Clicking Noise

[Bob Grieb]

I have the pistons and valves out of the Cub engine. When standing in front of the engine and turning it clockwise I am getting a clicking noise every 360 degrees. When I turn it counterclockwise I do not hear the clicking.

Is this normal!!!

Thanks

Bob

[johnbron]

If it has a Mag and its still on it then that is the clicking noise you are hearing. That is also normal and nothing to be concerned about. Thats only if the Mag is still attached.

[Bob Grieb]

Thanks Bronson

It is a mag system and the mag is still attached.. I plan on removing the mag after I install the pistons & valves. I am worried I may have difficulty with timing if I remove the mag assembly now. I can't install the lower radiator hose without removing the mag assembly.

Thanks for your help.

Bob

[Charles (49) Mo]

Yep, been there, done that...
You might consider this, when pistons and valves are installed, hand crank it over untill the front piston ( #1 cylinder) is fully upward as far as it will go. Look at the valves, you want them both completely closed, indicating the cylinder is ready to fire. If both valves are not closed, hand crank it again one more revolution till the piston comes up completely again with both valves closed. Check the timing mark on the front pully to be shure it is aligned with the pointer. Then take the Mag cap off the magneto and put a mark with something good on the inside of the case of the "EXACT" position of the bug (rotor) tip. Then you can remove the magneto assembly and you know where it has to be again to be in the correct spot. Wiggle the bug by hand and put maximum marks on the case if its a bit loose. Gears are spirial you you might be 1 tooth off when you reinstall it, but you know right away from the marks if its right. Assumption is that it was correctly timed before overhaul.
Anyone know if I missed anything or have something backward? (Memory not 100%)

[Bob Grieb]

Thanks Charles -

I'm waiting on rod bearings so I can begin the assembly process.

Bob

[John *.?-!.* cub owner]

Bob, if you are hearing click every 360 degrees you have a problem with mag. it should trip every 180 degrees.

[ldj1002]

Bob,
You should EITHER make sure the kill wire is attached and switch is off or pull the coil wire out of the distributor and ground it. It could ruin you mag by letting the spark jump or try to jump over 1/4" in or so.

[Bob Grieb]

Thanks for your input. I do get the click every 180 degrees - My mistake

I do not understand about damage to the Mag. I have all the wiring to the switches disconnected. The distributer cap is still on as are the plug wires. What do I need to do to avoid damage to the magneto??


Thank you guys

Bob

[Bigdog]

Bob - as ldj1002 stated - either ground the mag coil wire or make sure the kill terminal is grounded. The mag generates a high voltage energy that is looking for (chassis) ground. If the sparkplugs are in and connected to the cap you are OK since they are the normal path for the energy. If the plug wires are not connected to the plugs, the energy created by the mag will find a place to ground itself and that is usually through the internal components of the mag. This is not good. Some other mags have a built in spark gap to protect the internal components. The J4 mag has no provisions to deal with this energy except through it's normal path.

[Bob Grieb]

The head is off so the plugs are not providing a path. The switches are gone.

So do I ground the low voltage wire from the mag or the large dia spark plug wire going to the distrbutor?

I haven't spun the engine a lot so I hope I have not damaged the Magneto

Thanks for your help

Bob

[Bigdog]

The simplest thing to do is to ground the wire on the side of the distributor that runs to the kill switch. That will do the same thing as having the switch in the off position.

[Bob Grieb]

Thanks Big Dog -I'll tend to that this morning

Bob