1986 FZ600 Loss Of Power, Won't Go Anywhere!

[StandAloneShell]

Hey guys, hope someone else has had this headache before so I can learn. My 86 FZ600 is difficult to keep running -

1: It either idles around 3,000 rpm or if I turn the idle screw down it'll drop down to 1,000 but die shortly after.

2: The bike will continue running if I remove either or both spark plugs on the outside of the engine (1 and 4) but will die when either of the plugs on the inside (2 or 3) is removed.

3: Subsequently the bike will not start if plug #2 or #3 is unplugged; however it will start if only #1 and/or #4 are unplugged.

4: On the road - the bike will die if let to idle more than a few seconds (stop signs are a real pain with this problem), and when the clutch is let out, even with the throttle wide open, it is sluggish to even get going. It will also not accelerate at all.

I am thinking it is an ignition coil; however I am inexperienced with this specific bike. Are there two coils on this model, each connecting to a pair of spark plugs? [Would explain the symptoms I'm experiencing] ANY HELP would be appreciated, thanks.

[Airhead]

Hey guys, hope someone else has had this headache before so I can learn. My 86 FZ600 is difficult to keep running -

1: It either idles around 3,000 rpm or if I turn the idle screw down it'll drop down to 1,000 but die shortly after.

2: The bike will continue running if I remove either or both spark plugs on the outside of the engine (1 and 4) but will die when either of the plugs on the inside (2 or 3) is removed.

3: Subsequently the bike will not start if plug #2 or #3 is unplugged; however it will start if only #1 and/or #4 are unplugged.

4: On the road - the bike will die if let to idle more than a few seconds (stop signs are a real pain with this problem), and when the clutch is let out, even with the throttle wide open, it is sluggish to even get going. It will also not accelerate at all.

I am thinking it is an ignition coil; however I am inexperienced with this specific bike. Are there two coils on this model, each connecting to a pair of spark plugs? [Would explain the symptoms I'm experiencing] ANY HELP would be appreciated, thanks.

If im right in thinking its a 4 cylinder, pinpoint the problem cylinders thus: -

From stone cold, start the engine and feel all the exhaust header pipes, the ones that stay cold are the problem...Take it from there.

You say it will run with the outside plugs removed, you should not do this unless the plugs are in the HT caps and they are grounded, it can damage your electronic ignition, just something i once read...no personal experience of this

[Paul Mc]

Most likely coil related, as per your examinations (as it sounds like it's only running on 2).

Not necessarily the coil, possibly something simple like the connector at the back of the coil for #1 and #4 - two small connectors, check that they are in position correctly, if yes take them off and clean the contacts properly and try again.

Most likely a problem with the earth (as the lives share a common feed for both coils).

Live will be constant, the earth will be switched via the CDi box based on a signal from the pick-ups, generating a spark via the plug in the process...

But possibly the coil - if you have a multimeter, there should be resistance values in the haynes manual for checking the coil.

Where are you?

Paul

[grizzlydan]

Hey guys, hope someone else has had this headache before so I can learn. My 86 FZ600 is difficult to keep running -

1: It either idles around 3,000 rpm or if I turn the idle screw down it'll drop down to 1,000 but die shortly after.

2: The bike will continue running if I remove either or both spark plugs on the outside of the engine (1 and 4) but will die when either of the plugs on the inside (2 or 3) is removed.

3: Subsequently the bike will not start if plug #2 or #3 is unplugged; however it will start if only #1 and/or #4 are unplugged.

4: On the road - the bike will die if let to idle more than a few seconds (stop signs are a real pain with this problem), and when the clutch is let out, even with the throttle wide open, it is sluggish to even get going. It will also not accelerate at all.

I am thinking it is an ignition coil; however I am inexperienced with this specific bike. Are there two coils on this model, each connecting to a pair of spark plugs? [Would explain the symptoms I'm experiencing] ANY HELP would be appreciated, thanks.

You'll find that 1 & 4 are on the same coil so check all the connectors to that coil, then check the sparks with plug caps removed (sparks should be nice & blue). If the sparks are ok replace caps & plugs. If not then check the coil resistence in the ohms range, primary coil (between the 2 power in connections) 2.43 to 2.97 ohms & secondary coil (between the 2 HT leads) 1.8 to 2.2 ohms. If the readings are outside these ohms then you know that coil needs replacing.