Question using multimeter

[sweetip2000]

anyone know what the resistance is supposed to be for the ignition coil on a 86 honda 250sx ?
what should my multimeter be set to when testing,,,,its a digital multimeter thanks

[Flyingw]

Andy, the setting for resistance is ohms, its the horse shoe looking symbol. Post a pic of the face of your meter.

[HONDA_ATC_FREAK]

I was just messing with testing on my 400ex today like flyingw said it's ohms( the upside down horseshoe looking symbol). When testing like for continuity set it on the lowest setting for ohms on mine it's 200.

[Flyingw]

I always tell guys when buying a meter to spend a few extra bucks and get a meter with auto-ranging. Just turn to resistance and take a reading.

[sweetip2000]

Here a pic of the multimeter. amongst other things I found along the way,,,, I unraveled the cover on the wires to the ignition and found one of the wires had a small chunk of insulation missing... it is not touching anything else metal, was wondering if silicone caulk would be ok to put on there before I put the electrical tape back on.

I keep getting errors when uploading files here. Exlamation points with nothing telling me wtf it means.
Is it a file size issue now ?

[Flyingw]

Electrical tape is just fine

[sweetip2000]

I was just messing with testing on my 400ex today like flyingw said it's ohms( the upside down horseshoe looking symbol). When testing like for continuity set it on the lowest setting for ohms on mine it's 200.


thank you will give it a go

[sweetip2000]

It peaks at .4 to .7 then stays between .1 .2 and .3
the meter is on low setting ohms

[HONDA_ATC_FREAK]

look up oscarmayer or do a search on here for manuals he's got a link to his own site full of manuals you can download what you need there and figure out what your supposed to be reading.

[HONDA_ATC_FREAK]

heres the linkhttp://www.oscarmayer.net/atc/manuals/

[HONDA_ATC_FREAK]

It's 14-3 in the manual except for when you say it peaks it is in spec according to honda, but download the manual anyway and go thru the ignition chapter it will help you out.

[barnett468]

anyone know what the resistance is supposed to be for the ignition coil on a 86 honda 250sx ?
what should my multimeter be set to when testing,,,,its a digital multimeter thanks

ok, i'll give this a shot but it’s confusing . . just take it one line at a time.

1. according to honda there are two different brands of electrical system that came on this bike . . they are ND [which is Nippon Denso], or MITUBA.

2. the nd system exciter coil in the stator should read 50 - 200 ohms.

3. the mituba exciter coil in the stator should read 250 - 400 ohms.

4. if your coil reads from around 225 - 400 ohms, it is a mituba coil and it is good, however, a reading of below 200 would be a little weak . . the higher the number, the more voltage it will produce which is a good thing to a certain point.

5. the nd coil should read no higher than 200 and no lower than 50 . . if it reads higher than 200, it is likely a mituba coil, not an nd one.

6. here’s the problem, unless you know what your system is, if the reading is lower than 200, it does NOT mean it is definitely an nd coil . . it could simply mean that it is a mituba coil that has gone bad anmd the low reading is making it look like an nd coil.

7. there may be some lettering on the stator that says what it is . . the name nd or mituba may also appear on the spark plug coil under the gas tank, unfortunately, if there is a name on the flywheel, it may be covered up by the plsate fixed to the outside.

8. if you can not determine what brand of system it is, and it reads between 50 – 200 ohms, my best guess is that it would be an nd coil and that it would be good because 50 ohms is an unlikely number for a 250 – 400 ohm coil to fall tom but again, it’s just a best guess.


COIL CHECK

Set your ohm meter to 500 ohms.

Disconnect the black wire with the red stripe that comes from the stator.

Connect one end of the meter to that wire.

Connect the other end of the meter to the engine.

If the ohms are less than 200, set your meter to 200 . . You may get a slightly more accurate reading there.

Post the results.

[sweetip2000]

I will get onto downloading those manuals and thanks freak for posting the link. I have the coil here and there are some numbers imprinted on the housing of the unit. TEK Japan 5701. MPO3. That stator wire disconnect should be near the motor case ? I am not near the bike now. Its raining and dark and no electricity running to the stand alone garage.
I will test the stator tomorrow and post the readings here. Thanks for the line by line breakdown, totally awesome info.

[barnett468]

.
I just noticed that I didn't paste all my text from my word program I wrote my post on . . Anyway, my post was a suggestion to check the coil in the stator that generates the voltage for the ignition system also because it will not run if that is bad either.

Sorry that I had to make another post just to tell you this but I don't have an edit button.

[barnett468]

I have the coil here and there are some numbers imprinted on the housing of the unit. TEK Japan 5701. MPO3. That stator wire disconnect should be near the motor case ? I am not near the bike now. Its raining and dark and no electricity running to the stand alone garage.
I will test the stator tomorrow and post the readings here. Thanks for the line by line breakdown, totally awesome info.

