Aloha from Hawai‘i. I have a 06 Softail Deluxe that the previous owner has modified. While it runs ok, there is a spot in the lower 1/3 of the RPMs and at part throttle (think daily riding, commuting, traffic) where it’s as if the motor cuts out completely for a second. Completely silence, cut out, always in the same spot of the RPMs and normally where I want to be while cruising around. There is also small puffs (not full on backfires) during deceleration, this is a minor annoyance compared to the dead spot.

The current mods to the bike are:

Sampson True Duals w/ 33” Baffled Long tails
K&N filter on stock base w/ stock football cover
S&S 585 gear drive cams
Dynojet Power Vision w/o wideband sensors

I plan to purchase the wideband sensors if need be as the exhaust has the o2 bungs but have been told that autotune may not be able to fix this problem. I’m also thinking of buying the speedo/tach combo gauge to help figure out exactly where the miss occurs. I know the best way would be to dyno tune but being new to Harley’s I’m not sure there is a dyno on island and even there is a person capable of creating maps. The previous owner said he would just throttle through and ride in a lower gear/higher RPM. If I hit the throttle harder then there isn’t an issue but if it can be fixed it would be a better riding experience. Any suggestions would be helpful, should I try to run the basic autotune? Will replacing the air cleaner with something that has better flow help? Is it the cam install messing with the set up? Opinions of if the widebands would correct my issues?


Thanks in advance

 

My knee-jerk reaction is email Fuel Moto, Jamie or Bob will get back with you, and there really helpful.

I'm learning about the power vision and target tune myself, so I'm not 100% sure but I believe you need to have the wideband O2 sensors for the target tune to work, (Fuel Moto will know so do the folks on this forum). I would try to target tune it for starters, YouTube has a good video on how to do it, worst thing that could happen is it won't work (it won't read the exhaust gas's)

 

Thanks! I think I can do a basic auto tune without the widebands but the programmer will be limited on what it can read and change. I'm hoping this will help correct any spark issues. I will get to ordering the widebands in the next week or so. I will also send Fuel Moto an email and see what they say.

 

Do you know all that has been done to the engine. 06 softies came with 88" and those cams are not considered a bolt in cam as they require much higher compression.

585: Designed for 88 to 95 CID engines with compression ratios from 9.7:1 to 10.5:1 and 100 to 124 CID engines from 9:1 to 10:1 compression. Provides massive horsepower and torque increases starting at 3000rpm and holds steady all the way to redline. 3500-6000 rpm for 88" - 103" engines and 2500-5500 for larger engines.

 

As far as I know it’s a stock motor. All the previous owner said was the cams, gear drive, and adjustable pushrods. What is the stock compression ratio? Maybe that could be the cause of the problems...

 

If the cams are the culprit I may as well live with the hole in the power band until I can upgrade the cylinders and pistons to a high compression 96ci or similar. I doubt any amount of dyno tuning will fix a part that shouldn’t be installed correct?

 

Yes. Those cams need compression which can also mean headwork. Try to figure out what you have before making any dicision. You can easily and cheaply do a compression test and that will tell you somethings. Can you ask the seller for receipts or what was done?

 

I messaged the guy and hopefully he responds soon. I may just go to O’riely to rent a compression tester kit to find out for certain. Without headworks the motor would just not run at its potential correct? Not blow itself up right? The hole in the powerband can be lived with or may signal something catastrophic? First harley and should’ve bought a stock one but couldn’t resist the look of this bike!

 

Yes, get info from seller and check compression. And when you say "hole" not sure if you mean the bike is cutting out, wanting to die or runs very bad, backfiring... or just weak performance until you get the revs up. The later would be typical of a bike thats over cammed.

Prefer not to comment on the motor blowing up without riding it Others may commit a better answer.

Their is always the option of taking it to a dealer or shop.

 

Feels like the bike cuts out but you can pull the clutch and raise rpm above that point to get past it or just throttle harder right past it. But since this is my first harley I don’t know what is typical and yes it could be right at the point when the cam makes power so it’s a dead spot. Similar to how I had to put in higher stall torque converters in my cars to get into the cams power band off the line