Fuel economy and float questions
crassius
Well-Known Member
- Local time
- 1:01 AM
- Joined
- Jul 23, 2012
- Messages
- 4,550
yeah, but I'm getting a surprising amount of repair work for the rainy weather
also, as a repair guy, I can't just throw on a new mag without knowing why the old one doesn't work, and if it is fixable - I can't be like the modern auto guys that just keep charging customers for parts until they find the one that fixes it
if it is a short inside the coil that only shows up at certain temps, I don't know how to test for that
also, as a repair guy, I can't just throw on a new mag without knowing why the old one doesn't work, and if it is fixable - I can't be like the modern auto guys that just keep charging customers for parts until they find the one that fixes it
if it is a short inside the coil that only shows up at certain temps, I don't know how to test for that
Easiest way to start is probably get a magneto from a bike you know is running fine in the same weather, then swap mags to see if it even is the magneto, then maybe do some electrical test before, during, and after a ride. Especially after it shuts off.
crassius
Well-Known Member
- Local time
- 1:01 AM
- Joined
- Jul 23, 2012
- Messages
- 4,550
no testing to do, as it self-heals before I can get off it - it quits dead, I pull clutch, coast 50 feet, let out clutch and it runs smooth with good power for 1/2 block and quits dead - can do that for miles with no change
if replacing mag fixes it, I'll try putting mag in the machine I built for testing strength & timing of CDIs to see if I can find what's going on
if replacing mag fixes it, I'll try putting mag in the machine I built for testing strength & timing of CDIs to see if I can find what's going on
KCvale
In memory of KCvale 1959 - 2019
You can test the electrical system with an Ohm meter.
http://kcsbikes.com/topic.asp?TOPIC_ID=623
It doesn't sound electrical to me though, sounds more like a 'slow fuel' issue,
meaning your not getting enough fuel flow to keep up with what the engine wants.
The gas cap, in tank petcock fuel filter, secondary filter, or your gas tank simply mounted too low can cause this.
http://kcsbikes.com/topic.asp?TOPIC_ID=623
It doesn't sound electrical to me though, sounds more like a 'slow fuel' issue,
meaning your not getting enough fuel flow to keep up with what the engine wants.
The gas cap, in tank petcock fuel filter, secondary filter, or your gas tank simply mounted too low can cause this.
crassius
Well-Known Member
- Local time
- 1:01 AM
- Joined
- Jul 23, 2012
- Messages
- 4,550
I think I found it yesterday, but not sure yet till weather and workload cooperate for testing.
Looked at mag and had a lot of oil in there. For last 2 or 3 years, factories have been drilling the mag mount holes right through into the inside of the case, so that the flat side of the armature is all that seals those holes. In cases where the armature is a bit crooked and hits the case at other points, I've had to put 4 thin washers between armature and case so that all 4 screws will seal.
I pulled mag off & fitted a new one and think that may work now, but didn't look closely at old mag. Later, I noticed that the 4 rivets had never been seated into the armature, leaving needle sharp points on the case side and smooth rods out the front. There were some burn marks around the rivet that ground was soldered to and around some of the points. I'm thinking the return path of spark was arcing there and got hot enough for the ground to fail.
I put about 8 or 10 tons on those rivets and resoldered ground wire. Now all is straight and flat, so I'm thinking it will be OK when I get it back into the bike.
The mystery came from the fact that the meter didn't push enough voltage to cause the arc, so always read just right when testing. I'll post again if it fails.
Looked at mag and had a lot of oil in there. For last 2 or 3 years, factories have been drilling the mag mount holes right through into the inside of the case, so that the flat side of the armature is all that seals those holes. In cases where the armature is a bit crooked and hits the case at other points, I've had to put 4 thin washers between armature and case so that all 4 screws will seal.
I pulled mag off & fitted a new one and think that may work now, but didn't look closely at old mag. Later, I noticed that the 4 rivets had never been seated into the armature, leaving needle sharp points on the case side and smooth rods out the front. There were some burn marks around the rivet that ground was soldered to and around some of the points. I'm thinking the return path of spark was arcing there and got hot enough for the ground to fail.
I put about 8 or 10 tons on those rivets and resoldered ground wire. Now all is straight and flat, so I'm thinking it will be OK when I get it back into the bike.
The mystery came from the fact that the meter didn't push enough voltage to cause the arc, so always read just right when testing. I'll post again if it fails.
crassius
Well-Known Member
- Local time
- 1:01 AM
- Joined
- Jul 23, 2012
- Messages
- 4,550
got some time today - I hog out sprockets to fit over hub caps on coaster wheels for $8 and have a guy that builds cheap coaster bikes that I do sprockets for, he has 6 here to do, but called and said he won't need them till next week after all
so, with weather not bad today I put all original parts back on problem bike and everything seems to work now - will need to ride more to be sure the repaired mag will stay healthy, but I think it's done
so, with weather not bad today I put all original parts back on problem bike and everything seems to work now - will need to ride more to be sure the repaired mag will stay healthy, but I think it's done
