dropped a cyl

[ScottsXS]

i rode to work today everything went fine there on way home started popping and running ruff. pulled over started narrowing things down.......cyl 1 spark/fuel,cyl 2 spark/fuel,cyl 3 spark/fuel, cyl 4 no spark/must be getting fuel as it is dumping fuel into the exhaust to cause popping. shes got new pluggs new wires and new mikes xs coils. WTF!?!?! any body got ideas????

[prometheus578]

Get some clean plugs and retest.
I can imagine that the plug for #4 is fouled. Might not spark no matter what you do.
Now then.. with all new plugs.. check for spark again.
Coils work in pairs, as you know. #1 get's it's spark at the same time as does #4. For only one plug to get spark and not the other, you've either got a defective wire to that plug, a bad plug cap or a fouled spark plug.
If the new plug fires for a while and then fouls... well, we've got other problems now and they're not spark related.

[fredintoon]

Hi Scott,
Mr Stupid fought with his iggy an entire week to no avail trying to get #4 working again. Cleaning #4 carburettor fixed it right up inside of an hour.

[ScottsXS]

im not getting any spark through #4 wire to any ground, have to pull the tankand check where the wire connects to the coil

[TopCatGr58]

Hey Scott,

Along with checking the wires for that coil, also check and verify that the coil is getting it's full 12 volts during starting cycle.

Had a fellow Xsive with weak fire on 2 of the 4 plugs he had, 1 from each coil....which didn't follow the normal linked pairing of coils/pu coils and such!!

Turned out that the power lead to the ig. coil was corroded at the connector, and not providing the full power, so the resultant spark power from the coil was enough to jump thru the main spark plug on that coil...but once it travelled thru the engine and back up to the paired plug there wasn't enough juice to allow it to jump the gap properly to return back to the ig. coil!!

But hopefully it's just a corroded resistor in the cap!
T.C.