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t125 electrical issues maybe? help

1.2K views 11 replies 5 participants last post by  WintrSol  
#1 ยท
well... im having trouble with my 125 again... put over 200 miles on it rode it all over town, ran fine and then of course something brakes. it's actually been screwed up for a few weeks i just haven't had the time to post about it, and i figured i could fix the problem myself..

basically, what it SEEMS like is that one of the cylinders is firing intermittently, but not constantly. i have no way of testing if the plugs are constantly getting spark when needed or if it's cutting out..

the engine basically revs and blinks out.. RRrr rrrR RRR Rr r R R R R rrrrr RRR RRR r rR rR R R Rr R r r like so... then dies

it SEEMS like i have a wire grounding out somewhere...

nope... been over it 5 times with a fine tooth comb outside in the daylight so i can see every ****ed inch of it..

i replaced the condenser with 2 other ones i had laying around, no luck, I know for a fact that both coils are good, because i can switch the wires into the coils out and the opposite one fires...

i finally deduced that a wire going to one of the coils was bad so i ran another length of wire from the condenser to the coil, and it got spark finally...

so... i put it all back together and it STILL did the same ****ed thing...

SOme of you may remember that i said i had a problem months and months ago with the blinker actuator blinking the motor as well as the headlight when i use my signals, and we never came up with a solution to that...

i'm beginning to think my ****ed stator is bad or something.. that's the only thing it could possibly be at this point right?

coils are good, condensers are good, wiring is good... rectifier is grounded properly, it doesn't nor has it ever had a regulator,

the only thing i can think of is the stator itself, or the points...

what would bad points do to a bike???? how would it run if one of the points was going out?

that's the thing though.. it gets spark to the plugs...

is there any OTHER sort of bs within the engine that would cause it to cut out like that and die?

something that would ACT electrical but is actually mechanical? like maybe no compression in a piston? or motor oil leaking into the cylinder? i'm at a frikn loss at this point and i'm out 2 bikes...



help ? lol
 
#3 ยท
Let's see if I understand you correctly... You're saying that one cylinder is firing fine while the other is firing intermittently...that's what I understand the bike is doing.

The stator shouldn't be the problem... if it is putting out too little current it will affect both cylinders. Same with the rectifier/
Everything is one circuit until it gets to the coils which is where the current is split for each cylinder. From that point each cylinder is operated by a different coil, coil wire and sparkplug.
The fuel, based on your observations, doesn't appear to be the problem.

I'm like WintrSol, the first thing I'd do is to replace BOTH sparkplugs. If the problem persists, I'd replace the coil on the cylinder that is missing. Coils, even new ones, go bad without warning and can partially work causing poor firing.

CD
 
#4 ยท
wintr.. the problem occurs before the plugs and before the coils. there are 3 wires from the coils. a thick black one with the plug cap, an orange one,

and,

one has a black / yellow wire, and the other has a blue/white wire.

one side wasn't getting spark and the other side was, so i swapped the blue/white - black/yellow with each other, and the other side got spark and the other didn't.. so with that, i deduced that the yellow/black wire was bad.. so i routed a brand new wire from the condenser to the coil and that fixed the problem

so.. now both sides get spark from what i can tell... the thing is, i don't know that both sides ALWAYS get spark when it's needed... i still think it's cutting out here and there...

I cant test the spark at kick start speed...

the ONLY way i have to test the spark now is to shove a screwdriver in the plug cap and watch for the arc on a header or something, which is hard when you're also trying to kick the thing over, so more often than not i end up sticking my finger in the plug socket and kicking it over until it sparks....

it's not the most preferable way... by the way, it's only a 6v bike, so.. it doesn't hurt.. no way in hell i'd do that on a 12v bike.. tried it once on my 500 and it nearly knocked me on my ass, and never did it again.

anyway, though it's not that bad, i still don't want to kick it through an entire kick as if i were trying to start it, in order to see if it sparks every time the rotor hits the points.. that WOULD hurt... there's no other way for me to test.. so i don't know that it IS getting spark when it should.

either way, it doesn't run at all now... it almost fired once earlier and ran for about 4 seconds and blinked out....

at first it was just... running intermittently... RRRrrrrRRrrrRrRRRRRR

now, it's worse..

