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1973 340 olympique backfiring and bogging

7
Oct 17, 2016
3
0
1
Near edmonton
Hi im new to forums and sled mechanics so i rebuilt my 1973 340 olympique a short time ago after finding out one cylinder had zero compression so i got it done and it ran great for a little while lots of power and rpm's but now it idles fine but after that it just backfires and boggs alot and no power, theres no electric leaks visible in the dark so now i just dont know what to do thanks for any advice :face-icon-small-dis. I just rechecked the compression since after the rebuild and its now way down at 94 psi a side
 
Last edited:

joshkoltes

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Dec 16, 2007
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when you say a little while do you mean a little while last year? if yes then re clean your carbs. if you mean a little while a week ago start at the tank make sure its clean with fresh fuel. sure the line in the tank hasn't rotted off and the brass screen is still on the end of the hose, buy a pump rebuild kit, check the vacuum line from the pump to the case- actually just replace the line they often get weather checked.

if you found debris in the tank re clean the carbs
 
7
Oct 17, 2016
3
0
1
Near edmonton
I rebuilt it last winter and it sat outside with a tarp over it and i also just noticed it spits alot of gas from the carburator, It has lots of vaccum and rebuilt the carburator last year
 

Ox

Snowest's Axe Murderer
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Jul 8, 2001
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www.midwestproductionmachining.com
I just rechecked the compression since after the rebuild and its now way down at 94 psi a side


... and it runs?


What PSI did you have when it ran right?


I'd be lookin' for the missing PSI!

I had a '72 Olympic, but then it was a 335 single lung.


.
 
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