how do u test a coil on a bike, 4 stoke engine suki 1100 83model?

Question

my bike wont start , i try new battery,new plugs oil gas etc etc ,im thinking it the coil,used to run,but wont fire at all trys to trun over some

Answer 1

Those things have an electronic CDI.

You could have coils that would Arc Weld,,,,
if CDI amp or triggers aint working it doesn't do any good to crank it and look for a spark,,huh?
Pull gas tank off so you can get to the coils.
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Live Fire Test,,
gives visible confirmation of function

Unplug "hot" wire at coil
---Only 2 wires besides the spark plug cable,,one's Ground,,one's "hot"

Get a wire connected to any verified +12v source,,,
and poke it at Coil's Primary lead(the hot wire)
DO NOT leave it connected any time,,,just contact>release.

It wont spark till you "break" the circuit.

If the coil sparks a plug,,,it's OK

Odds are slim that a coil is bad.

Probly the "box",,Igniter/CDI Unit,,,whatever they call it.

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You can use an ohmeter to test the coil
--on Rx1 scale,,measure resistance between the 2 primary wires.
***You NEED factory specs to compare,,,but should be between 1 & 2 Ohms on most coils

--on Rx1000,,measure between Primary + and Plug wire.
***You NEED factory specs to compare,,,but should be between
7~8K and 20K??

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Check the pickup coils with Ohmeter---***You NEED factory specs to compare

Check their output on a millivolt scale---***You NEED factory specs to compare,,,but should fluctuate when cranked

Check primary voltage to Main Coil

Check 12V+ Supply to CDI box

Sometimes Ign Switches are built with separate contacts for Ign/Lighting/Cranking.
Yours,,I just dont know??
But the symptoms can be power to Crank,,but none to ignition.

Same for handlebar kill switch----in RUN position it's gotta MAKE contact.
Bad Contacts in there can leave Ign circuit "off"--disconnected.

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If 1 Coil Fires,,but other one doesn't,,,,swap the power wire at the coil.
--If the Dead Coil then Fires,,,both coils are probly OK

--if the previously firing coil quits when the primary wires are swapped......
Then that side of the CDI Box aint working

Swap the wires back correctly so ya dont forget to later

Then go swap the connectors from the triggers-to-CDI Box

If it makes no difference to the Coil's Firing---
then BOTH the triggers/pickups are OK.
And one channel in the CDI Box is bad.
Because EITHER pickup works on "Good 1/2" of the Box,,
while NEITHER P/U works thru "Bad 1/2" of the box.

If Swapping the Triggers at the CDI Box REVERSES which Coil fires & which dont....
Then the BOX is OK and one trigger/PickUp coil is bad.
Because----Good P/U will fire thru either channel on the box & makes it's corresponding Coil fire it's plugs.
But Bad P/U wont fire either side
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If all 4 plugs are Dead,,Probably The Box.
VERIFY 12v supply voltage 1st before condemning it.

Odds are VERY slim Both Secondary Coils would fail at same time.
And just as slim that BOTH pickup coils would fail together .

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Safety----
If you use a Jumper Wire to test fire coils directly from Battery.
*Connect wire securely to Battery,,,and use a short,,expendable "contact" in the Coils Connector.

a)Ya DO NOT want to strike any arc at the BAT terminals
b) Your Test Make&Break Contact to trigger the Coil is a Hot Arc and will burn the Coil's Connector----so beat up on a nail or piece of scrap wire stuck in the connector instead of burning the connctor itself.

---Do NOT apply any power to Pickup Coils,,,
--Do NOT apply any power to CDI Box's P/U Inputs
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I'd start by verifying 12v+ to the CDI Box....if it's there,,you eliminate all the possibilities of wiring harness & switch problems.

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Really a simple circuit.

It's like 2 separate Ignition Systems,,but with BOTH their CDI Amps in same box.

(TRIGGER #1 & #2) --->(CDI Box which has #1 & #2 Channel)-----> (Ignition Coils #1 & #2)

Only thing besides those 3 basic component groups is the 12V+ supply to the CDI Box---keep in mind it is Switched at several points ,,,as well as having plug-in connectors on the harness .
Those type things can stopi it just as dead as a bad part.

Just some ideas,,,

Hope any of it helps.

Those ol' 1100's are really good bikes,,it needs to get going again.:)

Happy Holidays

Answer 2

--That bike has 2 coils.
--The left coil fires the 1&4 spark plugs and the right fires the 2&3.
--Spark plugs are numbered 1-4 from left to right.
--It's highly unlikely that both coils would go bad at the same time.
--Put a known working spark plug (new is prefreable) in the #1 spark plug cap.
--Lay the threads of the spark plug on the engine.
--Turn on the key, kill switch to run and crank the engine (push the starter button LOL).
--Then check for spark at the #2 spark plug cap in the same fasion.
--If there is no spark anywhere, then the CDI, pulse generator, kill switch or wiring of the ignition system is bad and will need further testing. Buy a shop manual.
http://www.motocom.com/motorcycles/
--If you get spark at one spark plug but not the other, here's a way to check everything except the coils to rule out that part of the ignition system. The thin wires going to the coils, put the wires from the left coil on the right coil and the wires from the right coil on the left coil. Then check for spark at the #1&2 spark plugs again.
--If there "is" spark at the working spark plug from the first test, then both coils are good and the problem is else where.
--If there is "no" spark at the working spark plug from the first test, then that coil is bad and needs further testing.
--That's why you should own a shop manual. The manual will show you how to test and repair anything on your bike. The first thing anyone should buy if planning on working on their own bike, should be a shop manual.

Answer 3

Because of the soot in diesel motors the oil has a lot of detergent additives to keep this from clogging things up. In a used petrol car engine this will lift any deposits of the internals and hopefully drop them in the filter. A m/c engine generally only has a strainer so the rubbish will circulate until the oil change and that may not be good on a long term basis. On the other hand any oil is better than low oil, and the diesel variety may make a worn engine quieter as the thickness is greater. I ran a Norton ES2 with EP90 gear oil for a few miles once as I had no other available after a major leak had emptied it. No problems later.

Answer 4

Take some new spark plugs put them in the spark plug boots preferably next to the head make sure the plug is touching the head you should see a little blue spark jump the gap. If you don't then you need a new coil/coils. Check your plug wires for damage make sure the inner core isn't exposed this will cause grounding.

Answer 5

<>To just find out if the coil is putting out, remove the spark plug wire, hold the terminal end near the engine block (1/4") and crank the engine. If it's working you see (and likely feel! :) a spark arc between the wire and the block. To check the actual output of the coil, it will need to be bench-tested at a shop. But, if you have spark, that is probably NOT your problem.

Answer 6

If you have an old spark plug, pull one plug wire and hook it to the old plug. Set the old plug against the metal part of the engine ( a ground). Clamp it if you can. Crank it over, if there is no spark, it could be your coil or your points. Have you looked at your points? Maybe they aren't opening and closing.

Answer 7

If its not putting out a spark and you still want to know if its good or not, take an ohm meter and place it between the two end it should read about 2000-3000 ohms.