[Roadsters] Baffled by Backfire

[robert k. smith]

hi dave, a backfire, typically, is a lean fuel condition. but i have

seen a bad condenser cause backfiring (if you have elect. ign.,

disregard the last).also, ck. float levels, and ck. the metal fittings

where the little hose connects the float chamber to the movable

jet. ive seen a build up that partially blocks one or the other fitting.

 good luck, bob smith

                69 srl 311

> Date: Tue, 1 Jun 2010 18:07:13 -0500
> From: cookefam314 at gmail.com
> To: datsun-roadsters at autox.team.net
> Subject: [Roadsters] Baffled by Backfire
>
> During a recent road trip, I picked up an intermittent backfire thru the
> carbs. I found a bad plug wire & fouled distributor cap on my East Coast
> Dizzy, Dave Brisco sent out replacement parts for them both. I installed
the
> cap & new wires today. Timing is still at 16 degrees BTDC, I cleaned the
> carbs, checked the dashpot oil & rest the fuel mixture. Balanced the carbs
> wiith a unisyn. And, I'm still getting a backfire thru both carbs. It's
> still a bit intermittent, mainly happens on deceleration up to a stop, and
> then again on acceleration after a stop. Doesn't seen to happen at all at
> high speeds.
>
> Could this be something else like a vacuum or exhaust leak? The exhaust
note
> on acceleration sounds different to me now than before this all happened...
>
> Any help would be appreciated.
>
> --
> Dave Cooke
> Roadster owner since '83
> Lake in the Hills, IL
> Chicagoland Chapter of the Dairyland Datsuns
> ________________________________________


_________________________________________________________________
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with
Hotmail.
http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=PID283
26::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5