Ignition Coils

[AppleJack]

Hello All
Attempting to revive a long asleep 1985 FJ1100.  Coils appear to be bad as primary side of both check at 13 ohms with my Fluke DMM.  If I read my Clymer manual correctly this should be 2.4-3 ohms?  Secondaries 27 meg ohms.  These are toast, right?

Are replacements available?  I don't see them on rpmracingca.com  Any other options for this problem? 

Thanks in advance...

[Pat Conlon]

That's surprising, other than some occasional cracks, the FJ's oem coils have shown to be very durable.
If your testing shows both coils to be bad, I would suspect your test methods.
The probability that both coils went bad at the same time is low.
Others will chime in on your test numbers, I'm away from home now.

Re: Alternate Coils:
Dyna green 3.0 ohm coils are a popular substitute for oem.
You have to buy plug wires and boots separately with the Dyna coils
2 options on the plug wires/boots.
1) buy carbon core suppression wire and use regular non resistor plug boots
2) buy regular steel (copper) core non suppression wire and use NGK resistor plug boots..
https://www.ebay.com/p/Dynatek-DC1-1-Coil-12v-3-0-Ohm-Green/171268638

Check FleaBay for oem coils, they come with steel core wires and resistor plug boots.

Cheers

[roverfj1200]

Not to sure on which Fluke you have I would say there are 2 reasons maybe your readings are out. 1 The impedance and 2 bad leads..

That is to say you are testing insulation for a higher voltage.  A cheap multi meter with out these better testing functions can be better for this type of testing.

[racerrad8]

Did you remove the spark plug boot to test the secondary?

Randy - RPM

[krusty]

Hello All
Attempting to revive a long asleep 1985 FJ1100.  Coils appear to be bad as primary side of both check at 13 ohms with my Fluke DMM.  If I read my Clymer manual correctly this should be 2.4-3 ohms?  Secondaries 27 meg ohms.  These are toast, right?

Are replacements available?  I don't see them on rpmracingca.com  Any other options for this problem? 

Thanks in advance...

I would first check ALL connections in the ignition circuits. Corrosion and poor earthing can affect readings.

[ribbert]

Hello All
Attempting to revive a long asleep 1985 FJ1100.  Coils appear to be bad as primary side of both check at 13 ohms with my Fluke DMM......

Going back one step, have you checked for spark and there is none, or have you just dived straight into the coils because it won't start?

If it was ridden to its resting place, the coils will be fine, they don't deteriorate by time.

If there is no spark, follow Krusty's advice first.

For bikes that have sat for a long time, it's nearly always carbies.

Noel

[AppleJack]

Right, my Fluke 8060A is similar vintage as the bike, if not a couple of years older!  I'm troubleshooting no-spark condition - plug laying on to of cylinder head and nothing.  Agree more testing called for and will be re-doing ground connections and rechecking all other connections, too.

Had some 1/4 watt, 5% resistors lying around so did some checking: 
Five 220 ohm resistors averaged 215.88 - 4.1 ohms and 1.8 % low. 
Five 330 ohm average of 322.4 ohms - 7.76 ohms and 2.3% low. 
Two 1,000 ohm average of 994.9 - 5.1 ohms and 0.5% low.              All resistors within 5% tolerance though.

Duplex receptacle in kitchen measured 117 volts AC. 

I conclude from this that, if anything, the 13 ohm reading is a little low?  Meaning the primaries are even farther out of spec, right?

[AppleJack]

Huh - Went out and re-checked coils with my ohmmeter.  And this time readings are normal for both primaries and secondaries.  Only difference I applied some dielectric grease to all connectors. 

Moving on.  I have a question about the small springs under the resistor in the spark plug boots.  Two are missing - is this critical to the plugs firing?  Are they available? 

Also, I have a schematic that shows a rev limiter - where is it physically located on the bike?  Schematic is for 1100L / LC  Mine is a 1100N.

[Pat Conlon]

Time for new boots: http://rpmracingca.com/proddetail.asp?prod=Ignition%3ANGKBoot

Re: Rev limiter: I don't know what schematic you're looking at. Some FJ models were power limited to 100bhp like FJ's sold in Japan, Switzerland and France and thus had certain limits in the carbs (jetting, boots, airbox) and ignition (timing curve, lower rpm limit)

You should have a USA FJ with no power limits, but there is a high RPM limit (~10k rpm?) programmed into your TCI. IOW there is no separate RPM limiting module, it's part of your TCI.
(TCI = Transistor Controlled Ignition aka your ignition box)

Clear as mud?

[AppleJack]

Yep, and just glad new boots are still available. 

The schematic says it's for a a 1100L / LC and mine is a 1100N.  I suppose the N is USA model? At any rate, no separate module near the IC/Ignitor box anyway.  I think you're correct that it's internal to the TCI. 

Oh, and are the rubber grommets that hold side fairings on available anywhere? Several are MIA.

One other dumb question - use same DOT 3 fluid in clutch, front brake, and rear brake reservoirs? 

Thanks...

[FJmonkey]

Jon, you will find a ton of FJ parts at the RPM web site, including the rubber bits for the fairing. Randy is also a Yamaha dealer so not just FJ. And the OEM brake/clutch fluid is DOT3. Some have flushed out to use DOT5 like I did for the clutch. So when the slave leaks, and I don't catch it, the fluid won't hurt the lower fairing anymore than it already is.

[ryanschoebel]

but there is a high RPM limit (~10k rpm?) programmed into your TCI. IOW there is no separate RPM limiting module, it's part of your TCI.
(TCI = Transistor Controlled Ignition aka your ignition box)

Can anyone elaborate on how that works? I may have accidentally hit that before, and want to know how concerned I should be. Dont ever really want to hit it again... Nothing like thinking you are in second when you are in first...

[Tuned forks]

As Monkey elaborated, the RPM site is your friend. 

Here are two examples.
https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3A90480-01401

and
https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3A90480-13014

Joe

[AppleJack]

All you are the best!  Thanks for the heads up on parts.

In making my parts list, I remembered that the mirrors are in really tough shape too.  Can just the mirror/glass be pried out and replaced?

Or is there anything that screws directly into the existing mount that will work? 

Evil bay has some universal mirrors, but would need to know the thread size before going with something like that I think?

[Pat Conlon]

Re: 84/85 handlebar mounted mirrors.

Many aftermarket options available, however, be advised that the right mirror is a reverse thread.
This is something all Yamaha's have in common. This reverse thread prevents overtightening of the mirror stalk on the right side from wind pressure pushing on the forward side of the mirror.