Sat Dec 24, 2005 3:32 pm
Last night, I was cussing up a blue streak while I was trying to clean out the barn quick before everything started to melt and turn my field into mud and it was all I could to run by Mc 100 spreader even down hill!!! Going up the hill, I had to disengauge the wheel drives and climb up in first with the trottle wide open. Now keep in mind, that I just did this September and the cub ran just fine but now it seemed like I had more power from my 1450 lawn tractor that I used to use to pull my spreader
. Anyway I started looking over some overhaul kits and called a buddy that does machine work to price everything and was a little shell shocked (I'm just about as cheap as they come). So today on just a whim, I decided to see if I could squeze out some more power by advancing timing a little. Well the trick was to retard it and while I was doing so, it started running a little faster and much smoother! Tried it out and yes sir much more power. I can climb the grade with it at idle in second gear with the spreader.....minus half a load. Could there be any problems if I have it retarded too much (timing) and should this be expected (requiring a timing adjustment) during the winter months? And finally, how in the world do you check the timing.....I have a timing light, but it runs off 12 volts. Should I just park next to the truck and run off that battery and clamp around #1 with the pickup lead? Could I remove the 1/8 pipe plug and make an adapter to fit the manifold right by the carb to conduct the tuning by vacuum that was described in an earlier post or is there some other way to hook up for this test? Merry Christmas too all and to all a good night! God Bless and have a Happy New Year!
Sat Dec 24, 2005 4:01 pm
rufus, your method of checking the timing will work, but how to do it depends on what type igniton and crank pulley you have. If it's a magneto, when turning it with a crank you should hear the impulse snap just as the pointer passes the TDC timing mark. If it's a distributor you the points should just open giveing a spark at the TDC mark. If your tractor originally came with a magneto, whether it now has a distributor or magneto, the pulley will only have one mark. If it origanilly came wiith a distributoir, it will have 2 marks, the first one being 13 degrees advance and the second one being TDC.With the engine running you set it to the second one using a timing light. If the pulley only has one mark you will need a timing light that has a dwell adjust knob on it.
Regarding the rest of your question, no, it is not normal to have to reset the timing over the winter. Before I do too much fiddling with the timeing I would put in new spark plugs, and repalce the gasoline with fresh. old gas doesn't burn well.
Sun Dec 25, 2005 8:51 pm
There is a section in the book for cold or initial timing. It is used to time an engine after removing the distributor to set an intial time to get the engine started and follow up with a timing light to tweeek it using a timing light. I have found that if I am careful the timing falls in just right and doesn't need tweeking. With the ignition off turn it to top dead center # 1 piston (the one nearest the radiator) The pointer should line up with the mark on the pulleyand the rotor should point to where the #1 spark plug wire is when the cap is on. This is done after adjusting the points. Any way next loosen the distributor mounting fastener. Rotate your dist till the points just break. Keep that adjustmentand tighten the dist.
You will find this in the manuals on Rudi's site.
Mon Dec 26, 2005 12:14 pm
one thing i have not seen mentioned. as the cam in the distributor or mag wears the rubbing block on the points the timing will be advanced because the dwell angle is increased. this will result in reduced power. resetting the timing WILL reduce the symptoms despite the increased dwell angle. when the rubbing block wears further, the symtoms will either recur or the tractor will stop and not restart. at some point the gap at the points becomes so small no timing adjustment will help.
timing should not change by itself. when new ignition parts are installed, if those parts are adjusted to specifications, the timing will not need adjusted. look to the points and condensor first for ignition problems. points for out of time, condensor for weak spark.
when working with a mag ignition one should avoid causing the mag to trip and cause a spark unless there is a load on the spark plug end of the wire. if there is no load where the spark plug should be the spark will find the path of least resistance. that is usually through the coil windings. repeated flashing of the spark through the coil will cause a carbon track to form, ruining the mag.
when replacing points use the proper lubricant on the rubbing block and keep on cubbing.
Mon Dec 26, 2005 1:32 pm
A couple of other points:
1) 12V timing ight will probably work just ine on your 6V system. If it soesn't, then you can use a 12V bvattery or another 12V vehicke, like you said.
2) If you happen to have only 1 timning mark on your pulley(like mine), this is the "retarded" spark timing mark. To time an engine that uses a distributor ignition, using a timing light, make sure the engine revs are low enough that the advance mechanism will keep the points fully retarded. This is usually below 180 or 200RPM, as I recall. As long as the advance mechanism is working properly, this will work.
Fri Dec 30, 2005 12:05 am
Thanks to all that gave me advice but I finally narrowed the power problem down. After just about giving up, I finally found my timing light and when I hooked it all up and went to take a look at the timing mark, the light wouldn't fire (It does work on 6 v) here the weight of the clip on #1 pulled the wire clean out of the distributor. I guess the plug is fouled because after I put it back on and started the tractor I pulled it off while running and the engine didn't seem to react at all. Thanks again for all your help.
Fri Dec 30, 2005 11:19 pm
Here are a couple bits of info, I doubt there are any 6Vt timing lignts around anymore. They were prone to burning out and werent much good. You can use a 12 Vt timing light on any contact point ignition system as long as you use a 12 vt supply, like a 12 vt battery or a 12vt charger works well. I would suspect that the point gap would cause some of the improper advancement but thinking further i would think that the distributer got turned somehow. or if you have a mag the impulse got stuck and forced the mag to rotate some before poping loose.. In any gas engine the further advanced you can run the engine without any ignition knocking or valve pinging you will develope more power. but remember it may be a little hard starting. The timing marks on the front pulley are where the engineers found thet the engine would start and run the best in most areas. I have a cub that is advanced 20 deg and runs with the farmall A's in the pulling contest. It has to be the timing, and prooves that advancing the timing will produce more power to a point. George Willer and I discussed this at the second cub workshop at Albies.
Mon Jan 09, 2006 12:03 pm
I only have one timing mark on my pully and from what I understand, that's TDC so couldn't I just take a tape measure and mark where the advance setting is and file a new notch in there for my second mark? How far and what direction should this be done?
Mon Jan 09, 2006 12:33 pm
Yes you can if you want to. Just be sure that the mark you file will pass the pointer ahead of the existing mark. I believe the distance is listed in another post here on the forum.
Mon Jan 09, 2006 1:58 pm
Just read the post on timing and now I wounder could I have my govener out 180 degrees. I did not pay attention to that when I removed the unit. Is this possible or am I ok either way?
Mon Jan 09, 2006 4:38 pm
Yes, it's possible
Wire the plugs 180 and see if that gets the tractor running. If the tractor run that way, please fix the timing for the potential next owner.
Wed Jan 11, 2006 7:36 am
Ok. Got to jump in here since I've had timing issues with my mageneto before. Back to what John was saying. My trac came with a magneto but was convereted to battery ignition. The way I've timed in the past is to ground the 1st plug, crank the engine by hand and watch for a spark. If she sparks at or close to the notch on the pulley, I'm happy.
If I'm reading these posts correctly, the hand method will get me close but not accurate. The proper way I should be doing this then is to run at idle and time with the light at TDC?
Wed Jan 11, 2006 7:56 am
I would say if it runs good, then your method is as good as any.
If you want to use a light, and you only have the single mark(as I do) then yes, you have to do it at idle.
Wed Jan 11, 2006 8:25 am
A magneto advances as soon as it comes off the impulse. So even at idle it will be advanced and should no longer fire at the single notch. Just static time a mag. Checking it running will verify the advance is working because the notch will not line up.
Wed Jan 11, 2006 8:30 am
Right, but I think Scotty has a distributor, not a Magneto.
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