 Another Carb/Timing Question, I am really not good at this stuff |
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| tornik550 |
 Aug 24 2008, 05:55 PM
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#1
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Senior Member  Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None  |
I have recently gotten my 914 up and running after a rebuild. I have been trying to work on the carbs and timing. The car runs ok but I am shooting black soot out of the exhaust and the exhaust backfires on decel. Engine idles fine. I have been reading and searching for a long time. I have read too much and I am now super confused. I keep reading that the backfiring on decel is from a lean condition and the black soot is from mixture being too rich? I am confused, can anybody help me? To confuse me more, I recently saw some white/blue smoke- I checked my compression and I am getting 150 in all cylinders.
car info -73' 1.7 liter however I now have 96mm jugs, 78.5mm stroker crank- making engine displacement just under 2.4l. -the previous owner put in a new camshaft however I do not know the details other than that it is from webcam -2.0 heads -cromoly pushrods with clearance set to 0 cold -timing set at 27 degrees at 3000 rpm -bosch 050 dizzy with pertronix -msd 6al carb info (all the jet/venturi/etc sizes were placed by the previous owner) -dual weber 40 idf's -carbs just rebuilt last week -32 main venturi's -120 main jets -f7.5 emulsion tubes -200 air correction jets I am so confused. Your help is greatly appreciated, Steve |
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| r_towle |
Aug 26 2008, 08:16 AM
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Custom Member Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States 
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I guess after rebuilding three motors you are the Guru.
I wish you were into aircooled cars way back when I got my first one...you would have set me straight.... Never use an 009 an a type 4 motor. BTDT...its just not the right advance curve. The 050 is closer and works alot better. I stick with the stock 2.0 distributor and never have issues. Just dont run the vacuum advance, its not needed. the distributor is a big part of having a tunable motor... 3 people, myself included are repeating real world experience running dual webers. I had a stroked 2.4 with 98mm cylinders, its an old combo that was around back when Mahle made aluminum 98 mm cylinders for the type 4 motor....it was pretty common 15 or so years back. Works out to 2368 (circa 2.4) and ran on 40mm webers to meet SCCA rules at the time. Rich |
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Posts in this topic
tornik550 Another Carb/Timing Question Aug 24 2008, 05:55 PM
r_towle Well, you probably have two issues.
Backfiring ou... Aug 24 2008, 06:08 PM tornik550 I will look for the exhaust leak. Any good ideas ... Aug 24 2008, 06:33 PM SirAndy
I am so confused.
Like rich said, backfire throug... Aug 24 2008, 07:08 PM r_towle to find the leak put a 2*4 over the exhit tailpipe... Aug 24 2008, 07:12 PM tornik550 it appears that my idle jets are 50 Aug 24 2008, 07:48 PM r_towle I would say first fix the exhaust leak.
I had 40m... Aug 24 2008, 08:00 PM 904svo With the Weber 40's , I would suggest you chan... Aug 24 2008, 08:11 PM tornik550 where can you get 38mm vents for a 40idf? i just ... Aug 24 2008, 08:54 PM Joe Ricard 1st of all NEVER trust what the internet Yahoos sa... Aug 24 2008, 09:20 PM
roadster fan
1st of all NEVER trust what the internet Yahoos s... Aug 25 2008, 01:06 PM
r_towle
Now it really doesn't matter what is stamped ... Aug 25 2008, 02:32 PM r_towle Make sure you listen to Joe, he knows everything.
... Aug 24 2008, 09:33 PM Joe Ricard See at least Rich knows who's the "Mac Da... Aug 25 2008, 07:27 AM Joe Ricard What you still can't read?
You even re-posted... Aug 25 2008, 02:47 PM wertygrog
JETS size as in main jet size of 120 will not r... Aug 25 2008, 10:25 PM r_towle
JETS size as in main jet size of 120 will not ... Aug 25 2008, 10:28 PM r_towle I know you like picking a fight, but read what I w... Aug 25 2008, 03:34 PM Joe Ricard That would be one heck of a starter to spin a moto... Aug 25 2008, 09:16 PM SGB It has been a long time, but I thought (ouch) that... Aug 25 2008, 10:40 PM Joe Ricard Yea I have had a 2.0L engine for many years. Low ... Aug 26 2008, 06:20 AM |
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