How adjust Onan 6.5 genset idle/running ?

Doesn't the link I put in post #12 refer to the MCCK H model? That ladder diagram should be the one for your generator. Let me know if if isn't and I will try to track down the differences.

Hi,

I would suggest that just for a test that by passing it will show if it is at fault, there will not be a catastrophic meltdown of your points in a short time if at all. If there would be then more mfrs would use them std, I personally have not seen one used this way and I did my time as a mechanic albeit Diesel based we still say plenty of older Gas engine farm machines.

I'll try one last time.

What's the model number?

i believe the model # is mcck j. it is in a tight housing so obtaining the whole number is next to impossible unless i take the housing walls apart. do you know about the 2 bosch relays in the wiring panel. one is located below the ignition switch, the other is near the top of the panel.

The file is too big to attach. Pls send your email address via PM and I will send the control system wiring diagram for the MCCK/J.

HI AND THANKS. MY ADDRESS IS STEVE.NCIS@NECLAIMS.COM
DO YOU HAVE ANY LITERATURE DESCRIBING THE RELAYS IN QUESTION. THANKS AGAIN FOR THE HELP.

The manual and a schematic should be in your inbox as I type this. Good luck and let us know how you do.

Thanks I Got It. I Sent A Couple Of Photos Of The Old Chris.

If you have a non-magneto points ignition on a gasoline (petrol) engine, you have a ballast resistor. If you do not see one externally inline to the coil, it is integral in the coil. If there is none, the points will fail, not immediately, but within 50 hrs of running time. It is perfectly safe to jump across it with a wire for a test.

I'll try that next. i didn't want to burn out the ballast resistor. shouldn't i detach at least one wire. i am starting to concentrate on the run relay which i think is below the the start switch in the electric panel mounted to the genset. marmot was kind enough to forward me a manual.thank you for the suggestions. now i just have to find the time. unfortunately i just received word that the boat is coming out of the water on friday. sad time in the cold climates. best to you.

Not necessarily. This particular J model does happen to have one, other versions of the same engine which use a different control module and coil don't use a ballast resistor. This is illustrated very well when you look at the link I gave to the H model which doesn't use a resistor and the J model schematic I sent today. If you don't know, don't make absolute statements about the components that are used. They vary considerably between models and serial numbers within a model number. A prudent troubleshooter doesn't make such firm assumptions.

A balllast resistor is used when a 6 volt coil is installed on a 12 volt system. Full voltage is available to supply a hot spark for cranking but for running, the resistor limits the current through the run circuit. If a 12v coil was installed as a replacement the resistor would not be needed and may have been removed. Two separate circuits supply power to the coil. One for starting, one for running.

In addition, the safety switches for oil pressure, high exhaust temp, and high coolant temp are in series with the run circuit and may as likely be the source of the problem. A good troubleshooter does not fixate on a single item. Like I said, eliminate the items that will not cause the problem and go from there. There is no need to start jumping things out when the simple and safe application of a multimeter to the right componenets will provide the answer. Use brain before tools.

Hi,

I will also have to disagree with the opening lines of your statement above.

A faulty Condenser is the most likely cause of points burn out in a short time.

Here is a straight forward description of what each component does in a Points based Ignition System.

Ignition Coil: This is the part that makes high voltage, up to 40,000 volts, for the spark plugs from the low voltage that is supplied to it by the battery. The reason an ignition coil works lies in the physical properties of electrical current. When a current flows through a conductor it generates a magnetic field around the conductor. Conversely, when a conductor is moved through a magnetic field, a voltage will be induced in the conductor. The coil takes advantage of these principles of inductance by winding one coil over the top of another around an iron core. The changing voltage in the primary winding serves as the 'movement' needed to induce a voltage in the secondary winding. The voltage in either winding is proportional to the number of coils in the inductor; if there are more turns in the secondary, its induced voltage will be higher than the voltage in the primary.

