4 isn't firing
schnowz at localnet.com
Tue Aug 5 18:12:43 PDT 2008
Sounds right - Easy enough to check. Put a clear piece of tubing on the bowl drain and form a U against the carb and open the drain. Level should be close to the joint IIRC (compare it to No 1)
----- Original Message -----
From: Dave Daniels
To: schnowz ; gpzlist at micapeak.com
Sent: Tuesday, August 05, 2008 8:41 PM
Subject: Re: 4 isn't firing
I tried switching the wires between 1 & 4, as well as switching the plugs. When I pulled no. 4 plug, it was wet. Also, I looked down the well and you could see the top of the piston was wet. After switching the wires and plugs, the problem remained at no. 4. So, I'm thinking Dave Beard is probably right in that maybe a piece of grip got in the carb and is holding the float open causing no. 4 carb to flood the cylinder while it's running. By the way, I haven't put a fuel filter on yet. Doh!
schnowz <schnowz at localnet.com> wrote:
That would also be the case (2 cylinders not firing) for the wire if it
was a bad connection eg green snot at the end of the wires where the copper
wire used to be, because the 1 and 4 are in series. The only way it would be
one cylinder, would be if it was a bad connection and also shorting to
ground somewhere (bad insulation etc). You can also ohm out the leads and
caps - the resistance is in the book IIRC. Though this will only test
resistance of the wire/caps and won't necessarily tell you if you are
getting high voltage leakage on the insulation. Only way to do that is swap
the wires with a known good one and the cool header should move with the bad
If it's doing it only at small throttle openings I would also suspect the
pilot circuit - carefully take out the pilot screw after putting a towel
over the engine. Make sure you get the o ring out too. Squirt some carb
cleaner in there and then follow with compressed air. You can get the screw
out by placing a short screwdriver bit in a socket and turn the socket with
your fingers (not a rachet - which is too big) Before taking it out screw
it in carefully and count the turns to bottom out - when reinstalling - turn
it to the same position as before.
By the way a infrared thermometer fired at the exhaust headers are great
for checkin which cylinders aren't firing.
> Start with coil, plug wire or faulty spark plug, although if it was the
> you'd probably see two cylinders not firing.
> Bill in Yardley, PA
> wkdenton at verizon.net
> ----- Original Message -----
> From: "Dave Daniels"
>> So, it seems no. 4 isn't firing. Any ideas?
>> Dave D.
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