Backfire - when I turn off the engine ? |
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Backfire - when I turn off the engine ? |
kenpolives |
Jul 21 2007, 07:28 PM
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#1
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Member Group: Members Posts: 167 Joined: 31-December 03 From: Albany NY Member No.: 1,479 |
I got the car back from the mechanic yesterday, he replaced the first gear syncro and did some welding on my heat exhanger. I was getting a backfire when I shut done and a little decel popping from the leak. He also said he adjusted my carbs (44 webers on a big bore 1.7)
Now I don't get the popping sound but I get a giant backfire a few seconds after I turn of the key/engine. Advice? |
kenpolives |
Jul 22 2007, 06:04 AM
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#2
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Member Group: Members Posts: 167 Joined: 31-December 03 From: Albany NY Member No.: 1,479 |
I got the car back from the mechanic yesterday, he replaced the first gear syncro and did some welding on my heat exhanger. I was getting a backfire when I shut done and a little decel popping from the leak. He also said he adjusted my carbs (44 webers on a big bore 1.7) Now I don't get the popping sound but I get a giant backfire a few seconds after I turn of the key/engine. Advice? So, is this a carb issue - too rich? an exhaust leak, or am I just screwed. |
jonferns |
Jul 22 2007, 07:05 AM
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#3
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Advanced Member Group: Members Posts: 2,081 Joined: 29-March 07 From: New Jersey Member No.: 7,631 Region Association: North East States |
bump
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BarberDave |
Jul 22 2007, 07:48 AM
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#4
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Barberdave Group: Members Posts: 1,605 Joined: 12-January 03 From: Wauseon Ohio Member No.: 135 Region Association: Upper MidWest |
(IMG:style_emoticons/default/smilie_pokal.gif)
Ken: IMO if you have a stock 1.7 ,( bore ,stroke,& cam) you are way over carbed. Most guy's that use 44's have at least 2.0 or bigger. I have a 1.7 also i have Weber 40's with no problems. I think you are to rich,when you shut it off there is a still a load of fuel in the intake side of the engine and it gets lit off. Resulting in that back fire ,. Now why is does that will be up to someone who knows 44's much better than I . I would start by astablishingif the tune of you engine is correct and dead on. Also pull the plugs and see if they are wet,or black, if the back fire only occures when you shut it off that sugests ,to me ,idle jets may be to big. They are very easy to pull,( if the same as the 40's) and check size . then post . We will get this streighten out . Dave (IMG:style_emoticons/default/slap.gif) P.S. I was assuning the back fire is comming out the carbs???? for it to be intake issue. In rereading your post it seems to be on the exhaust side ,if so that says way to rich on the main jets and idle side .post the sizes you are running and the venturie size,we will get ironed out. |
Coy |
Jul 22 2007, 05:09 PM
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#5
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Member Group: Members Posts: 352 Joined: 6-February 06 From: Salem, OR Member No.: 5,537 |
You know... I'm kind of paranoid once in a while, but I would be very leery of a carb back fire when you shut down. A carb backfire can light your air filter on fire (and then the rest of your car).
On old motorcycles any way; if your carb backfires the best way to put it out is to kick the engine through; that will suck the flames into the engine & extinguish the fire. An exhaust detonation is generally louder and more annoying and embarrassing, but not threatening. I'm certainly no expert, but IMHO; your exhaust can handle unbrunt fuel, your carbs cannot. |
SGB |
Jul 22 2007, 08:42 PM
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#6
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just visiting Group: Members Posts: 4,086 Joined: 8-March 03 From: Huntsville, AL Member No.: 404 Region Association: South East States |
Did he use new crush gaskets when he put the muffler back on?
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