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View Full Version : Adjusting points while running?



bikerinthenight
07-20-2005, 07:58 PM
Reason I`m asking is because I have done ALOT of work on the old honda 750 fours, and found that regaurdless if you use a feeler gauge for the points, and a timming light for the timming, it will still run better if you adjust the points while running, and adjust them to where it idles at its highest and lock them down. then of course adjust the idle if needed. I`ve done this on several friends 750 fours, and ALL said they ran much stronger, and smoother. I believe it is do to play in the crank bearings/upper end, points cam wear, ect. What would happen if I tried it with the ole shovelhead? like I say, I would turn them which ever way needed until it idles the best/highest, which usually means its firing at the "perfect" time. thoughts?

Wide
07-20-2005, 08:06 PM
Sure try it, I always just do it static

let us know how it works out :D

88FLHTC
07-20-2005, 08:17 PM
:unsure: Ummm...sure, you can adjust the timing when it's running by moving the breaker plate, But I'm not quite sure if I'd stick a feeler guage in the points while it's running..

Like Wide says..try it and see what happens :D

Stoney
07-20-2005, 08:25 PM
In the old "points" days I used to put a rolling paper in between the contacts,hold the cam in full advanced position & turn the plate until you could pull out the paper without ripping it. Got used to doing that on the side of the road with whatever was at hand.Always worked perfectly! bottomsup

Wide
07-20-2005, 08:29 PM
:unsure: Ummm...sure, you can adjust the timing when it's running by moving the breaker plate, But I'm not quite sure if I'd stick a feeler guage in the points while it's running..

Like Wide says..try it and see what happens :D


You use a dwell meter to read the gap duration :D

junior
07-20-2005, 08:55 PM
adjusting them until it idles "best" is not really a good idea, imho....what you are doing is likely opening the gap a bit, which then advances the timing, which then causes the idle to speed up. if you then readjust the timing to correct specs, your dwell angle is likely too small (points open too far) and your coil saturation time is lessened...

in general, the harley point system is about as exotic as a briggs and stratton. the point being is that as stoney mentioned, setting them statically is more than accurate enough for it to work correctly. however, as with all things harley- you should go ahead and do whatever it is that you think is right....

fwiw-

j

wreckerman
07-20-2005, 10:18 PM
adjusting them until it idles "best" is not really a good idea, imho....what you are doing is likely opening the gap a bit, which then advances the timing, which then causes the idle to speed up. if you then readjust the timing to correct specs, your dwell angle is likely too small (points open too far) and your coil saturation time is lessened...

in general, the harley point system is about as exotic as a briggs and stratton. the point being is that as stoney mentioned, setting them statically is more than accurate enough for it to work correctly. however, as with all things harley- you should go ahead and do whatever it is that you think is right....

fwiw-

j

junior is right on with this post , and i agree , but i also use a dwell meter when setting points for best results that way it will be takening in any play that it might have

bikerinthenight
07-21-2005, 03:34 AM
Well what got me started on this thought was the fact that I used to pull away from a friend of mine that has a 1974 honda 750 four, and one day his points started acting up at another friends house that did`nt have a timming light or feeler gauges, anyway, after cleaning up his points i said he dude, I`ll just set them by ear for now. so after i did that we went out to test it, and he started giving me hell, it ran better than it ever had. so a couple days later he brung it over and I decided to get out the timming light and feeler gauges to check it out, and it was not right, the timming was slightly off according to the light, and the points were infact wider than they should have been acording to the book, so we set it acording to the specs, and again, i could easily walk away from him, so he ask me if I would do the points like I did before, so I did, and wala, it was running like a bat out of hell, and again giving me all I could handle. so every since then, I done several other 750 fours that way, and all that I`ve done, have ended up running stronger than ever, so i know its not a coincedence(sp?) anyway, lately I`ve been thinking about what would happen if I did it on mine. especialy since last weekend he started showing off by trying to blow by me, which did`nt happen, but I had to give it ALL i had to keep it from happening. I know that dwell and gap will probley end up slightly off, but it did`nt matter with them other bikes, infact it helped. my biggest fear is burning a hole in a piston or something awfull like that. I`m not trying to be the fastest or worried about beating a old honda, but just wondering if I`m leaving some performance on the table, by not giving it a try. one other thing I should mention, is that when I did them points by ear, there was a range in point movment that did`nt seam to make a differance, so I moved them to where the gap would be less, and stopped just before you could hear the motor idle start to go down. I dont know of that made any sence, but how about this, for example the points did`nt change the motor rpm when moving them from .018 to say .022, so I put them closer to the .018 than the .022. I knew which way was opening them vs closing them, so when I got the highest idle, I made sure they were at the smallest gap, instead of the widest gap when idleing at its highest. also when I checked the honda points, they were only about .003off, and the timming was just slightly off centered. so i cant help but think that a motor with many miles, may not run best with brand new settings? anyway, just cant stop thinking about it. but then again, if it aint broke,,,dont fix it :rolleyes:

Wide
07-21-2005, 03:58 AM
bikerinthenight

This is an old deal thats been going on since day 1 & only can cause problems.

When you increase the gap the spark will intensefy, (this goes for plugs & points) this causes a resistance build up at the coil which will at some time toast it along with burning the plug electrodes, you know what follows, overheating & detonition.

You could in theory just pull your spark plug wires off 1/2" & get the same results, this is how we used to start the old flattys, Knucks & Pans when they fouled plugs.

I always make my electrical systems spot on & make the hp where it's intended.

Just dont want to see anyone toast a motor :D