Harley Davidson WL difficulties to start

[epazikas]

Dear colleagues, perhaps you can share with me some of your experiences you may have had when starting a Harley WL.
My motorcycle was completely serviced in September and it was running well; among other things the carburetor was totally dismantled and serviced by a professional, the timing was adjusted, condenser and spark plugs replaced, gear cam serviced and everything else you can imagine. Also the manifold was replaced and there are no leaks. All runned perfectly until November.
Now the challenge:
Now it is winter time and I can not use the bike as I wished. Last time when I had a ride, the bike sudden lost the power and would die if accelerated (idling was ok). Once at home I could not find anything abnormal, but when I try to start it (please check the video I did), the bike misfires and a flame gets out of the air filter cover. What could be the problem?
I never got these flames before. The only thing I did before the problem popped up was to insert a bit of MMO (Marvel Mistery Oil) on the fuel tank. Could be this an issue? Should I drain the fuel tank?
This is the video clip I did:

https://youtu.be/QWq1jlP1dtE

I hope you can suggest few checks? Thank you! Ed

[Sargehere]

"the bike suddenly lost the power and would die if accelerated (idling was ok)."

Timing is off if it is firing with an intake valve still open, backfiring through the carburetor.
Welcome to the asylum.

[epazikas]

Hi Gerry, thank you for your answer. Might seem to be a silly question, but what is the problem? Because I never had the situation before...what are your recommendation so that I can start the bike again?

[duffeycycles]

first off..it looks like you are retarding to prime & then full advance to start....read the instructions again!
Also this is colder,maybe leave the choke on part way when starting.

[slamiste]

Ed,
Lots of things can cause your problem. I've had something as easy as a bad condenser cause issues similar to what you describe. Here's what I'd do if I was in your shoes:
1. Verify the point gap and timing are correct. If OK..
2. Check valve clearances. If OK...
3. Check to see if cylinder compression seems about right. For this I'd simply remove both spark plugs and push my finger into the hole while kicking over the engine. If compression feels about the same and pretty strong on both cylinders then...
4. Set carb high and low speed needles back to settings used for starting with an out of adjustment carb. Turn both needles in (clockwise) until they seat (count turns in from original position so you can put them back if it turns out the carb wasn't the issue) then turn out the low speed needle about 3 - 4 turns and the high speed needle out about 1 1/2.
5. Try and start the bike. If the problem persists them I'd start with charging electrical items. Start with the plugs, if no change replace the condenser, if no change check the coil, if still no change then I'd go get a beer of two and call it a day.

[T. Cotten]

Welcome Ed!

Once you have double-checked everything in the service manual as Slamiste suggests, yet performance is still poor,
please try this simple diagnostic: http://virtualindian.org/11techleaktest.html.

Vacuum leaks are evil.

Good luck!

....Cotten

[epazikas]

Hi, thank you very much for these steps, I will have a try tomorrow, however I have a question about the spark grip. I usually retard it (clockwise or outwards) when priming and then advance it (anti clockwise or inwards) when starting the bike. Is this incorrect? Thanks for confirming this, Ed

[Paps]

If you added the Marvel before refueling the oil may have not mixed well. Drain the tank, blow out the disconnected fuel line at the carb with compressed air, and refuel.

[epazikas]

Hi Cotten, thank you for sharing this. I have done this test already after I replaced the manifold in September due to the leaks. All is sealed properly and no leaks. I will save this link for future references. Ed

[BigLakeBob]

If you are using a foam air filter cartridge I would remove it until you resolve your problem, that little fire at the end of your video could cause real havoc if the foam filter were to engulf.

[epazikas]

Hello! Very good point, thank you! I am currently using K&N air filter, so I will remove it and replace back the original until the issue is resolved. Once again, thanks... Ed

[kitabel]

If you added the Marvel before refueling the oil may have not mixed well
Your float bowl may be full of MMO.

[ChiefTwoKicks]

I'm a bit confused... you said you retarded the spark advance while priming the carb.. then advanced the spark to start the engine. Try this... retard the spark for the prime steps (kick it over firmly, sometimes only one kick, but more often just two kicks, open the choke half way, then start the bike (with spark retarded, half choke), after the bike starts, open the choke slowly and advance the spark slowly to full advance... then allow the bike to FULLY warm up to operating temp. (maybe 5-6 minutes, especially in cold weather)... after ALL these steps, then proceed to adjust the carb for performance. Pay close attention to Cotten's comments !! He ALWAYS says something about intake air leaks... bubble test is the best. Cotten says the same thing so often, there must be a reason why !! So many people get impatient and neglect this MOST IMPORTANT step in setting up a bike to run properly. Way too many bikes are out there, running with intake leaks. Sometimes, these leaks are so small, they don't show up easily (even with a bubble test)... then the destruction begins, usually with poor performance. As the poor performance continues, it leads to hard starting, burned valves and piston crowns, and more. It doesn't take long for the destruction to occur. Check the timing again, in the FULLY ADVANCED position. From your description, it sounds like you're pretty close to getting it right !! Sometimes, it takes just a little more tweaking to get it correct. When you can get your bike to start on the first or second kick EVERY time, hot or cold, then you know you finally got it right !! Good luck, some people settle for a lot less. don't be that guy !! C2K

[epazikas]

Hi, thank you! I have drained the fuel tank and cleaned the fuel pipes now, just to secure that there is nothing left. The float seems to be ok and working well. I will have a try on the next couple of days and will post the outcome here. Ed

[epazikas]

Hello, today I have checked all these steps and all seems to be in order. Out of these, I noticed that the hexa screw that goes on top of the carburetor valve was loose so that I could remove it by hand (attached picture), perhaps this was part of the problem as the float working conditions should be affected.
Other things I did was:
1- Temporarily replaced the K&N air filter with with original one, just for the case a misfire can happen again.
2- I noticed that the spark plug cap, in one side was not very tight. I have fixed.
3- Cleaned up the spark plugs
4- I drained the fuel tank and replaced the fuel.
5- The fuel pipes from the tank to the carburetor has been cleaned
That is all for now, I will try to start it to orrow or the day after, when the weather improves.
Thank you, Ed