Diagnosing charging system

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

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):

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Cool Beans, Lets get started, (ps Welcome to the group!!!!)

I checked resistance at stator - 0.8 ohms, all 3 phases (pretty close to manual specs)

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Good place to start, I seen the bottom question, so I know you have ID the problem, hold on we are getting there!

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)

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Yep not good!

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

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Yup, its a flaky wire, periodically making enough a connections to do something, then it dies! It can't handle it!

I also tested the stator wires to ground and none went to ground (it read OL, which is good)

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Yup not shorting out! OL = Open Loop,

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

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Regulator Recitfier Good eye!

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?

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1.5 qts? that is a lot, when you took out the oil, it should have = no more than total of 2.3 liters, (slightly more than 2.2 quarts) total for the crankcase. Oil does lubricate the Stator side of the engine. It is possible that a PO would have it running, and then shut it down, and think it was low, then bring it up to level by topping it off, which with the oil still equally distributed thoughout the case, might not have given it time to drain. Important to always double check oil level once ever 2 fuel ups, or more often if you have leaks. (I just got my bike not to leak visibly between trips!) now to determine if its burning oil. (sorry just over explaining)

Also some wires were frayed on the stator just outside the case, but I taped them up. Could this have created a short?

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Eureka! You have found it! This is the problem. There are 3 or more systems of how to replace these wires, for the record I recommend Drewpy's re-wire on page one of this web-site forum (do all 5 from the stator/field coil), and listed in the Tech tab on top this page, under electricity, re-wire. Then there is a segment on just the stator section. Of course There is Drewcifer's, and of coarse Sbondini. Its really easy as long as you have the gaskets, and stuff like that. and you get to check out the starter clutch, and things like that! (I have more hints/tips but I will wait to see where you at with electrical skills)

Tobie

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?

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fix previous thing first, that will be fix then.

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?

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Yup The first web site that Willem talks about is the Wetclutch oil, Key standard is "JASC MA" alot of us use oil from walmart for $3.49 Shell Rotella-t 15-40, (since your in the US I usally get the 5 quart for $12.97, with price matching Menards has also sell this for the same price, at least in my local area.) Oil also provide rust protection fro the inside parts!

Thanks arfstrom for the reply. I will look into the re-wire. Where should I get the connectors? like the white one that connects to the harness. Or if I reuse those, how do I remove the metal connectors inside? Will just regular primary wire work?
Also the wires that were frayed were tinned (I'm pretty sure) since they were silver looking, does that make a difference?


Also I was talking about the starter, not stator in that last bit:
"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?"

The electric starter has a few oil seals before the inside of the starter and everyone I ask (friends and relatives) say it doesn't matter if oil gets inside, yet when I pulled the starter apart it had carbon mixed with oil gunked up everywhere (on the commutators and brushes). I'm wondering if it's worth it to take out the middle part of the starter because I can see some gunk down the sides

Where should I get the connectors? like the white one that connects to the harness. Or if I reuse those, how do I remove the metal connectors inside? Will just regular primary wire work?

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I picked up mine at Mikesxs.com They have a few varieties. since you have a 400SG, go and down load the colorized wire diagram, this is a great start, since you have 5 wires from the stator/field coil, then you have one for the nuetral safety switch, and oilpressure switch in the bundle. I was able to buy "Tinned wire" at Menards, I am sure you have a Lowes or other home type store like those in your neighbor hood. I am sure the US wire guage is listed on that re-wire, Its just too early to run out to the garage and see what I got, I want to guess it was 16 gauge. Then I was able to get a roll of each color, Its an over kill, but if/when you sell the bike the closer to the wire standards you can keep the work, will keep it simple for future diagnosis of issues.

Or if I reuse those, how do I remove the metal connectors inside? Will just regular primary wire work?

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Re-use is always possible. If you can find the Metal blade connectors, and get a real crimping pliers, they will come with the connectors from Mikesxs, you will still need a real crimping pliers.

To remove -- I used a finishing nail, then I used a hammer to pound flat the narrow side, You can use that to reach up inside the front, to the metal spring out, to push that in, and slide out the existing connector. as long as your there, get the heat shrink tubing, and then look for the Vinyl tape, that is self-fusing. (google magictape, has same properties) Get 2 to 3 rolls (3 to 5 bucks a roll (well worth it)) there is small GB shrink tubing, comes in 4 inch sections, and can be cut down to the 1 to 2 inches for weather proofing that will hold 1 wire, then I picked up about a 4 foot section, for the long run from the stator/FC to the first connection point Needs to be big enough to hold 4 to 5 wires. Note the Tinned wire is for use in Marine applications, so provides some better connectivity.

