Rejetting?? An opinion... for what it's worth

Purchased a 04 Fatboy mid May. Hadn't driven it 2 blocks before it "coughed" through the carb. I had never owned a Harley prior to this one, but had logged many hours on an Electra Glide in the late 80's and early 90's as a Police Officer. I only had the performance of that bike to compare to the new one. I put about 500 miles on the bike and it still occassionally "coughed" through the carb, hesitated on throttle response, took forever to warm up, and just didn't "run" as well as the Electra Glide. Anyway, I took it back to the dealer who told me I was comparing apples to oranges and that was "just the way they ran". Because of EPA standards on emissions, the carb was set so lean the bike was starving for gas. He suggested a stage 1 conversion at the 1000 mile service. Long story short........After 1000 miles, I rejetted the carb, added a Ness Big Sucker high flo air kit, and changed the exhaust to Vance and Hines Bigshots Staggered. All I can say is..... WOW!!!!!. The bike now runs flawlessly.....never "coughs" and the only time I have to use the enricher (choke) is to start a cold engine. Before, I was having to run the enricher out just to get it to run for the first 5 minutes. Anyway......there are 2 reasons for the post. 1. Why do I have to pay 18K for a bike that won't run right and spend close to 1000 dollars to make it run right? 2. I ask the Harley dealer to "richen" up the carb when I took it back. He said he couldn't do that because it would be in violation of EPA standards. Why then is it not against those same standards to rejet the carb for more fuel flow to accomodate the enhanced air flow created by the additon of the air kit and performance exhaust. Dont get me wrong....I wouldn't trade this ride for anything now and am just venting I guess. For those of you with a a bike that hasn't been rejetted (carb) or remapped (EFI), dont wait, spend the money. It's an unbelievable difference in performance, smoothness, and all round driveability of the bike......for what it's worth.

I'm about to jump through this same hoop when I do the Stage 1 upgrade to my '04 Heritage Softail. I'll be back to describe my own 'wow'.

But on the carb thing... I have the EFI and never experienced the problems you mentioned. In fact, your problems are the reason I opted for the EFI over a carb. My rebound question to you is how did you analyze the rejetting to get it right?

Glad that you overcame the difficulties, and yeah, $18K +++ to get it all perfect stings. I'm up to $22K right now and still going. HD is a Big Boy Toy.

Yea....the carb/versus EFI will always be a big discussion. Some like carbs and some like EFI all for their own reasons. I opted for the carb because I can always find someone to work on a carb and I know a little about them myself. In addition, rejetting a carb is a lot less exspensive than converting EFI to stage 1. Plus.....I'm not sold on Harleys EFI system. From What I understand, their system does not include a sensor in the exhaust gas flow. All modern EFI sytems that I know of have a sensor in the exhaust gas flow which let the computer know how the bike is running so as to make the proper adjustments...etc etc. To me (and I know this may be BS) but a carbed bike sounds different. I like the sound of the carb under heavy acceleration, but I know everyone who has an EFI bike prefers them and I'm alright with that too. I could be totally wrong about my comments about the EFI system, and dont want to satr a big argument....it's just an opinion. As far as the question about which jets, I had that work done by a mechanic. I told him I was installing a Vance and Hines system and he decided which jets to go with based on that system. I have to say, he hit it right on the money. Thanks for the reply

EPA and your rights

Get used to it by 2010, EFI will be pretty much standard on all motorcycles as will be some form of liquid cooling. All makes will have Catalytic converters also. The EPA has recently blamed motorcycles for significantly contributing to air pollution and has adopted the Republik of California's standard for emissions to be implemented over time. http://www.epa.gov/otaq/roadbike.htm since the mental mindset of the EPA is a sort of blend between Gestapo and back door big industry graft, we were thrown to the lions.

An air-cooled engine has to run almost too lean and is always on a tightrope between death rattle and EPA illegal. Lean pop is the universal result.

The EFI systems on motorcycles are about the same technology as the 85 Chevy Throttle bodies were. They are all open loop with very few exceptions like the Buell and some others. The VTX1800 owners are amongst the most vocal of their EFI being so lean it pops all the time. The Triumphs have EFI in some models and they are experiencing lean pop.

It isn't H-D or Honda or Triumph that is the problem. It is the because of the sudden unfounded, unwarranted, overzealous, new standards implemented by big government, The great Republik of Californification, Sierra club and any other Jackass that wants to run your life.

Concerning costs the initial cost to get the product needed to tune the EFI (Power Commander, HRT, DFO) may be higher than a Carbed version initially but not for long if you go beyond a basic stage one.

EFI Stage I

Big Sucker $89

Exhaust same as Carbed say $400.00

Since a free flow set of exhaust will not work well with an H-D Stage I flash, we need a way to add fuel like a Carbed version.

