06' Dyna Street Bob Cams & stumble?

[1slos10]

I just swapped my stock cams for a set of SE-203's this past weekend, and it has the HD Race Tuner on it and 2-1 V&H Big Radius. When I first start the bike in open loop it seems to run fine and has a good clean smell from the exhaust, but after it goes into closed loop as engine temp comes up it has a pretty bad stumble if you are going down the road and you hit it pretty hard and get out of it, then try to ease along at 1/4 throttle or less( I assuming its going back to closed loop) it stumbles pretty bad, but if you crack it back open (a little more than 1/4 throttle) it picks back up and runs like a scolded dog. The bike still has the 8* injectors and the MOCO will be changing those Wednesday to the 25*. My question is do you think the injectors are the problem? The plugs look very lean to me( white and lightly speckeled metallic). I am sure the bike was on the verge of lean before the cams as it used to stumble some with the old 2-2 Big Shots I had on it, and seemed better after the 2-1. I dont have a cable to try and edit the CLB table so I guess im just stuck for now. Thanks,

Ronnie

[FLTRI]

Ronnie,
First let me verify your comment about the engine running lean as delivered from the factory. The pipe just added to the leanness in especially the cruise area,
Now that you have changed cams the fuel requirement is so different the bike should run like crap.

While you have a closed loop system it is for cruise rpm/tp and relies on correct VE tables to modify.
So changing the closed loop bias table that only works in a limited area in an attempt to get the system to completely change the fuel for the all rpm/tps cannot work.

There is no way for the system to tune itself.....you are too far out of the ballpark for that to happen.

What you need is a proper tune and everything will work correctly and you will not toast you engine.
Get it to a competent tuner,
Bob

[1slos10]

It has the SERT on it but it has the base map for exhaust, air filter and 8 deg injectors. Map # 141NX002-BO.MT6. I hope the injector swap Wednesday cures some of it and may have to dyno tune when I get some extra cash. Thanks for you reply

[FLTRI]

It has the SERT on it but it has the base map for exhaust, air filter and 8 deg injectors. Map # 141NX002-BO.MT6. I hope the injector swap Wednesday cures some of it and may have to dyno tune when I get some extra cash. Thanks for you reply

You do not have the mufflers the SERT was written for which completely changed the fuel requirements. The injector swap may help an idle issue if you have one but will in no way change the tune for your build. It will still be lean and run poorly until the VEs are tuned to your build's configuration.
Don't feel bad, a lot of folks think their bike will run fine with a canned map for a build parts used in lieu of the ones the mapping was developed for.
Bob
PS - It runs OK when the bike first starts because it is much richer, then when the engine warms, the AFR goes considerably leaner...based on the VE tables.

[1slos10]

Changed injectors to the 25* per the TSB for my bike, and loaded a canned map for a 1550 & 203's tweaked the VE Tables a little for my 1450 and ran the CLB tables up to 798.

[FLTRI]

Changed injectors to the 25* per the TSB for my bike, and loaded a canned map for a 1550 & 203's tweaked the VE Tables a little for my 1450 and ran the CLB tables up to 798.

That'll get you to a tuner so the VE tables can get corrected for the changes that are not HD formula. (exhaust)
If you think it runs good now, you will be amazed how much smoother, more responsive, and more power you can get after a good tune.
Bob
PS - The canned map you used was for the 25* injectors? These new injectors put out more fuel than the 8* original ones, so if you used an 8* deg map with 25* it will be quite a bit richer.

[1slos10]

It was a 25* map, believe the one I used was 141NW102..

[FLTRI]

It was a 25* map, believe the one I used was 141NW102..

OK, that is a lean mapping (emissions) for 25* injectors with slip-on SE shorty mufflers.
You have a 2into1 that changes the fuel requirements significantly.

You can guess at what you may think it needs and modify the mapping, but how do you determine what rpm/tp you are in and how that corresponds to the AFR table?

