Help won’t start

[Tonyk]

Bike won’t start 2005 chopper
I’m at a lose where to look next

New battery
New starter
New fuel
Carb has been completely cleaned and adjusted
Proper jet flow has been confirmed
New plugs getting spark
Timing looks correct
Good compression
Only getting the occasional pop

any suggestions what to look at?
The kill switch has never worked, but I’m confused by the fact that I’m getting air fuel and spark with good compression.

 

[Rottweiler]

Single or dual fire coil? anything changed on the ignition?

 

[Tonyk]

Single or dual fire coil? anything changed on the ignition?

Single (stock)

 

[Sven]

Good compression and spark says carb is not so clean = Fuel problem.

To verify, spray WD40 as you crank the engine. Be ready for fire if backfires, etc.

 

[Easyrider]

I'm assuming your problem is crank no start right? The engine turns over briskly but never fires at all? Not to talk down to anyone but did you remover the air cleaner ind see if the choke is closing the butterfly valve? After you try to start the motor are the plugs wet with fuel?

Just a general checklist. Engine needs fuel, air, ignition and all happening at the right time. Easy way to check fuel is to blast the intake with ether. If it fires you likely have an air/fuel delivery issue. You probably know how to pull each plug and see if each is firing with a healthy spark. You said the timing looks correct. How are you verifying that? Easy with points. Not as easy with electronic ignition.

An obvious question: was it running perfectly fine recently? Did you change anything since the last time it ran perfectly? Like a trip to the gas station where they gave you bad fuel? You mentioned a questionable kill switch. If the engine turns over and you have a spark that eliminates the killswitch as a possibility.

 

[Tonyk]

It did run fine until I ran the battery dead and put a jump pack on it, so I will be replacing the ECM. The carb has been run trough pretty good so that should eliminate that

 

[Rottweiler]

So you have spark. You tested compression. Motor spins good.
I would think either not sparking all the time, or not getting the correct amount of fuel.

 

[Rottweiler]

Did you check the ohms on the coil?

 

[Easyrider]

Not for nothing but I would be VERY cautious about replacing the ECM especially if it's just on a hunch. I know a lot of guys who did this and caused themselves massive problems. Do whatever makes you happy especially if you have a money tree growing out back, but instead of shotgunning in a truckload of new parts, try just troubleshooting this in a methodical way. Fuel, spark, timing.

I'm confused. It sounded like your Big Dog is an Evo but now it's sounding like a TC. I don't know if or when BG shifted to TCs, FI and ECMs but exactly what motor do you have on yours? Evos went the way of the moose (on Harleys) circa 1999. You have a carb, a single fire ignition and an ECM?!?!? What does "the carb has been run through very good" mean? You can completely eliminate the entire fuel system by trying my starting fluid hack. If you're getting a spark to both plugs your timing would have to be waaaaay out of whack for it not to fire at least sometimes. If you have a fat spark at electrode that pretty much eliminates the coil.

When an engine turns over briskly but does not fire at all the problem is almost always something VERY basic. Even an evo that has a hole in one of the pistons but is otherwise fully functional will fire intermittently and try to start. Ask me how I know.

 

[Snuffy]

Most likely the jump pack burnt up shit. You can send your Ech to Curtis for testing before buying one. It could be many things but most likely something electrical

 

[Mikeinjersey]

It did run fine until I ran the battery dead and put a jump pack on it, so I will be replacing the ECM. The carb has been run trough pretty good so that should eliminate that

2 weeks ago you said the bike would not start. I'm assuming you solved whatever issue you had and this is an new issue. I agree with Easyrider that you should hold off on replacing the EHC.
Judging from your post all was well until you jumped your bike. Troubleshoot the bike first before you invest in a new EHC and it's a good idea to take Snuffys advise to have Curtis at https://www.wildsteedworx.com/ after you have eliminated other possibilities.
If your new battery went dead it could mean that your charging system is not functioning properly or it was a bad battery. If so you can address that after you get the bike running again. Recharge or Replace the battery and begin troubleshooting. Turn on the key and look for fault lights on the top of the EHC for clues. Hit the run button and verify the Ignition module is getting power indicated by a red light coming on. Hit the start and see if the bike cranks with no start or just no crank at all.
Pull the air cleaner off and look inside the carb to see if fuel sprays inside when you hit the throttle.
Re-test for spark , no need to test compression again. The ignition module gets power directly from the EHC and distributes power to the ignition coil; signal is provided by crank position sensor. Timing and dwell is set from the factory and not adjustable.