RRRR R RRRRRRRR R RRRRRRRR R R dead.....

as if someone is plugging and unplugging the battery altogether...

but with that said, i STILL don't know for certain that it's an electrical problem....

but i assume it is because of how it's acting...

if one cyl isn't firing, the bike SHOULD still fire up and run...

it will flood out and start spewing gas out of the pipes and carb, but.. it'll run...

i know that for a fact! the only reason is because when i busted the piston on my other bike, it still ran on the one cylinder the 5 or so miles back to my house... barely though...

----------------------

clock.... i think i answered these things above....

it's not the coils or plugs i'm positive.... granted i probably do need new plugs, but they only have 200 miles on them.. actually less... i've replaced them 2 times since i got the bike.. the coils work fine when i switch the wires out...

and NOW... both........... coils fire at least when i test them.. not sure about whether they are firing EVERY time the rotor passes...

I had one question though that hasn't been addressed...

what do bad points do to a bike? what are the symptoms of bad points???? ****.. i'd love for it to be something that simple, even after i tore the whole ****ed bike apart and checked every inch of wiring a half dozen times, and replaced the condensers a few times, and all the other stuff i listed previously..

either way, i'd bet money on it not being the coils or plugs.. or condenser, or rectifier, and.. apparently not the stator either,

but... i DO think there's something wrong with the stator.. remember what i said about the fact that a maglight flashlight puts out more light than my headlight does, and there's not enough power to use the blinkers, and the blinkers blink the motor too... it does charge the battery in night mode (headlight, tail light, motor, as well as blinkers once in a while and tail light once in a while) but it doesn't have enough juice to run everything accurately..

i don't think it's putting out enough power... that's the only thing i can think of regarding that... a bad stator....

one of the coils in the stator probably has a broken wire or something...

BUT.. yeah.....

that's not going to cause the problem i'm having now...

so.. with that said... damb.

We've pretty much eliminated the ENTIRE electrical system from being faulty with our observations..


WTF else could it be??????

any mechanical **** that causes this??? like... a crack in the head???? a bad ring?

is it possible that the timing is SOOOOOOOOOOOOOO far off that it would do something like that?

the last thing i did to the bike was to take the stator off because it's attached to the cover and all comes off in one piece..


i took it off in order to put a new clutch cable on it..

but then i rode it another 50 miles... all over town in fact...

then pretty much out of nowhere this happened..

with that said, i do remember that the last time i road it, i was trying to ride a wheely from a slow roll.... i did that about 4 times and stopped.... it still ran.. nothing was affected.. i rode it at least 5 miles after i did that...

the next day i went to go somewhere on it and it was doing this ****.....

i dunno.. could i have screwed something IN the motor up when i was trying to ride a wheely?

i didn't slam it too hard or do anything too extreme with it...

i'm just trying to think of anything at all it could possibly be....

oh... also, it's burning oil when it does run... it used to burn oil a lot when i got it running, then it stopped burning oil for a long time.. now it's doing it again...

just... going through anything i can think of that may help solve this...

given what i've done so far,

what would you guys do next... besides douse it in gasoline and set it on fire?

The thought has crossed my mind by the way, but i don't have insurance on it, so.. i wouldn't get anything out of it..

it is however on craigslist and ebay again... we'll see how that turns out..

i'd still like to try to fix it though, because i doubt anyone will buy it... no one bought it when it was running great.. why would they buy it not running..
 
#5 ยท
Bad points would be obviously burnt, or the rubbing blocks worn down so they don't open properly. If the gap is good when they're opened, and the contacts aren't fried, the only other thing that can go wrong with points is for the wire side to short to ground when they're open, and that's really rare.
If one of the plugs was defective, over-tightened, or improperly gapped, the insulator could be cracked, causing intermittent loss of spark.
 
#6 ยท
wintr, it's not the plugs i promise...

i know i wrote a lot in there, but i explained why it cant be the plugs in my first post and in the response. the problem was happening before the plug, and i proved it, and partially fixed it by replacing a wire.... screw it though... i'll take the plug out of my other bike n throw it in there and see what happens.. no point in arguing if i haven't tried replacing the plugs since then. but i really seriously don't think it's the plugs.

