Does anyone know the cranking voltage of the pulse generator and the exciter coil?

 

The manual only shows ohms values for those, that's all I have.

These are for the Fourtrax, not the Foreman which has no exciter:

Exciter - Black/Red and Green/White - 50-200 ohms
Pulse Generator - Blue/Yellow and Green/White - 300-360 ohms

 

I have the values for the resistance. My problems is that resistance checks oks so I replaced the CDI. Still no spark, so I would like to know the cranking voltage of at least the pulse generator. According to service manual there is a exciter coil page 21-1.

 

Right, the Fourtrax has the exciter, Foreman doesn't. Was just making it clear in case someone else uses the info.

Have you checked the neutral switch and the kill switch?

On my Foreman, the neutral switch is bad and killing the spark. I can ground the wire and get spark.

My kill switch had also been rigged, run is off, and off is run. Another poster just found his kill sw. was fouled up.

I would say if the parts ohm out correctly, those are ok and the problem is wiring or some other switch/part. I assume you tested the ignition coil? And the CDI is the correct part number for Fourtrax? 86-87-88 years are also different.

 

Yes , I have checked all inputs ans output. Checked and tested ignition coil and spark plug
wire and cap. Again the only thing in question is voltage on that coil. If it is in limits then my new CDI in no good.

 

Have you done the bypass test on the Fuel Cut relay, section 20-7? I have read that can also kill the spark, as it is tied to the CDI via the Blue/Yellow wire, on 86 Fourtrax.

If the tests in 17-3 to 17-4 (factory manual), all switches/relay and continuity in the harness, are all good, then the CDI must be defective.

The voltages must not be relevant, or they should be listed in the factory service manual. Always a chance someone has recorded those on a working system, but Honda doesn't appear to think it was needed for testing. Looks like they expect to eliminate everything else, then replace the CDI.

 

Hi Collar Bones, it is the black and yellow that are tied into the CDI via ignition coil. Voltage is relevant due to trigger voltage for the scr located in the cdi unit. If for instance lets say for some reason the gen coil as come loose and not getting a strong enough magnetic flux hitting the gen coil. I would like to know what voltage it takes to fire scr in CDI.

 

Ok, we are talking about two different components, but I did make a mistake, the Fuel Cut is tied to the CDI with a black/yellow, instead of blue/yellow as I posted. Apologies, it was late and the diagram is hard to read on the .pdf manual. So the black/yellow runs to the Fuel Cut, CDI, and the ignition coil.

Was suggesting the Fuel Cut bypass as a way to see if it will produce spark. In my search to troubleshoot no spark on my Foreman, I found posts that say the Fuel Cut can shut down the CDi. Eventually I found a bad neutral switch was the problem. I'm eliminating the Fuel Cut to avoid future problems out on the trail.

Keep watching, maybe someone does have those voltage numbers. I'll definitely be recording them if they are posted.

 

Thank you for your help. The fuel pump wire could stop spark if the black and yellow shorted to ground.

 

The info I saw stated the "Fuel Cut Relay" is to shut the bike down in case of a rollover. The relay can stick, keeping fuel and spark shut down even after the machine is upright.

Important enough that the bypass test is in the manual. Mine will be permanently bypassed.

I think if the black/yellow to the fuel pump is shorted to ground, the fuel pump fuse would blow. I did find my fuel pump fuse blown, though I'm not sure why yet. This one arrived with many problems and info from the previous owner that didn't make a lot of sense.