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Old 12-23-2015, 07:57 PM
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TopCatGr58 TopCatGr58 is offline
Join Date: Jul 2002
Location: Portsmouth, Va.
Posts: 12,620
Originally Posted by kflyboy View Post
If I switch plug wires 2 & 3 on the coils to narrow it down to #2 carb do I need to switch the wires from the harness that plug into the vf1000 could as well?
Hey there, Don't mind those two, they do get a bit grumpy every now and then!

Okay, each coil fires both wires at the same time for that respective coil, so that's why you can just switch the 2 and 3 plug wires/caps to opposite cylinders, and will fire correctly. This technique is to see if the problem is Electrical...the problem will follow the wire and # 3 will start having problems and misfiring. BUT if it's a CARB issue, then #2 will still be problematic, and the #3 will continue firing as usual.

Fuel in the carb throat/air box is signs that the carb is still flooding, which can fuel fowl your plug and cause the miss. You say you checked the needle/seat. Aside from a piece of crud getting stuck/wedged in between the needle/seat, the actual float can also just get HUNG UP/stuck for several reasons. Either corrosion on the float PIN so that it doesn't swivel properly/easily, or even a new thick/wide bowl gasket that catches the side of the float keeping it from moving.

Also, did you clean the carbs, and did you use a Carb Kit ie. K&L brand??
Their parts are known to cause problems/issues, the float needle is designed wrong and can allow the flaot not to seal properly vs. Original Mikuni parts.

IF the pick up coil wires were breaking, they usually cause a miss in 2 cylinders because they cause an entire coil to loose fire, not just 1 plug!

From what you've stated, my money is still on problems with the carb/floats more than the wires/coils....VF1000 coils are just fine!

There are other more rare conditions that can cause loss of spark on just 1 the resistor in the plug cap can go bad, or get too much corrosion on it causing it to not fire, or fire with very weak spark.

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