DominicM
XS400 Member
Alright, I normally just read all different forums in search of an answer but this time I need some specific help so I decided to sign up.
I've got a 1980 xs400 sg (special). This is a bike my step dad bought for 600. Basically a driver bike while all our other bikes are not running. Well this is no daily driver any more. This has turned into a project. When he bought it the guy jumped it and my step dad rode it around a little. He took it home and fiddled with it, then took it to a dealership to get tires and an expensive battery. They obviously didn't check the charging system and we didn't either. He assumed that the battery was the problem as most people seem to do. We rode it around some without any problems. Then one day I'm about to go for a ride and it stalled out 2-3 times in the driveway. Then about 1/4 - 1/2 mile from my house at a red light at a busy intersection it stalled again. Electric start didn't work (didn't work to begin with) and when I went to kick it, there was no compression, no resistance. So I pushed it over to the sidewalk and to this parking lot. My mom had to come pick me up in my van. This is my first time working on CDI ignition and my first in depth electrical diagnosis. It's driving me nuts.
So far I've tested a number of things but these 3 things don't add up (or maybe they do to one of you guys):
I checked resistance at stator - 0.8 ohms, all 3 phases (pretty close to manual specs)
I checked AC Volts at stator with bike running - about 10v at idle and about 12v + or - with increase in RPM, all 3 phases (no where near voltage needed to charge battery)
Battery with bike off is 12.8v and running with RPM increase it drops down to 10v and sporadically goes up and down, as low as 5v
I also tested the stator wires to ground and none went to ground (it read OL, which is good)
It seems like it's not working somewhere from the alternator assembly to the harness because it should put out a good 50 volts before the r/r
When I took the stator cover off, it poured out about 1.5 qts of oil (looked a little dirty, but I had just changed the oil within last couple weeks). Is that amount of oil normal?
Also some wires were frayed on the stator just outside the case, but I taped them up. Could this have created a short?
And I put a screwdriver on the rotor magnets and it didn't seem to be very strong. Could the magnets be bad or not producing enough electricity?
Can the electric starter still run good if there's oil inside and on the magnets?
And if there's a lot of side to side play does that mean the bearings in the starter clutch are shot and it won't turn the engine over anyway?
Can somebody help me straighten all this out?
Thanks in advance
I've got a 1980 xs400 sg (special). This is a bike my step dad bought for 600. Basically a driver bike while all our other bikes are not running. Well this is no daily driver any more. This has turned into a project. When he bought it the guy jumped it and my step dad rode it around a little. He took it home and fiddled with it, then took it to a dealership to get tires and an expensive battery. They obviously didn't check the charging system and we didn't either. He assumed that the battery was the problem as most people seem to do. We rode it around some without any problems. Then one day I'm about to go for a ride and it stalled out 2-3 times in the driveway. Then about 1/4 - 1/2 mile from my house at a red light at a busy intersection it stalled again. Electric start didn't work (didn't work to begin with) and when I went to kick it, there was no compression, no resistance. So I pushed it over to the sidewalk and to this parking lot. My mom had to come pick me up in my van. This is my first time working on CDI ignition and my first in depth electrical diagnosis. It's driving me nuts.
So far I've tested a number of things but these 3 things don't add up (or maybe they do to one of you guys):
I checked resistance at stator - 0.8 ohms, all 3 phases (pretty close to manual specs)
I checked AC Volts at stator with bike running - about 10v at idle and about 12v + or - with increase in RPM, all 3 phases (no where near voltage needed to charge battery)
Battery with bike off is 12.8v and running with RPM increase it drops down to 10v and sporadically goes up and down, as low as 5v
I also tested the stator wires to ground and none went to ground (it read OL, which is good)
It seems like it's not working somewhere from the alternator assembly to the harness because it should put out a good 50 volts before the r/r
When I took the stator cover off, it poured out about 1.5 qts of oil (looked a little dirty, but I had just changed the oil within last couple weeks). Is that amount of oil normal?
Also some wires were frayed on the stator just outside the case, but I taped them up. Could this have created a short?
And I put a screwdriver on the rotor magnets and it didn't seem to be very strong. Could the magnets be bad or not producing enough electricity?
Can the electric starter still run good if there's oil inside and on the magnets?
And if there's a lot of side to side play does that mean the bearings in the starter clutch are shot and it won't turn the engine over anyway?
Can somebody help me straighten all this out?
Thanks in advance