470 start issues

2fishy4u

Petty Officer 3rd Class
Joined
Aug 3, 2015
Messages
85
Hi guys, I paid a local mobile mechanic to install a new long block. He final had everything ready for a test start. It will not fire. The only resemblance to firing is a muffled backfire out the rear. He is stumped. I checked for spark, plenty of spark. Plenty of fuel. But will not fire. Anyone got any ideas where to look. Like I said it does a muffled backfire instead of firing.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
sounds like the dist was put in the wrong spot. go back to basics,.
#1 at TDC compression, drop in dist with the rotor aligned to a cap contact, firing order 1,3,4,2 cylinders are front to back 1,2,3,4
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
The timing marks will line up on either #1 or #4. So you will need to psychically check for #1 building pressure to get the right one.
 

2fishy4u

Petty Officer 3rd Class
Joined
Aug 3, 2015
Messages
85
Thanks guys, that was my thoughts. He just swears he did it right. Heading out there now to check myself
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Back in the last century I was replacing spark plug wires on a 4 cylinder, and got all dyslexic when I had momentarily held the cap upside down and got the wires 180 off on the cap. Like has been mentioned, basically start over and check everything related to timing set. If it ends up being ok on distributor and wires orientation then could be cam timing is off. A basic compression check would show if that is a problem or not.
 

2fishy4u

Petty Officer 3rd Class
Joined
Aug 3, 2015
Messages
85
Thanks for the help guys, he was counting the mark on the flywheel as TDC............ he was on cylinder #3 TDC. Used a compression gauge and got it on #1 then dropped it back in. Set the cables right, and she fired up.
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Good deal :thumb:

They work on a lot of different engines and that one is a little different than mainstream, and that can catch them offguard sometimes..​Glad you had a good mechanic that backed up their work.
 
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