4 Cylinder Gas Engine No Spark- Help, Please

[ducksjunk]

If the points are burned, then it is usually caused by a bad condenser. Always replace then as a set.
Richard.

 

[Keoke]

Hi Ducks Junk, hey, I love the handle.
Defective or mismatched condensers (capacitors) will cause point pitting instead of the point burning that comes excessive current flow though contacts and movable arm.
On condensers there is a simple rule called the "Minus-Minus rule". Rule says that, minus material (hole) on the minus contact (usually gnd point) indicates a minus (under capacity) condenser. The reverse would indicate an over capacity condenser. A properly matched condenser would prevent metal (tungsten) transfer from one contact to the other.
Condenser capacity is measured in farads but this requires a meter that is hard to find. Your best bet here is when you have the right condenser (no metal transfer between contacts) is to not change that condenser when changing points. Condensers do not wear out so there is no reason to get rid of a good one unless you have too.
When looking for a good condenser check out the seal setup where the wire goes into the body. What you are looking for here is a tight seal to prevent moisture from getting in between the condenser plates. This is especially true in marine applications. Where the seal looks tenuous put a band of RTV sealer around wire.

cheers,

 

[MossRoad]

Well, opened it up this morning, broke off the rotor(broke, as in cracked in three pieces) removed the plastic plate under it and found lots of rust. The points were stuck wide open, even though the cam was nowhere near the little tab that rubs the cam. Sooo, I cleaned everything out and figure it is time to replace the points and condenser, and rotor, of course. May even get a cap and plug wires, too. /forums/images/graemlins/wink.gif

 

[hobbyfarm]

</font><font color="blue" class="small">( Well, opened it up this morning, broke off the rotor(broke, as in cracked in three pieces) removed the plastic plate under it and found lots of rust. The points were stuck wide open, )</font>

MossRoad,
By any chance does this thing live out in the weather? Or does it not get used much? Problems like this always seem to be the points. Thank goodness for electronic ignition! /forums/images/graemlins/smile.gif

 

[_RaT_]

<font color="blue"> Thank goodness for electronic ignition </font>

You bet. If it wasn't for that, my Kohler would have had the flywheel pulled many times getting the points replaced. /forums/images/graemlins/wink.gif

 

[MossRoad]

<font color="blue"> By any chance does this thing live out in the weather? Or does it not get used much? </font>

Yes and yes. It lived most of its life outdoors and has been sitting idle in the garage for a few years.

TSC didn't have the correct rotor, points and condenser, so I have to travel to a small town about 20 miles away to get one from an AG dealer. That's one of the downsides to living near a large urban area... no more agricultural industry = no more tractor parts. /forums/images/graemlins/frown.gif

I appreciate all the help so far and will update this forum when I get the parts... could be a week or so before I have time to make the drive.

 

[slowrev]

My Kohler has external points.

 

[Jagmandave]

Sounds like you found the culprit, don't forget to lube the cam lobes with a proper electrical grease, and put a little dab behind the contact block too, so as it wears it'll "uncover" new grease. Set the gap, and then with the points closed run a tab of dry clean cardboard thru them to clean off any residual oil on the contacts. You probably should pull the distributor and make sure the advance mechanisms are working too, if the points were this rusted up, chances are they aren't moving either. Once you get it all back together, it should fire right up!

 

[MossRoad]

Pulled the plate that the points and condenser are mounted on. Had a heck of a time removing the points. They were frozen to the post big time. I had to remove the points mechanism piece by piece until all the was left was a little metal tube stuck to the post. I heated it with a small torch and was able to remove it.

Got new points and condenser from NAPA today. The ones from TSC were not correct.

The advance weights are a mess. Lots of rust. I will be cleaning those up later this week before replacing the points and condenser.

 

[Soundguy]

Penetrating oil on that advance mechanisim may help it free up.

Soundguy