When the points close, current through the coil primary increases from zero to maximum in an exponential manner, rapidly at first, then slowing as the current reaches it's maximum value. At low engine speeds, the points are closed long enough to allow the current to reach a higher current level. At higher speeds, the points open before the current has time to reach this maximum level. In fact, at very high speeds, the current may not reach a level high enough to provide sufficient spark, and the engine will begin to miss. This current through the coil builds a magnetic field around the coil. When the points open, the current through the coil is disrupted, and the field collapses. The collapsing field tries to maintain the current through the coil. Without the Condenser, the voltage will rise to a very high value at the points, and arcing will occur.

Points: Ignition points are a set of electrical contacts that switch the coil on and off at the proper time. The points are opened and closed by the mechanical action of the distributor shaft lobes pushing on them. The points have a tough job, switching up to eight amps of current many times per second at highway speed. Indeed, as engine speed increases the efficiency of your ignition system decreases, thanks to heating problems and fundamental electrical laws. This declining efficiency has a serious effect on your spark voltage and results in poor high-speed performance, incomplete combustion and other drivability problems.

Condenser: Those same principles of inductance create a kind of paradox, because when the points open and the magnetic field collapses it also induces a current in the primary as well. It's not very much because there are only a few windings in the primary, but it's enough to jump a small air-gap, such as the one between the just-opening points in the distributor. That tiny spark is enough to erode metal away from the points and you'll 'burn' the points. It prevents the points from arcing and prevents coil insulation breakdown by limiting the rate of voltage rise at the points.

Ignition Coil: This is the part that makes high voltage, up to 40,000 volts, for the spark plugs from the low voltage that is supplied to it by the battery. The reason an ignition coil works lies in the physical properties of electrical current. When a current flows through a conductor it generates a magnetic field around the conductor. Conversely, when a conductor is moved through a magnetic field, a voltage will be induced in the conductor. The coil takes advantage of these principles of inductance by winding one coil over the top of another around an iron core. The changing voltage in the primary winding serves as the 'movement' needed to induce a voltage in the secondary winding. The voltage in either winding is proportional to the number of coils in the inductor; if there are more turns in the secondary, its induced voltage will be higher than the voltage in the primary.

When the points close, current through the coil primary increases from zero to maximum in an exponential manner, rapidly at first, then slowing as the current reaches it's maximum value. At low engine speeds, the points are closed long enough to allow the current to reach a higher current level. At higher speeds, the points open before the current has time to reach this maximum level. In fact, at very high speeds, the current may not reach a level high enough to provide sufficient spark, and the engine will begin to miss. This current through the coil builds a magnetic field around the coil. When the points open, the current through the coil is disrupted, and the field collapses. The collapsing field tries to maintain the current through the coil. Without the Condenser, the voltage will rise to a very high value at the points, and arcing will occur.

Points: Ignition points are a set of electrical contacts that switch the coil on and off at the proper time. The points are opened and closed by the mechanical action of the distributor shaft lobes pushing on them. The points have a tough job, switching up to eight amps of current many times per second at highway speed. Indeed, as engine speed increases the efficiency of your ignition system decreases, thanks to heating problems and fundamental electrical laws. This declining efficiency has a serious effect on your spark voltage and results in poor high-speed performance, incomplete combustion and other drivability problems.

Condenser: Those same principles of inductance create a kind of paradox, because when the points open and the magnetic field collapses it also induces a current in the primary as well. It's not very much because there are only a few windings in the primary, but it's enough to jump a small air-gap, such as the one between the just-opening points in the distributor. That tiny spark is enough to erode metal away from the points and you'll 'burn' the points. It prevents the points from arcing and prevents coil insulation breakdown by limiting the rate of voltage rise at the points.

Ballast Resistor: This is an electrical resistor that is switched in and out of the supply voltage to the ignition coil. The ballast resistor lowers voltage after the engine is started to reduce wear on ignition components. It also makes the engine much easier to start by effectively doubling the voltage provided to the ignition coil when the engine is being cranked. Not all manufacturers used a ballast resistor in their ignition systems So you should check to see if yours does.