Skip to content
Aussieveedubbers

New exhuast

0 likes
Share Share on Facebook Share on X Share on Reddit

milestones54 Slammed & Awesome Dubber

99 posts · joined Mar 2009 ·

#707335
Hi guys
Just fit my new "quiet" system to my 1600
Problem is im having backfiring every now and then and when i let off the accelerator in 3rd and fourth the car...splutters (id call it). Sounds like a weak backfire.
So far iv had mixed opinions as to whether this is bad or not.
Someone said increase carby jet size (as opposed to air fuel ratio) to eliminate this, if so what is a good size upgrade for a stock carby.
In another topic i said i was able to get a hold of twin dellorto 45mm's, would it be possible to use a single or are they still too big?
Thanks alot guys, im getting alot of help through the forum and the more people respond in the same way, the more sure a learner can be of whats right

Bizarre Moderator The artist formerly known as blue74l

12,789 posts · joined Aug 2002 ·

#707341
Are you 100% sure you dont have a leak??

The slip joint / clamp on the headers where they joint at 1 and 3 cylinders is usually rubbish

I reckon you are leaking there

As for carbs - 45's could work if you change the venturis to 32's
Singles are usually a real bitchto jet properlly
Futue te ipsum!!!

milestones54 Slammed & Awesome Dubber

99 posts · joined Mar 2009 ·

#707371
The headers run into the standar heater channels and as they didnt meet up i had them welded and "exhaust concreted"
It seems as though there is no leakage at all

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 ·

#707374
To check for exhaust leaks, when engine is cold and idling, block the exhaust outlet and you should hear any leaks until the engine stalls. Otherwise you must have a carby wear/tuning issue or an inlet manifold leak creating a lean condition.

Concreted exhaust sounds interesting😂😂
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

milestones54 Slammed & Awesome Dubber

99 posts · joined Mar 2009 ·

#707375
I might try that, one person said to me that the car might just need to be tuned for that exhaust (air/fuel etc)

Anthiron The Baja Rejuvenation Begins

4,936 posts · joined Oct 2003 ·

#707419
had similar problems one, check your exhaust gasgets, failing that it might be unrelated to the exhaust, check for manifold leaks, points, timing, if your timing is too retarded it will backfire, points with too small of a gap it will backfire, or you might be running lean on the carby.

tune your engine.
62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
2004 Harley Davidson Sportster XL Custom

Pete Officially Full-On Dubber

251 posts · joined Mar 2005 ·

#707518
Matty is right, block the tailpipe and listen for a chuff sound. Any backfiring from the exhaust is from a leak!, had many cases even from the smallest pinhole. Just make sure its not backfiring through the carby and your getting confused, it may cause u to bark up the wrong tree!!!!
pete - Custom Vee Dub
28 Hayward st stafford 33564356

Craig Torrens 6 times Australian, 7 times State Hillclimb Class Champion

8,040 posts · joined Jan 2003 ·

#707522
135 main jet for the stock carb