Ignition failure

[Speyman]

Folks, two short rides after completing a spline lube, (great improvement by the way) my 1981 R65 soon required multiple crankings to start, then would die as I increased revs to warm engine off choke.  Yesterday, same symptoms but then after a two mile ride, it died completely and could not be restarted. Coil and ICU were replaced 1000 miles back. Would a damaged neutral switch cause these symptoms or is it more likely ICU or Hall trigger?   Electrickery!

[Bengt_Phorqs]

Speyman (you're not a veterinarian are you?) it's possible that the neutral switch is the culprit.  Did you also change spark plugs when you did the other electrical upgrades?  It almost sounds more like it's a fuel problem.  Next time it dies remove the float bowls and have a look.  No gas in the bowl means something is plugged up.  There is also a small orifice in one corner of the float bowl that can be easily plugged with crud.  Montemil has a photo of that problem somewhere on here.  Lots of good carb and electrical info on here, just run a search back for 12 months or so.

[Bob_Roller]

Welcome Speyman !!!

First, a neutral switch problem will not cause the problem you have, as long as the starter still works .

Have you checked the ignition system, by putting the spark plug on the cylinder fins, and then crank the starter .

Just a question on your replacement ignition parts, are they new, or are they used ?

There's a test for the Hall sensor in the 'bean can' .

Do a search for Hall Effect sensor test .

I think it entails putting a jumper wire across two pins on the electrical connector that goes on the 'bean can' , under the front cover of the engine .

[Speyman]

Not a veterinarian, just a fisherman! The carb bowls were full, floats seem fine. Spark plugs were not touched. R65 was running great (except for sticky clutch) before spline lube. The symptoms are similar to a year ago when I bought the cycle and found the crackmatic coils. I installed a new ICU at time as well and it has started on the button since then, even in the coldest weather.

[Bob_Roller]

Well, I guess you need to determine if it is a fuel problem, or an ignition issue .

[Speyman]

Thanks, Bob and others. Glad to know its not the neutral switch as it is a bear to get to. I do have a copy of the test procedure for the Hall Sensor and ICU. Will try those out tonight.

[Speyman]

Well, I pulled the spark plugs, grounded each to the cylinder head, turned on the ignition and flipped the kill switch from on to off and back a few times. No spark at either plug. I think this means the ICU is toast. I don't think I shorted it as I was careful to remove the battery ground before removing the tank and front cover. Perhaps just a coincidence but it seems that one should expect the life of an ICU to be more than one year!

[nhmaf]

Did you put a thin smear of thermal heatsink paste on the metal back of the ICU before bolting it back onto its aluminum backing plate (heatsink)?   If not, the ICU may not effectively conduct heat through the non-perfectly mating surfaces and overheat.

[Bob_Roller]

Did you perform the test that has you remove the connector from the 'bean can' and jumper the wires there ?

That takes the Hall Effect sensor out of the system .

If you don't get a spark with this test, the Hall sensor is still  probably good, then you can be sure the ICU is at fault .

Did you apply any heat sink paste on the ICU, that's if you have an ICU, that the heat sink is removable from the ICU itself ?

Some later production ICU's, have the ICU and heat sink as an assembly, can't separate them without damaging them beyond repair .

[Speyman]

Thanks for the advice. I have not yet tried bypassing the Hall sensor test, but will tonight. I also spoke to Rick at Motorad Elecktric from who I bought the new coil and ICU 12 months ago. He said the ICUs hardly ever fail but he is seeing lots of intermittent problems from poor electrical connections in the plugs. I did apply the proper heat sink past when the ICU was new and it still looks fresh, not hardened. I understand an intermittent Hall trigger may be very hard to isolate.

[Speyman]

Found the culprit! I replaced the coil as the primary resistance was low; still no spark. I then cleaned and lubed all the terminals and connectors on the ignition switch. Still no spark. So, I got out the trusty volt/ohm meter and begin tracking down the continuity. Sure enough, no current was flowing through the "kill" switch, even though it had been cleaned about 4 months previously. I disassembled it, re-cleaned, stretched the tiny spring a little, buttoned it up, and she fired immediately. This tiny switch kept me stationary for six weeks!

[montmil]

Found the culprit!... no current was flowing through the "kill" switch, even though it had been cleaned about 4 months previously. I disassembled it, re-cleaned, stretched the tiny spring a little, buttoned it up, and she fired immediately. This tiny switch kept me stationary for six weeks!

Fortunately, most problems on our "tractors" are ultimately tracked down and judged as "simple".

Sorry you lost six weeks -I could not be that patient- but the fix was free! Can't beat that.

Monte

[Bob_Roller]

Good to hear you got it fixed .

As is common with most electrical problems most of the work, is in finding the problem, the fix can be a matter of a few minutes .

Not ever having taken the kill switch apart, any warnings or cautions to be aware of ?

What replacement coil did you install on the bike ?

[Speyman]

The kill switch is pretty fragile. The is a tiny E-clip about 2 mm in diameter that is easily lost plus a tiny spring that fits on the switch shaft. A small flat brass disc about 1 cm in diameter with three raised bumps makes all the connections. The disc can be placed four ways on the switch shaft; three of which are wrong!

I installed a single brown coil from Motorrad Electrik. Rick Jones is a great resource.  If I recall correctly the old coil read .3 ohm resistance on the primary side and the specs are .7 to 1.5 ohm.

[Bob_Roller]

It pretty much sounds like the turn directional/headlight switch, probably in your best interests to replace it, as you most likely will break something try to repair it .