I’m having trouble getting my 2000 sportster 1200 to start, this is what I know.

1. Battery has a good charge, 12.8v
2. I replaced the ignition module, coil, spark plug and wires. I’m using an ultima system. Static timed at TDC
3. I’m getting a spark at the plugs
4. Engine compression is F215psi R200psi. I’m not sure if that’s too high but the numbers are within 10% of each other.
5. I cleaned and rebuilt the carb. After rebuild it was leaking through the overflow and pump housing cover. I adjusted float and replaced the o ring on the pump cover to stop leaks. I’ve taken it apart again (didn’t remove jets) and sprayed carb cleaner and compressed air through everything again.
6. When starting it cranks but won’t fire, it will backfire through the exhaust, sometimes front cylinder sometimes rear. If I use starting fluid it will backfire through the carb and will backfire if given throttle but won’t start. Stock jet sizes. The nozzle that sprays gas into carb is working fine and will wet plugs if used.
7. I don’t have a vacuum fuel valve it’s gravity fed. Fuel filter is clean and when I removed the carb I tested and made sure that I was getting good gas flow through the line. The gas tank is new.

 

If you did not remove jets, you probably forced some crap into them by using carb cleaner and compressed air. Sounds to me like your pilot jet is clogged, based on your symptoms.

John

 

Pull the carb and clean the jets.

 

If the pilot is clean, (I use welding tip cleaners) it almost sounds timing related. Unfortunately, I don’t have any experience with timing carb sporties, all my stuff is EFI.

Good luck.

 

Jets aside, one wonders why it won`t fire on starting fluid ?

 

Hmm, I missed that part. Good question...

 

Sounds like timing. Why did you mess with the timing in the first place? What started all of this, does not sound like it was just sitting for the Winter, which is the usual scenario. Sounds like there was a problem, you threw a lot of new parts at her, and the problem remains. With spark, compression and starting fluid it should fire off, timing is the place I would look. Good luck.

 

@knownothing 1. As above, may be timing. Are you sure you used the correct TDC?
2. See reference information below for timing and reference here for further information on troubleshooting: http://sportsterpedia.com/doku.php

Ignition Timing - Adjustable 1986 Thru 2003

• Ignition timing is when the spark takes place - specifically as the piston is traveling UP on the COMPRESSION stroke (compressing the gasses so that you get the most out of the explosion/ignition). 6)
• Top Dead Center is when the piston is at the VERY top of its travel, in the center of it's dwell area, and is usually referenced to mean on TDC of the COMPRESSION stroke (with the valves closed and the mixture compressed), though the piston will also be at TDC on the Exhaust stroke when the flywheel turns one complete rotation in either direction from TDC of compression. 7) So, the piston will be at TDC twice per 1 full revolution of the cams. Timing is measured (and set) from TDC on the compression stroke. Check below for the images of cam notch on timing rotor position relative to TDC Compression or see more on Finding TDC on Compression Stroke in the Sportsterpedia.
• Spark ADVANCE - is how soon, BEFORE the piston reaches top dead center (all proper timing is BEFORE TDC) that the spark plug fires to start burning the mixture. The faster the motor is turning, the sooner you need to start the ignition (more advanced it needs to be) so that the power of the expanding gasses starts pushing on that piston as soon as it starts moving downward and pushes as long as will be beneficial. 8)
  • Ignite it too soon, and the gasses start pushing down as the piston is still coming up (spark knock, pinging etc). 9)
  • Ignite it too late, and you loose a lot of the power of the gases, since the piston will reach bottom before the gasses finish expanding. 10)

http://sportsterpedia.com/doku.php/t..._-_engine_-_05

Find TDC (compression) Using the Timing Mark on the Flywheel (57-03)

2004 and later models do not have timing marks on the flywheel.
(Base Timing on them is set in the programmable Engine Control Module using a CKP Sensor at Flywheel Teeth)

• 1957-2003 stock flywheels have TDC marks and advanced timing marks for timing the ignition.
• You can use the TDC mark etched into your flywheel on 2003 and prior stock engines to find TDC.
• The marks should be accurate enough on these engines although True TDC can be checked if need be.
  • Click here for stock 57-85 TDC symbol identification.
  • Click here for stock 86-03 TDC symbol identification.
• If you've upgraded to a 2004 or later flywheel assembly, (on 03 and prior engines) you'll have to make your own TDC mark on these if you need one.
  (this procedure can also be used to create the advance timing mark)

• The bike should be on a jack or a lift so you can spin the rear wheel.
  (although it is possible to roll the bike forward in gear)

1. Remove both spark plugs: (or one on each cylinder for dual plug heads).
   • This will relieve the compression on the engine as you turn the engine over.
2. Establish how the engine will be rotated.
   Caution: Turning the rear tire while the transmission is engaged may produce up and down movement of the entire bike.
   Make sure it is tied down and secured before attempting to rotate the tire.
   • With the transmission in high gear, rotate the rear wheel in the forward direction (bike on a jack or lift).
     • This is easier done with two people;
       • One turning the rear tire and one watching the timing mark in the inspection hole.
     • However, it can be done with one person;
       • Rotate the rear wheel slightly, check piston position using a straw and repeat until the piston is close to TDC.
       • Then nudge the rear wheel forward until the TDC mark appears in the timing hole.
   • With the transmission in neutral, rotate the crank shaft or pinion shaft with a wrench.
     (no compression to put undue stress on the pinion shaft)
3. Remove the timing plug centered between the two cylinders:
   (57-90 left side of the engine, 91-03 right side of the engine).
   • Use Caution while removing / installing this plug.
   • It is a steel plug in an aluminum hole and it's common to either destroy the internal threads / sealing surface or to find them to be damaged upon removal.
4. Rotate the engine forward.
5. Listen or feel for compression building in the cylinder as the piston rises
   • Verify when the cylinder is on the compression stroke while rotating the engine by use of an indicator in the spark plug hole.
     (forced air past the indicator shows compression is building in the cylinder):
     • You can use the finger method below to feel when the cylinder is pushing out forced air.
     • You can also use a TDC whistle with the same principle.
   • The window in time where both valves are completely closed begins on the compression stroke, with the closing of the intake valve. 17)
     • Both valves stay closed through the rest of the compression stroke, and then most of the following power stroke, at which point the exhaust valve opens.
     • Compression TDC sits just about half way in between those two events.
6. Once you have verified the piston is moving up on the compression stroke, stop rotating the engine.
7. Anticipate to rotate the engine forward to the nearest TDC mark from here:
   • Slowly rotate the engine until the TDC mark is in center of the timing hole.
   • This will be your ending point of rotation at TDC (compression).

NOTE:
The above information, while credible, is worth what you paid for it and should not be considered gospel.
Do due diligence, research and have a H-D Field Service Manual before working on your bike.
You will probably have many opinions and suggestions presented; make sure you research the person providing the helpful information as there are some who provide good information that is useful and some who speak out of other orifices with gibberish. You will figure out this quickly.