DFO / TFI $170.00 Allows you to adjust the fuel curve.

Total: $659.00

As with the carb model no changes to RPM limit or timing curves.

Carbed Stage I

Big Sucker $89.00

Same amount on exhaust $400.00

Jet Kit, Yost or Dyno Jet, SE (made by Dyno jet) average $100.00

Total $589.00

Difference: $70.00

Now this is where it gets interesting. Let's say you want to add cams, punch up to 95" etc.

The DFO / TFI might hang in there but not likely. The carb kit might have large enough jets so no big deal.

EFI:

Dyno Jet Power Commander PCIIIUSB. We now have total control over timing and fuel and can map each cylinder independently.

$285.00

If we want a higher RPM limit, time for the H-D flash. $150.00

Total: $435.00

Carbed version:

We now need to be able to control the timing curve and want a higher RPM limit.

Crane HI4TC or other box street price averages $250.00 on sale.

We sell a ton of Mikuni HSR42 Easy kits for this setup. The CV will work fine but we find that most want the faster throttle response the HSR or S&S give.

Mikuni HSR Easy kit $250.00

Total: 500.00

The difference in Stage I between EFI to Carbed was $70.00 to the Carbed side.

Going HI performance was $65.00 to the EFI side.

Net difference $5.00

There are many, many scenarios that can and do alter this formula but the basic principles remain the same. Add air, you must add fuel. Add more air, more fuel and control of timing. Some H-D shops charge more and some charge less for just doing a flash of the EFI.

There is a fallacy about which is more likely to fail also. The Carbed bikes use the same basic sensors to determine RPM, crank and cam position and intake vacuum / pressure the EFI has a throttle position sensor. Both have boxes that are computers that are subject to the same voltage fluctuations, weather conditions, etc. The carb jets can get plugged with debris just as the injectors could so where is the reliability different? Like I said, the current EFI is much like a Chevy throttle body and both are basically electronically controlled carbs.

One of the biggest issues we will face as we approach 2010 are the new fine structure and other legal issues a dealer or independent shop will have to deal with. While enforcement is currently lax to non-existent the new rules require ever tightening scrutiny.



Now, you would expect that H-D like the other large manufacturers fought the good fight trying to save the day and get the EPA to either back off or slow down right? Wrong! They are in the Governments corner all the way. Why? Because they want the smaller companies like Big Dog and many others to comply with the same rules as they do. They know it would put most out of business, as they cannot afford the R&D. What about S&S etc? H-D does not want competition and they and so many others get a slice of their pie. Greed and total domination is and has been H-D modus operandi for years.



I believe there is a much more detailed version in the most recent American Iron rag.

KWalker,

About 100 miles ago, I added Vance & Hines longshots and a Ness Big Sucker. I have been waiting until my 1000 mile service to do the rejet, however the bike seems to be running great. I haven't pulled the plugs to see how it's burning, but from outward performance and sound, it's pretty darn good.

I keep hearing stories about HD wrenches not getting the jetting right, and I have a couple friends who work for indy shops and I know that they know what's up when it comes to carb work. I guess I'll still rejet it, either from a buddy or HD, but I wonder how much of a difference it will make?

Also, does the service manual give instructions for a rejet? I've actually been thinking of tackling it on my own.

It isn't H-D or Honda or Triumph that is the problem. It is the because of the sudden unfounded, unwarranted, overzealous, new standards implemented by big government, The great Republik of Californification, Sierra club and any other Jackass that wants to run your life.

Ah, come one CD. Tell us how you really feel.

Chrisrg,
I bought my fxdwg new in 02. I have never worked on motorcycle carbs and have very little experience with any carbs. Most all of my experience was listening to friends talk about carbs and how they worked. Anyway, I installed a set of samson street sweepers and a hyper charger and did the carb work myself. With the help of my local harley dealer over the phone. When I put in on the dyno to my surprise the dyno tech told me the only way to get it any better was to tune it with a dyno! The hardest part was finding what plug to drill out for the fuel/air idle screw!

****.....

all I really was doing was venting and bragging a little about my newly rejetted bike.....I never knew about any of this BS going on behind the scenes. ****.......thanks for all the info......

My bike had an aftermarket exhaust when I got it. It always ran with a lot of hesitation and heat. Since the pipes were really discolored, it hurt to look at them. I decided to take on the whole project of new pipes and re-jetting the carb.

Let me tell you, it is now like a new bike. No more hesitation and smooth as silk. The heat stays at a safe range. I probably added a ton of mileage to the engine by doing this. Now I have a 1991 that runs like a 2004...

Just wanted to share my success!

That's great Harley Z,

I'm picking mine up today from having the rejet done. It was running pretty good before, so I'm hoping I'll now get the full benefit of those pipes and aircleaner.