2006 Ultra Classic Backfiring

[Robert110763]

Hi all,
       My twin cam 88 cub, backfires when trying to start hot, any suggestions would be greatly appreciated.
 Thanks
Robert110763 

[Hossamania]

A little more info would help. Any mods, hi flow air cleaner, exhaust, tuner, etc? Is the air filter clean? Has the throttle body been cleaned?
How old is the battery? Make sure your battery cables are tight, battery is fully charged. Check the charging system.

[60Gunner]

TC88 is carbed. So most likely a carb/choke issue. But does it have the stock ignition module?
Does it backfire thru the carb or exhaust?

[fbn ent]

TC88 is carbed. So most likely a carb/choke issue. But does it have the stock ignition module?
Does it backfire thru the carb or exhaust?

Nope, not all and none in '06.

[Hossamania]

TC88 is carbed. So most likely a carb/choke issue. But does it have the stock ignition module?
Does it backfire thru the carb or exhaust?

Nope, not all and none in '06.

I figured being an Ultra Classic it was efi, and also thought '05 was the last year carb was an option.
And as mentioned, not all TC88 were carbed as the MM efi has been out since '96?

[WhipLash96]

Has any work been to it recently? Could be a head gasket going out or the seals on the intake are going bad or loose. If it is carb, I had issues with the choke, especially with AM cables. They SUCK!

[60Gunner]

Totally missed the year. My bad. If it's MM I would've converted to carb tho.

[fleetmechanic]

Last M and M EFI system was 2001.  2002 and up are all Delphi.

[OldBogie]

Unfortunatly with EFI and it's neighbor electronic ignition it can be difficult to figure whether this is a mixture or a timing problem, especially if the engine can't be started and run to where non electronic observations can be made. The days of screw driver and pliers repairs are over.

Assuming that both systems are operating as they should the backward home shop analysis would lead to fuel supply and that could be the pump or supply to the fuel pump or filter, if not water or styrene contaminated fuel can be ruled out.

Your likely going to need a shop with test gear for these systems. And people wonder why I keep my 2000 Heritage?

Bogie

[Hossamania]

No feedback from the OP, hard to diagnose without more info.

[smoserx1]

No feedback from the OP, hard to diagnose without more info.

Hoss you got that right for sure.  I just looked on Ronnie's website, and in 2006 some touring models were still available with carburetors.  I believe he mis-stated his model too, as far as I know ultras were always EFI only back then.  Some other models had carb/efi choices, but enough about that.

Mine is carbureted and will sometimes backfire when starting.  Did that just the other day.  The battery is 3 years old and although still works pretty good, it is certainly not new.  I got a feeling that when the battery gets old it can cause misfiring during starting when the battery is using most of its juice to power the starter and that can could raw fuel to pass through the engine & explode in the muffler when the bike finally fires off.  Just another of my theories, you know how that goes.

[Hossamania]

My carbed bike with a Thunderheader sometimes backfires so loud at startup that it sounds like a gunshot. Scares the hell out of anyone around. I kind of like it.

[kd]

My carbed bike with a Thunderheader sometimes backfires so loud at startup that it sounds like a gunshot. Scares the hell out of anyone around. I kind of like it.

Now add a kick start to that combination and ..... well you know the rest.      In some cases that backfire can cause damage to the starter components, especially over time.

[HogMike]

My carbed bike with a Thunderheader sometimes backfires so loud at startup that it sounds like a gunshot. Scares the hell out of anyone around. I kind of like it.

Now add a kick start to that combination and ..... well you know the rest.      In some cases that backfire can cause damage to the starter components, especially over time.

My EVO with the carb will do that sometimes.
I especially like it when I do a hot start in front of the dealership and watch when they all duck!

Yes, that's the way my neighborhood is like.

 

[60Gunner]

My carbed bike with a Thunderheader sometimes backfires so loud at startup that it sounds like a gunshot. Scares the hell out of anyone around. I kind of like it.

Now add a kick start to that combination and ..... well you know the rest.      In some cases that backfire can cause damage to the starter components, especially over time.

My EVO with the carb will do that sometimes.
I especially like it when I do a hot start in front of the dealership and watch when they all duck!

Yes, that's the way my neighborhood is like.

 

Haha. Too funny.
Mine is getting there too. 17 years ago when I bought this house it was a nice quiet street. Hardly a car driving down it with my bike being the noise in the neighborhood.
Now days, gunfire and SWAT raids are becoming more common just blocks away.