a stupid young buck question for the ol' timers

[ckelp]

well me being 28 i have never owned anything with points ignition till i started getting into the old saws,
with that being said i have a L65 at idle it runs perfect but once i open it up it start hitten' and missen' i have tried adjusting the high side even pulling the choke out and slowly pushing it back in at WOT with no difference it the way it runs.. it has left me stumped

this is what i have done so far replaced the coil and while diagnosing that i adjusted the points to .020" then got it to run adjusted the idle and now here i am

 

[rupedoggy]

Adjusting the points is good but on the L65 it is .012-.016. Also it is very important to file or sand the point contact area clean. Keep the contact points flat so there is maximum area for Make/Break. Try and see if this helps. When a point ignition works it is a surprisingly good system.

 

[Cantdog]

Adjusting the points is good but on the L65 it is .012-.016. Also it is very important to file or sand the point contact area clean. Keep the contact points flat so there is maximum area for Make/Break. Try and see if this helps. When a point ignition works it is a surprisingly good system.

Yep what he said...I usually set the points at .015" as the leg that rides on the cam follower wears they always work together. If you have then filed and matched and set properly and it still won't spool up it's more than likely the condenser.

 

[galde]

Whenever I encounter a saw with no spark, I much prefer it to be a points-n-condenser rather than an electronic ignition saw. In the case of the former, in nearly every instance spark can be restored by cleaning and re-gapping the points, whereas the electronic version nearly always means a new (expensive!!!!) ignition module.

 

[Frank Boyer]

Remember to lube the rubbing block/dist lobe with a slight amount of cam lube.

 

[DavdH]

condenser

 

[saxman]

I agree, condenser!!!!

 

[tdi-rick]

condenser

Bingo !

 

[madhatte]

I was taught early on to never file points, as the platinum coating is very thin and the iron underneath it corrodes VERY quickly. Instead, I clean points with a piece of paper card stock pressed between the contacts. Three or four passes is usually enough to restore bright, shiny platinum without nicking it at all.

The fact that your saw idles fine but misses at WOT definitely suggests a bad condenser. A condenser is just an electrolytic capacitor. It's job is to slow down the time it takes to discharge the spark as the field collapses once the magnet passes the coil, which is more critical at higher RPM's than lower ones. Electrolytes break down over time. What's happening is that the spark is getting to the plug well before the fuel does, and you're getting alternate misses and detonations on subsequent rotations of the crank. Replace the condenser and see if that doesn't clean things up. I'm betting that it will.

 

[ckelp]

if i remember the condenser is reading 25mUF i have a capacitor tester and thats normal for a condenser

 

[madhatte]

Sure, but you're reading that capacitance at 0 RPM. It's much harder to test it at 6 grand!

 

[Cantdog]

I was taught early on to never file points, as the platinum coating is very thin and the iron underneath it corrodes VERY quickly. Instead, I clean points with a piece of paper card stock pressed between the contacts. Three or four passes is usually enough to restore bright, shiny platinum without nicking it at all.

The fact that your saw idles fine but misses at WOT definitely suggests a bad condenser. A condenser is just an electrolytic capacitor. It's job is to slow down the time it takes to discharge the spark as the field collapses once the magnet passes the coil, which is more critical at higher RPM's than lower ones. Electrolytes break down over time. What's happening is that the spark is getting to the plug well before the fuel does, and you're getting alternate misses and detonations on subsequent rotations of the crank. Replace the condenser and see if that doesn't clean things up. I'm betting that it will.

The method you describe will work fine as long as you are only dealing with a thin layer of corrision from sitting, however filing is a necessary evil to restore burnt and pitted contacts. But as you correctly indicate and for the reasons you stated absolutely no more should be taken than needed to creat a flat surface. The contact faces should be flat and matched to fit together fully, not tipped one way or the other as well. This can be achieved by slightly bending the movable contact to fit the stationary one. Of course just replacing burnt points and condenser is the better solution but not always an option on some older equipment.

 

[ckelp]

i'm a dumbass

re set the points for .014" still ran like crap. got a completely stupid idea and replaced the plug..
what do you know it four strokes at WOT like a champ
the plug said "bosnia" i figured this was the problem...

 

[madhatte]

The method you describe will work fine as long as you are only dealing with a thin layer of corrision from sitting, however filing is a necessary evil to restore burnt and pitted contacts. But as you correctly indicate and for the reasons you stated absolutely no more should be taken than needed to creat a flat surface. The contact faces should be flat and matched to fit together fully, not tipped one way or the other as well. This can be achieved by slightly bending the movable contact to fit the stationary one. Of course just replacing burnt points and condenser is the better solution but not always an option on some older equipment.

Your point... errr, "point"... uhh, "points"? -- is well-considered. I haven't yet had to just grit my teeth and file instead of replacing the part. I imagine that I will someday, and I will think back on this and grumble, wishing that I could just find the obsolete part I need.

 

[Cantdog]

Your point... errr, "point"... uhh, "points"? -- is well-considered. I haven't yet had to just grit my teeth and file instead of replacing the part. I imagine that I will someday, and I will think back on this and grumble, wishing that I could just find the obsolete part I need.

Yep they can be brought back a couple times but eventually they will be done in...that's why I don't throw away any hard to find points if they have any life left in them....they might just be difference between running or not.

 

[67L36Driver]

I've done about twenty sets of points in the past year on my stable of junkers. I don't think any of them had platinum coating that I could tell. Mostly the contacts are tungsten I suppose and harder than the hinges of hell. I use the edge of a hard arkansas stone and cutting oil to get them flat and it takes a while. The Sears points file I have is useless.

A Dremmel cut off disc is faster but hard to control for finished flat surface.