TheSamba.com :: View topic - 1974 Super with relatively new motor from Brazil

Fri May 02, 2025 4:46 pm

I have had this Super for over 20 years. It always performs well. The other day I went to work and it started backfiring when it was warm. I could'nt get it home afterwards and had to get my tow bar. It backfired really loud and pretty much died on the way home. Bad backfire! So I thought it was intake and replaced the boots, gaskets, swapped carb, did wires, plugs, etc. After all that it was hard to start but ran like a champ for 15 minutes until warm and I was far enough away to have to go get tow bar again. Exact same, terrible backfiring, enough to kill the engine again. Read some stuff on YOuTube about condenser. Did that. Won't start, have spark, carb is good. I did not do points but have had a dozen bugs and this has never happened to me ever. Scratching my head...

Fri May 02, 2025 6:27 pm

spray some aerosol starting fluid into the air cleaner or carb, try to start, do this a few times. If it runs for a few seconds then quits out, you have a fuel delivery issue, start there. If it won't run at all when you do this, then it's a spark issue, work on that. This is a common first test to help isolate the problem. This is practically an ALWAYS: isolate whether spark or fuel. And remember: just because the engine can crank/spin engine fine, doesn't mean that the electrical part of the ignition switch (the "run" circuit) is OK. If it's a fuel problem, CAREFULLY check to make sure fuel is reaching the carburetor.

Sat May 03, 2025 12:52 pm

Have great spark, Fuel pump is good, I am thinking these carbs may be trashy. One is Chinese junk and the other is a Redline. I have not rebuilt them just cleaned them with complete disassembly and blown out all jets. Float seems fine. I am still perplexed on the massive backfires that occurred with both. I will rebuild the Redline with a kit. None of this makes sense at all. Nothing is old at all. It does NOT backfire through carb, and no wires are misplaced. Fuel delivery is great from pump but the Redline is not squirting. It does fire alittle but more of a pop and never runs. It did that the last time with carb swab. Thanks for the suggestions but these are rudimentary things I have done in my sleep. There is something else going on here. Thanks again.

Sat May 03, 2025 2:04 pm

I would say change the condenser. Looks like you did that. Sometimes new condensers do not work either. I try to test all condensers I send out because of it.

Thu May 08, 2025 1:29 pm

Might run a compression test on it. Maybe something happened within the valve train?