Unfortunately there is little you can do unless you purchase an O2 setup, weld bungs into your pipes, mark your throttle grip for % throttle from the data mode of a tuner, then drive around making note of the AFR in all the tps and rpms.
Then come back and make changes to the mapping for the cylinder you made notes for, then repeat the process for the other cylinder.

This can take a bit of time and effort and there are those here that have accomplished a reasonable tune this way, but you cannot guess at it or you can really find mileage has suffered or engine temps go high.
Good luck in your endeavour,
Bob

[1slos10]

That tune is for closed loop bike, I have a 06' Dyna (Closed Loop). I'm not using the tune for the rest of the bike's lifetime, its just to buy me a little time until I get the 300.00 for Dyno Tune. I rode it about 300 miles yesterday and pulled the plugs this morning and they looked great. Local dealer has $25 Dyno runs this weekend, so I will be able to tell where I stand as far as A/F goes. Dyno Tune may come in a month or so, not real sure at the moment...

[FLTRI]

That tune is for closed loop bike, I have a 06' Dyna (Closed Loop). I'm not using the tune for the rest of the bike's lifetime, its just to buy me a little time until I get the 300.00 for Dyno Tune. I rode it about 300 miles yesterday and pulled the plugs this morning and they looked great. Local dealer has $25 Dyno runs this weekend, so I will be able to tell where I stand as far as A/F goes. Dyno Tune may come in a month or so, not real sure at the moment...

OK, now I see where you are a bit mislead or under the wrong assumption(s).
1) Your closed loop bike can only run properly in closed loop IF the VEs are re-adjusted to actual target tailpipe AFR. (yours is not because of the exhaust change)

2) For $25 you will get a WOT run that will only tell you where the AFR is @ WOT only. (not where you ride which is 99% of the time @ part throttle. Maybe you can get them to take a quick peek (for a couple bucks more?) @ part throttles and rpms to see how lean/rich the areas where you ride are.

3) Saving the money for a proper EFI re calibration/tune now could cost you much more later due to lean-running damage from the VE tables not being correct and the closed loop system not being able to pull the AFR into line with targets.

I have no monetary interest in your decision, just want you to be clear about what your closed loop (cruise area only) is capable of correcting for, which is mainly temperature and altitude. I believe you are confusing a wide band, closed loop system to your narrow band closed loop system. (even those have to be close for the closed loop to operate properly)

Proper re-calibration to the EFI mapping is not a luxury, it is a requirement that few realize and try to skip to save a buck, yet buy bobbles for their bike that has no performance enhancement.
An analogy is mixing the ingredients for a cake in a bowl and eating the batter instead of baking it. The batter tastes fine if that's all you have tasted, but is much better tasting after it is cooked.

The difference here is eating the batter instead of cooking the cake doesn't cost money in the event the batter goes bad.
Bob

[1slos10]

I understand very clearly what the difference is in Narrow & Wideband. I also understand that my ve tables are not perfect. I also dont believe for a minute that every bike that Harley builds has to have a necessary 4 hour Dyno tune, if you swap exhaust & air cleaner. A can map is exactly as it sounds, not bike or condition specific. When Harley sells you a Race Tuner they are comfortable letting you install a canned map and dont force a 300.00 Dyno down your throat. I also know how to read plugs and my plugs tell me my bike is not lean, from a human, non 02 sensor, view, I can tell the bike is running safe enough that even if I never dyno tune, my bike is not gonna melt down within the next month. I can remember when there was no such thing as a dyno and also when there were no 02 sensors and bikes had these funny looking deals called carburetor's and people had to use plugs to read how there bike's were running, no VE Tables, No wide or narrow band 02's, and some how with enough knowledge they managed not to burn up everybike in production before the fuel injection age came along. Like I said before, I know I need a dyno tune but I would bet out of the 1000's of SERT's & SEST's, about less than 20% actually buy the full blown Dyno Tune, and the other 80% are still riding.

