1970 Chevy C50 backfires

Swantongail · New User Joined: 18 Oct 2009 Posts: 2 Report to Moderator

Have a 1970 C50 grain truck that started backfiring something terrible. Checked the timing and the obvious. Any suggestions

noncompos · Posted: Sun Oct 18, 2009 8:40 am Post subject: Re: 1970 Chevy C50 backfires

A little more detail might help, like:
"Backfiring" thru the exhaust?? (out the tailpipe, likely to blow a hole in the muffler) OR:
Back up thru the carb, thru the air cleaner (aka "coughing" thru the carb)
Sorry to sound picky; local usage in different places sometimes confuses the two.
When, under what engine conditions( warm? accelerating? decelerating? steady driving?).
"The obvious" could mean different things to diferent people, and something could be overlooked.
Any recent work on ignition or fuel system BEFORE problem started, or truck having sat a long time, and trouble started when put back into use? Good luck.

Bob · Posted: Sun Oct 18, 2009 9:47 am Post subject: Re: 1970 Chevy C50 backfires

It might not even hurt if he told us what engine it had!

I guess that's part of the game on here... to post as little info as possible to keep the helpers guessing and prying the information out of the poster one question at a time!!

Repair · Regular Joined: 05 Mar 2009 Posts: 51 Report to Moderator

I think you scared him off.
Dont you know whats wrong when it goes like this when i back it up & when i open the trunk the motor dies.
Yea were suposed to know what it is & when we think we got it he will tell us it only does it on a tuesday.

Swantongail · New User Joined: 18 Oct 2009 Posts: 2 Report to Moderator

No not scared off........working. Try it sometime. I didn"t log on here to start an arguement about my internet skills. Just trying to get my old truck running. I have never seen an C50 that had any engine other than a 350 and it "backfires" so it starts with the internal combustion engine. The obvious is the timing, the carb, took off the valve cover and checked the springs and looked for any damage, etc.

Thanks for your "help". I will figure this out on my own

noncompos · Posted: Mon Oct 19, 2009 9:08 am Post subject: Re: 1970 Chevy C50 backfires

Geez, Swan, relax...it was the lack of operating information that was the problem, not internet skills...engines get changed/swapped updated and modified all the time, especially on Ag stuff, so that was a perfectly good point...
You wouldn"t go to a Doc and say "I"m not feeling right, and I don"t have any aches or pains; write me a prescription to fix me"---you"d give him more info...
You catch more flies, and get more help, with a little honey instead of vinegar...Good luck.

Bob · Posted: Mon Oct 19, 2009 11:29 pm Post subject: Re: 1970 Chevy C50 backfires

I guess you ARE going to have to figure it out on your own as your statement "it "backfires" so it starts with the internal combustion engine" really doesn't give any potential helpers much to go on!

bruce omn · Guest Report to Moderator

but we could just give out general tips, like the one I learned the hard way. Backfiring could well be from restricted gas flow. The cylinder sucks in lean and fires too quickly.

Check the gas line filter, or disconnect gas line from the carb and crank the engine. Catch the gas in a can. There should be a half cup of gas after cranking 20 seconds or so.

Bruce