No prob, you're welcome.

Unfortunately, i don't know what system that coil is used with but it may be used with both.

The factory spark plug coil under the tank rarely go bad on any of these bikes so if you have a low or no spark problem, my guess is that it is elsewhere in the system.

That bullet connection for the single black wire with the red stripe is shown in the manual on page 14-4 [number at bottom of page] to be right next to the voltage regulator.

[sweetip2000]

I unplugged that bullet connection near the regulator. There are 2 sides to that connector male and female. I tested both. My meter is set to auto. One end of the meter touching connector the other end touching motor where it is not painted.

I got 3 readings from male plug. 7.98 6.5 and ranged between 29 - 40
The female plug was 337

[barnett468]

.
ok, please just answer these yes or no for me.

is you meter digital?

are you saying that you tested the male end three different times and you got three different readings?

are you saying that one reading bounced back and forth between 29 and 40 ohms?

are you saying that you tested the female end a couple times and it read near 337 ohms every time?

if the answer to my last question is yes, then this is the end that comes from the stator and the ignition portion of your stator coil is very good.

also, as a rule of thumb . . the end of a wire that supplies voltage to something will almost always have a female end . . its just the way they seem to do it.

just exactly, in detail, is the problem with the bike?
.

[sweetip2000]

ok, please just answer these yes or no for me.

is you meter digital? Yes

are you saying that you tested the male end three different times and you got three different readings? Yes

are you saying that one reading bounced back and forth between 29 and 40 ohms? Yes

are you saying that you tested the female end a couple times and it read near 337 ohms every time? Yes

if the answer to my last question is yes, then this is the end that comes from the stator and the ignition portion of your stator coil is very good. Whew ya had me shakin ,,,,,

also, as a rule of thumb . . the end of a wire that supplies voltage to something will almost always have a female end . . its just the way they seem to do it. thank you

just exactly, in detail, is the problem with the bike?

Difficulty starting, when it runs it runs very strong then it wont idle right, I broke down the carb then it wouldnt start at all after installing,,,, so I sent my carb out to Flying W and he found there was a flat washer and o ring missing just got the carb back today and it looks brand new like right out of 1986.... also replaced the spark plug and replaced oem gas tank with a new clarke tank,,, replace fuel line and inline fuel filter,,,, trying to rule out all fuel issues. Lets see what happens when I install the carb.

[barnett468]

ok, please just answer these yes or no for me.

is you meter digital? Yes

are you saying that you tested the male end three different times and you got three different readings? Yes

are you saying that one reading bounced back and forth between 29 and 40 ohms? Yes

are you saying that you tested the female end a couple times and it read near 337 ohms every time? Yes

if the answer to my last question is yes, then this is the end that comes from the stator and the ignition portion of your stator coil is very good. Whew ya had me shakin ,,,,,

also, as a rule of thumb . . the end of a wire that supplies voltage to something will almost always have a female end . . its just the way they seem to do it. thank you

just exactly, in detail, is the problem with the bike?

Difficulty starting, when it runs it runs very strong then it wont idle right, I broke down the carb then it wouldnt start at all after installing,,,, so I sent my carb out to Flying W and he found there was a flat washer and o ring missing just got the carb back today and it looks brand new like right out of 1986.... also replaced the spark plug and replaced oem gas tank with a new clarke tank,,, replace fuel line and inline fuel filter,,,, trying to rule out all fuel issues. Lets see what happens when I install the carb.

lol, ok xlnt . . its just sometimes less confusing and faster to ask and answer questions thus way.

i would put the bike in the shade then lay the plug on the head with it connected to the coil wire when the engine is cold and kick it over and look at the spark . . if it is lite pale blue it is very good . . if it is yellow, it is about average to poor but most still run fine that way.

do this same test after it is hot . . if it was blue and still is, your electrical system is nit breaking down when hot . . if it was blue and is now yellow, it is a bad thing and one of your coils is weak . . if was yellow then it will still be yellow so this test spark color test wont help much, but you still may notice if the spark is weaker.

if it still idles erratic spray flammable brake cleaner with the long nozzle gently around the intake boot at the head and the carb . . if the rpm goes up, it has a leak.

if there is no air leak then try adjusting the fuel mix screw . . by turning it 1/4 turn in one direction then rev it up and let it idle again for a 30 - 45 seconds minutes . . if it is still erratic then turn it another 1/4 in the same direction and repeat test.

if it has no affect, or gets noticeably worse, return the screw to its previous position and rev it and let it idle for 30 - 45 seconds then turn the screw 1/4 turn in the opposite direction that you did for the first test and try that . . then turn it another 1/4.

leave it where it idles the most consistently.