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Old 04-09-2008, 12:00 AM   #8 (permalink)
RSA350
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Join Date: Sep 2008
Location: West Oz
Ride: '69 HT Monaro, '74 CJ5 Jeep, '85 CJ10 Jeep
Posts: 20
Default Backfire

Hi guys,

I understand that a single point dizzy will be no good for high rpm. It pulled 7000 back in the commo with the twin point lol, the engine is in a 4x4 now and could really use a torquier cam. I converted the current dizzy with to an optical pickup with a crane xr700 conversion kit. In an effort to find the cause of carb backfire I threw points back in, ill get around to re-instating the xr700 shortly.

As for the back fire, when free revving the engine I hold the revs up at about 1000 to 1500 then crack the throttle wide open, CHOOF, back fire, from what I can tell there is no flame (riding valve on compression stroke?) the revs then pick up.

When driving it constantly back-fires during acceleration under load, once the revs get up it seems to be ok. I can sometimes avoid the backfiring by gently feathering the throttle up to speed.

Point to note, i did put a new power valve in the holley a while back....

Your thoughts?

-Ads
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