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P.J., Technician
Category: Motorcycle
Satisfied Customers: 750
Experience:  10 years as a mechanic and fabricator in a privately owned, local, custom bike shop.
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I have a 2008 Ultra. Over the winter, I had T-man do his 107

Customer Question

I have a 2008 Ultra. Over the winter, I had T-man do his 107 inch kit, and did the recommended MAP from Thundermax. Bike started immediately and ran fairly well although I was getting some popping at idle. I took a 200 mile ride and it ran ok, although not great but I was varying speeds. 2 weekends a go I put new plugs in and immediately it ran fantastic, then the next day the front plug totally fouled. We replaced the coil and it once again ran fantastic, then the next day, both plugs fouled. Any ideas?
Submitted: 2 years ago.
Category: Motorcycle
Expert:  P.J. replied 2 years ago.
Hi, my name is ***** ***** I'll be working with you today.
It simply sounds like it is just running rich. Figuring out why can be the tough part. A little more information may be helpful.
Are you running the Thundermax in closed loop (using wideband O2 sensors) mode? Have you performed an auto-tune after the initial mapping?
Do you have the Thundermax software?
If so, have you sent a data collection in for them to take a look?
Thanks, P.J.
Customer: replied 2 years ago.
I haven't sent a data collection in yet, but yes I'm running the closed loop system. Yes I'm also using the Auto Tune and I uploaded the Map they suggested. Everything was running very well overall for the first 250 miles now I'm getting the fouling problem.
Expert:  P.J. replied 2 years ago.
The O2 sensor check is the Thundermax recommended first step for a bike with your bike's symptom.
First make sure you don't have your stock O2 sensors still plugged in too (I've seen it more than once).
Next, make sure your seat pan isn't pressing down on the main harness plug leading into the Thundermax. Aftermarket seats are typically the only seats that cause issues but it is a common problem and can cause all sorts of issues.
Then, if you can, plug it in and look at the two AFR monitors while running and see what those AFR's are doing. This will tell eliminate one or both O2 sensors, their wiring, or the possibility of a problem in the O2 section of the Thundermax. They are pretty bulletproof but do occasionally have issues.
I'd definitely do that data collection if you can. I've sat in a room with those guys while they went through them and it is pretty amazing how good they get at nailing down problems just by looking at a big screen TV full of numbers.
I hope this helps. Please let me know if I can be of further assistance.
Thanks, P.J.
Customer: replied 2 years ago.
I will give that a try and see what happens. Thank You.
Expert:  P.J. replied 2 years ago.
You're welcome. P.J.