As for my question about the points,

My question was more along the lines of "how would the bike act.... if the points were bad?" vs what constitutes as being a bad point.

i was kinda hoping that someone would say "oh.. yeah.. your bike will do that if you have bad points.. change em out and you'll be fine!" lolol

never that easy though i guess...

its worth mentioning too that the point from the right cyl had been sparking and arcing quite a bit in the days leading up to the total failure. usually that means bad condenser..

so after it quit running that was the first thing i swapped out. a few different times and it ends up that the one i first took off was the best one.

i dunno....

I do appreciate the input though, please keep it coming... maybe we'll come up with something before someone buys it.
 
#7 ยท
I bought a spark tester from Autozone, it just sets over the spark plug wire so you can do it while the engine is running. It was less than $10, sounds like it may be worth it in your case to help narrow down the issue.
 
#8 ยท
You should also get a voltmeter, if you haven't one. If it has a way to cancel the auto-range feature, i.e., a fixed range setting, it will update faster (assuming digital, here). That way you can measure the voltage on the supply side of each coil while the engine is running or while kicking it. The voltage will drop some when the points close, but it shouldn't be a lot. You can also measure the voltage on the points side when the points are opened and closed. Careful here, because there will be a couple hundred volt spike when the points open.

Since there may be an issue with the condensers, you can compare them using the ohms setting. with the wires disconnected, connect one lead of the meter to the engine and the other to a condenser. Get a feel for how quickly the value settles on the meter when you reverse the leads a few times. Then, repeat the test on the other condenser - the settling time should be very similar. If they're significantly different, you have either a bad condenser still, or the grounding of one is poor.

I'm starting to wonder if the problem is fuel induction, like a sticking valve - this is a two-stroke, isn't it?
 
#9 ยท
The closing of the points allows a spark of electricity to flow to the plug wires and allows each cylinder to fire. If the points are bad they will have a burnt or flashed look to them. This lack of proper contact will prevent the proper amount of current from flowing to the spark plugs. Typically, the points can be filed or sanded to remove the bad areas of contacts and regapped to correct the problem of reduced spark temporary.

I hope this helps.

CD
 
#10 ยท
wintr

i have a voltmeter, and did in fact test out the ohms of the condensers, just forgot to mention that i did.

i cant do the other thing you said, because it doesn't start at all, and hasn't since before i started doing all the condenser swapping and what not.. i guess i didn't mention that it doesn't run, just gave examples of what it did when it did run..

screw it... it's on ebay and people are bidding on it.. i love the bike, but.. im tired of jackin with it... if i can get 800 out of it, i can really sick out my 500, and sell it too....

then fix the transmission and AC in my Z28...

AC in your car is important to have in Texas starting about now..

as for valves,

there's no valves of any sort on this bike.. it is a 2 stroke, but doesn't even have reed valves on it.
 
#11 ยท
Hi Mitch. I've had a similar problem before. Where the wire attaches to the points, the wires end in a lug which is attached to the points via a very small bolt/nut. My right cylinder points loosened up and the metal lug rotated outward enough to touch the inside of the points cover, shorting it out. WIth the bike vibrating it was intermittent at first, but eventually that cylinder would just not fire at all.

Check each set of points to make sure the wire is secure and not touching any part that is grounded, like the cover. It took me a while to figure this out on my bike, ruined Daytona Bike Week(end) for me. You can make sure that is not the problem by rotating the crank until both points are open before putting on the points cover. Then attach a continuity meter to the wire(s) that go to the points where they attach to the harness (I had to loosen my tank to get up there) and the cover and make sure no current is flowing between them.

Just another possibility that might be worth checking.

Good luck,

Mike
 
#12 ยท
No valves; all done with careful porting, then.
LWRider makes a good point; if those connections are loose at all, the spark will be unreliable. A quality set of points will have two metal strips between that connection and the contact, one is the spring. The crimp/weld of the contact to the spring could be bad, I suppose.