Tuning problem

[fantomaz]

Hi guys...

I am the (not so) proud owner of a 2004 bulldog...

I recently did the wire plus conversion when my ehc died, i also changed my ignition for a dyna 2ki, but i still don't manage to get the thing working properly....

I tuned the carb as per the instructions found here, my plugs readings are normal, but I have this (very annoying symptom):

When i start the bike it runs a bit erratically for the first few minutes, then it runs ok for about 15 mins... THEN it starts missfiring around 2000 revs, as if it had a problem going from the idle to the main jet. When I open wide it catches up, but there is always a hesitation around 2000/2500 revs... The severity of that condition varies from a subtle hesitation to badly missfiring and running on one cylinder...

Makes the bike very dangerous to drive in traffic and drives me crazy, any ideas?

Thanks in advance...

 

[fantomaz]

bump...

 

[alhall88]

Did all this get done at one time? What your describing sounds like a fuel issue but did it run fine after the wire plus mod? Lets start with spraying some carb cleaner around the intake manifold while the bike is running and see if you have an intake leak. Did the bike run well after the ignition change? What curve are set at, timing? What jet sizes are you at right now? Sounds to me like too small of a main jet if everything else was fine your right at the transition point.

 

[fantomaz]

I did the wire plus first, and after that the bike was running very rough, then I did the dyna 2ki, that improved the bike considerably but it's still not perfect, far from it...

Before the conversion I found some laquer debris stuck in my main jet, I cleaned them and installed a fuel filter right before the carb... I'm gonna take the bowl out and look for more debris, you never know...

I am running curve n°1 on the dyna (I have 98 octane gas here in Belgium)

What I dont understand is that it runs pretty ok for the first 15 mins, it's only when it gets real hot that the sutttering, farting in tha carb, running on one cylinder etc starts... and it only occurs when I am on the idle circuit, when I open wide it catches up and runs ok...

 

[fantomaz]

Upon further inspection, there is indeed something wrong, the little copper tube on the to left of the carb is normally closed by a rubber cap, my rubber cap had cracks in it, i am replacing it with a piece of the evacuation tube.... we'll see...

 

[Raywood]

Upon further inspection, there is indeed something wrong, the little copper tube on the to left of the carb is normally closed by a rubber cap, my rubber cap had cracks in it, i am replacing it with a piece of the evacuation tube.... we'll see...

That's just your accelerator pump, won't cause the issues you are describing.

Pull the fuel filter and see if that corrects the issue. Sounds like it's not suppling enough fuel for you as many on here have found out with some filters.

 

[fantomaz]

OK, I'll try that, but I will have to find some replacement filter at some point.

A few months ago, I had the same sort of symptoms, but it was all the time, not like now when it happens only when the bike is real warm...

I pulled the bowl and found some lacquer debris obstructing the main jet, so my guess is that the mesh filter on the petcock is broken...

I imagine someone must make a high flow fuel filter...


I'll try that tomorrow, and I'll also try to get hold of some brake cleaner to check for an intake leak...


So much has gone wrong with this bike in only three months of ownership... :-(

 

[fantomaz]

Ok, it seems that I have an intake leak, when I spray on the manifold with a water based spray the rpms drop.

I looked for a loose screw, but found everything pretty tight...

I have bought some blue silicon manifold gaskets, would these work on my bike?

What else do I have to check?

Thanks in advance!

 

[fantomaz]

Oh, FYI I pulled the fuel filter and there was no change at all....

The conditions worsens with engine temperature, so it makes sense with the intake leak theory, no?

 

[stlmikie]

That does make a little sense. When the bike getts warm the metal expands and the leak occurs.

 

[Raywood]

Your carburator seals are rubber not gaskets. They are pinched/squeezed between the head and manifold. You may have dry rottem seals and need to replace them for a tight seal.

 

[fantomaz]

Yep, but there were two types of these at my local harley shop, some black rubber ones, and some blue silicon ones supposed to resist heat better, I went for the silicon ones, they were also a bit different in size... (my guess is that the silicon is softer and thus compresses differently, hence the size difference...)

 

[fantomaz]

Took the intake manifold out, I found no evidence of a leak either where the manifold meets the heads or between the carb and the manifold.

Both o rings and both seals are intact.

I'm thinking maybe some of the water I sprayed might have gone in the filter, hence the change in rpm...

Now there is something weird with the manifold, it looks a bit bent (look at the pictures) what do you think?

Do I need a new one?

Also, do i put the black seals back or do I try the new blue ones made of silicone?

What I DID find was a lot of the same lacquer debris stuck in both jets (no more filter remember).

It would have been impossible for the bike to run properly with these stuck in the jets, the way they were stuck, they were restricting the flow of the gas quite a lot...

I am taking the carb completely apart and cleaning everything...

Still, nothing explains that the symptoms were worse when the bike was real warm...

I am starting to feel BD ownership is more about problem solving than riding, I had far less problems with my 1972 (AMF) FL based chopper (that was hammered together in spain, by someone with no skills, just a blowtorch and a hammer) than with this supposedly "state of the art" custom...

 

[fantomaz]

BTW, I ordered a new pingel petcock, a new hose and a new hi flo pingel in line gas filter...

 

[Raywood]

BTW, I ordered a new pingel petcock, a new hose and a new hi flo pingel in line gas filter...

I've never seen the blue seals before. If they provide a tight fit then use them not that you bought them. If you are getting that much crap in your carb then you do need to run a filter just make sure it has a hi-flow output. The Pringle should be ok. You most likely didn't need a new petcock. Did you pull it to see if the screen was clogged with tank liner other other debris?

The petcock only has a screen to catch large debris so it shouldn't be considered a filter.

I would give your carb a thorough cleaning then put it back together and see how she runs. Also what kind of aircleaner are you using? If you have a velocity stack or cone filter you should remove the bowl vent.

Good luck

 

[fantomaz]

I have the stock air filter...

I havent pulled my original petcock out yet, but by the size of the debris going into the carb, I am pretty sure that the mesh is destroyed...

This bike was previously imported in Lithuania, which is a very third world country, various cues make it clear that it has known a lot of problems that were adressed with very limited equipment or knowledge...

What I know is that the EHC was changed cause it was the later type (with adapter board) when I replaced it for the wire plus module.

When I changed the ignition for the dyna 2Ki, the pickup had marks like it had been tried in dozens of different positions. The timing plug had been removed using a metric allen key, damaging it.

The admission manifold screws were also damaged by wrong tools, that also means that they were at least removed once... Which could explain why the manifold is a bit bent, btw I still would like your opinion on that (pictures in my previous post), do I need a new manifold?

 

[lee]

sounds like you need to flush your tank through

 

[fantomaz]

I did it when I put the new wiring harness in, but there is still debris...

Still no opinion on my bent manifold?

 

[Raywood]

Still no opinion on my bent manifold?

Now that you mention it I've seen that flat spot on my manifolds also. It may be normal. Shoot S&S a pm, they are responsive and will answer your question quickly.

 

[fantomaz]

They said the flat spot is fairly normal, and easily cured with a wooden dowel.

Out of interest, they also said that you should'nt use HD seals, as they are too thick and will dent the manifold...

I have ordered the seals, I hope this damned bike will work one of these days soon...