New member & Questions

[JRE.66]

I bought a 79 Special back in March and it appears this forum will be very helpful in getting it running. I haven't been around to work on it, but I decided to make a post to see what people's thoughts were.

I bought the bike non-running and the previous owner claimed that the bike was running days before I bought it. He said he was riding up and down his street but it shut off and wouldn't restart. He seemed to think it may need coils and he also claimed to have rebuilt the carbs over the winter (but he also said it might need floats, so I guess those weren't included in the rebuild). The bike cranks over but just wouldn't start. The bike has pod filters and a 4-into-1 Kerker exhaust, but I don't think that would cause this problem.

One thing the owner did say was that he said he was running the bike off a gas can in his lap. He repainted the tank and didn't want to spill gas on the newly painted tank so he ran the fuel lines to a small gas can. I've heard of some older bikes having vacuum operated petcocks on the tanks to pull gas to the carbs. Do these bikes have that system? If they do, could it simply be that the carbs couldn't pull gas through the lines by themselves?

I'm basically just throwing stuff at the wall and seeing if anything sticks. This is my first foray into a project bike so I'm seeing if anyone with more experience has had a similar sounding problem.

Thanks in advance for any help!

[gtem]

Try feeding the carbs directly. This would require pulling the tank off or at least putting in some sort of union to connect to the fuel lines running from the petcocks, and put fuel directly in the two lines that feed the carburetors (two lines lead to two fuel "t"s that split and feed carbs 1 and 2 and carbs 3 and 4. This should atleast eliminate plugged/non-opening petcocks from the equation. More likely than not, you'll be pulling the carbs to properly clean and check everything over. I shudder when I I hear that someone has "gone through" or "rebuilt" the carbs. In 90% of cases, they used cheap junk parts and tossed the original jets. The fact that they installed (likely, cheap) pod filters is another worrying sign. The *right* kind of pod filters can be made to work, but it takes really knowing what you're doing and using the right filter boots. If you happen to have the stock airbox, you'll be much farther going back to that and OEM Mikuni jets.

[Socer4m]

HI, try GTOM method,,,,
quick check for gas from tank to carbs,
1. ,TURN THE PETCOCK TO PRIME,,,GAS SHOULD FLOW FREELY, you can also pull off the gas line at the petcock out while its turned to prime and gas should flow freely. IF gas is flowing next check,,
2, CHECK FOR SPARK...pull off one of the outside plugs, ground it to the engine case and crank over the bike,,should see a bluish spark, if so your coils are firing.
3. Also, these bikes need a full charged good battery to fire the plugs, check the voltage at the battery,,,should be at least 12.4 v and also check while cranking, it shouldnt drop much or battery is not good.
4. Also can shoot some instant start into the carbs or air cleaner inlet and crank over, if it fires up a bit, also shows the coils are firing....
5. a lot of us have pulled off the vacuum octopus from the petcocks and just run staight lines from petcock to carbs and eliminate vacuum problems,,others swear by them, whatever...
keep us informed, Mike in S. Diego and Pa

[Radioguylogs]

"It might need floats" does not instill confidence in the carb rebuild.

Were they full of gas? If yes, why didn't he replace them? Otherwise, why would he say this if he knew what he was doing?

Anyway, Soccer4m has a good suggestion for a diagnostic procedure. If you follow it exactly, there may be a big ball of fire on step 2.

[DEEBS11]

Unfortunately this sounds like you have inherited some else's bad workmanship and/or bad (Chinese) parts. If the jets in the carbs look shiny you may have counterfiet parts. Socer4m's procedure is a good start. This a bad filter.

[DEEBS11]

[DEEBS11]

Do not cover these holes. Any of them.

[LAB3]

You could cut out the parts of the lip that cover those ports, I've seen people doing that on videos.

[JRE.66]

Thank you for the info!

I agree that it seems suspicious that the carbs were rebuilt but the floats weren't replaced. I am assuming that I will have to do a once over of the carbs. I feel like rebuilding the carbs is a bit of a right of passage but I will admit that the Murray's Carbs kits are very tempting (although a bit pricey).

What exactly are those holes that you're saying not to cover up? Some sort of vacuum ports, I assume?

[DEEBS11]

Air jets that combine with pilot fuel jets and float chamber make up air orifices. If you block these areas you will have guaranteed problems. Add Chinese parts and your problems are exponential.