had to do was look. The past failure rate co-insides with the battery status during the previous owners possesion.IE his neglect of the craft and habit of letting the battery sit unattended untill he wished to use it. Now I should learn more about the cd system and take heed to NOT let the battery sit unattended over the months os un use. Thanks to all who responded you have been a great help<br />Fixit.

 

[petryshyn]

Re: Outbord engine problem

Hi Fixit<br /><br />All the above info is pertinent. But to put things in a nutshell, the common cause of failure is that the pack is getting too high a charging system voltage(above 15v).<br />>loose or corroded cables from battery to solenoid or battery to ground = allows charging voltage to climb<br />>sulphated battery = not enough load on system allows high charge voltage<br />>too small battery size = no enough load on system once fully charged (could be counteracted by keeping some accessory on)<br /><br />If it were mine, I'd add a voltmeter to the system. Don't connect it up in the conventional manner. Connect it directly between the solenoid positive terminal, and the ground connection of the pack. This will allow you to monitor system voltage right near the pack. If you have any detramental resistances, bad connections, sulphated or bad batteries, this voltage will read high (above 15v) warning you of impending failure.....<br />