[FLTRI]

Ronnie,
First let me apologize for irritating you.
That was not my intent and feel kind of silly trying to explain why you have  "a pretty bad stumble if you are going down the road and you hit it pretty hard and get out of it, then try to ease along at 1/4 throttle or less".
I didn't realize you knew what the problem was and how to remedy it.
Sorry for getting involved,
Bob
PS- Your comment: "A can map is exactly as it sounds, not bike or condition specific."
Here is the specific configuration the 141NW102 calibration you said was in your bike. Note they are so specific with the exhaust they actually call it out by p/n:

Application:   2006 Shotgun / Shorty Dual Exhaust with O2 Sensors "Closed Loop"
Configuration: 1550 Stage 2 (95" - yours is an 88"?)

Components:
  25 deg Injectors P/N 27709-06
  SE Air Cleaner and Breather Kit P/N 29440-99B
  SE 1550 Big Bore Cylinders P/N 16546-99 or 16549-99
  SE 1550 Flat Top Pistons P/N 22851-99A
  SE 203 Cams P/N 25937-99B
  SE II Slip-Fit Mufflers P/N 80349-00A or 80258-99A
Are you sure about what you speak?
Just trying to help a fellow rider,
Bob

[lonewolf]

Bob, you are a patient man.

[FLTRI]

Bob, you are a patient man.

Just tryin' to help a guy understand how his EFI actually works rather than what is assumed to be happening with his EFI.
Some want to know, some do not want to listen because it is not what they want to hear.
Bob

[1slos10]

Hey guys, I had the bike dyno'd yesterday, like I said before, I knew it wasnt dead on but altleast I know where it stands as of now. The leanest the A/F got was 14.5 at near 5200 or so during the WOT Power pull, we are looking to bring that down around the 13.9-14.1 range. At idle it pretty rich around 12.9-13.0, which I could already tell from the smell of the exhaust at idle. During the cruising pull it ranged from 12.9 up to 13.9 or so. It made 78hp & 81tq, which the dyno tech said we could really improve with the tuning due to the 14.5 A/F at WOT. The 02 was read at the front 02 bung, because we couldn't get the probe in the muffler. I didnt mean to come off like dick earlier, I understand everybody is here to help, Sorry if I made that impression earlier..

Ronnie

[FLTRI]

Hey guys, I had the bike dyno'd yesterday, like I said before, I knew it wasnt dead on but altleast I know where it stands as of now. The leanest the A/F got was 14.5 at near 5200 or so during the WOT Power pull, we are looking to bring that down around the 13.9-14.1 range. At idle it pretty rich around 12.9-13.0, which I could already tell from the smell of the exhaust at idle. During the cruising pull it ranged from 12.9 up to 13.9 or so. It made 78hp & 81tq, which the dyno tech said we could really improve with the tuning due to the 14.5 A/F at WOT. The 02 was read at the front 02 bung, because we couldn't get the probe in the muffler. I didnt mean to come off like dick earlier, I understand everybody is here to help, Sorry if I made that impression earlier..

Ronnie

Ronnie,
No  problem. Now that you have an idea of where the AFR is on the front cylinder (variable), the rear is actually the cylinder the fuel requirements change the most from the exhaust change you made.
WOT could be as high as 15.5:1 or higher due to the way the 2into1 flows compared to the old 2into2 system.
You will be surprised at the improvement, not only in overall power, but responsiveness and smoothness once the VE fuel mapping is maximized for each individual cylinder, as it is this balance of fuel that makes the most difference from dyno tuning. WOT graphs are great for showing but part throttle is where the most time is spent riding, specifically under 20% TP.
While I realize there may not be the budget for a proper tune, just remember there is improved power and overall performance, including mileage just waiting to get let out.
Regards,
Bob

[1slos10]

Im hoping to be able to get the dyno done soon, my local dealer usually runs winter specials on dyno's & motor work, and a good friend of mine is the head tech, and he's gonna talk to the service manager about helping me out with a early winter special dyno. Hope he can make it happen, so I can get it tuned properly. Thanks for the help and patience Bob!

Ronnie