Also I was talking about the starter, not stator in that last bit:
"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?"

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Damm attention to detail. If there is that much oil up there, I don't know yet. I have a new starter rebuild kit, I haven't started that project yet. Maybe tomorrow I will rip it out, and take care of it now. When I rebuilt the crankcase bottom in the last 2 years, I don't remember any oil dripping from it. and it is such a small unit. It doesn't make sense to have that much in there.

The electric starter has a few oil seals before the inside of the starter and everyone I ask (friends and relatives) say it doesn't matter if oil gets inside, yet when I pulled the starter apart it had carbon mixed with oil gunked up everywhere (on the commutators and brushes). I'm wondering if it's worth it to take out the middle part of the starter because I can see some gunk down the sides

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I will take a ton of Pics when I do this. I just the Yamaha plate to be oil tight, now that I am doing the starter, I think I will need to take the starter clutch off and all that, So I got my amazon xs400 starter rebuild kit with all the seals, and brushes, and all that. So the kit only cost me 15 bucks from amazon, if your here now, get it now.
http://www.amazon.com/gp/product/B004UASOWW/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1
My starter runs periodically since my starter button fell out, (mikesxs horn button) end of spring semester, A huge rain storm made it un-avoidable to go home after work at 10pm, the last 2 blocks of that trip(30miles) the starter was activated, and I could hear it rev up with the increase of the bike RPMS. Bad deal, now it works once every 5 times maybe.
http://www.menards.com/main/electri...s/8-inch-crimping-pliers/p-1460440-c-6455.htm

http://www.menards.com/main/electri...l-heat-shrink-tubing-polyolefin/p-1490666.htm Then I think I found the Thick wall heat shrink tubing, I think did buy the roll of heat shrink, but I used one from a local company that deals with electronic stuff. Either way You will be happy with the results.

I hope that answers your questions, I took Dewpies spreadsheet, pasted it to something I can work with, then put the american conversions.

http://www.xs400.com/forum/showpost.php?p=93569&postcount=4

See I was thinking there was a breather hole from the crankcase up into this starter space. I was suspecting that the bike might have been held upside down, for a period of time for it to accumlate a 1.5 quts of oil. My assumption is that that was there for moisture control, the some oil may splash up there, but its not going to get into the starter housing.
hope that helps with your investigations.
Tobie

Okay, like I thought, nope no oil in the starter. there is a hole in the crankcase which could leak oil up into the starter zone, see pic from Westerberg story. (similar name posted today or yesterday.)

Wire was 16 gauge Tinned. Perhaps when I wake up tomorrow, I will post all my starter pics in my albums. I hope this helps. Here is a collection of Pics. The cardboard bottom, you can see how much liquid drained out of the starter when I took it apart. (very little)

The 16 gauge wire, I did buy one of each color, I think I had to settle for one color that wasn't tinned, but it was for like one of the sensors, since the sensor to the connector, isn't submerged in oil, I don't suspect that one needs to be tinned. I also don't think that sensor wires use a lot wattage, is it doesn't need to thicker gauge wire, so they could be somewhat smaller diameter wire, compared to the Starter which uses major amount of voltage/watts=more power=thicker wire/insulator/more conductors(smaller wires in bundle)stiffer wires.

Thanks again for all the help.

The generator housing has oil splashed inside it for lubrication, and 1.5 qts may be fine since the bike was on its side stand. Then the electric starter has a small sprocket that goes on that shaft that has a chain and a bigger sprocket. Oil splashes all the way up there too. The starter has 3 oil seals before you get to the actual inside of the starter. When these wear out oil can leak past, get into the motor, and continue on to the commutator and brushes. I believe this is no good for the starter. Definitely no good for the commutator and brushes. I think if oil gunks up those magnets in the starter it won't generate a lot of electricity making it less efficient (and it isn't oil in there it's sticky grime, which can clog some stuff up). Should I pull the middle apart to clean off the gunked up starter magnets and stuff?

It kinda sounds like I answered my own question there but I want to know what other people think because me and my step dad disagree about it.

I used gasoline to rinse the starter guts. Except for some old grease on the one side, it was really dry in there.

This my slide, It seems mine are more faster responding.
Tobie

First time I used my tablet to copy something to youtube, I hope it works somehow.