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Discussion Starter · #1 ·
I have been having an issue with one of my 748s, where it would "pop" at anything below 5,000rpm. The sound was almost like a relay clicking, but it sort of sounded like it was backfiring into the airbox. Then the bike went back into service, and the dealer replaced the coil pickups (bike died on me one day after the original repairs was performed).
I got it back yesterday, and while the noise has almost completely gone, it still does this on occasion.
This evening,while riding it to the grocery store with my face shield up, it did it again. This time, it almost sounded like an afterfire pop in the front of the bike, at the horizontal cylinder.
Thoughts? This has me stumped, and apparently, my Ducati stumped, as well, as he was made aware of this issue when the bike came to him, the past two times.

1997 Ducati 748.
Unbranded carbon fiber slip-ons.
Exhaust wrap.
No other mods, that I am aware of.
 

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i would say it's a bit lean, but that's on the assumption that all the baseline shit (and idle mixture setting is part of that) is all ok.
 

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TPS set correctly?

Vacuum leak from TBs to charcoal canister?

Lean?

Voltage issue?
 

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Happened with my 748 a few times as well, IIRC ended up being my TPS. Bike was running lean and backfiring into the airbox.
 

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Discussion Starter · #6 ·
Could also be as simpel as a leaking exhaustgasket....
I thought about that, but it has good compression.

TPS set correctly?

Vacuum leak from TBs to charcoal canister?

Lean?

Voltage issue?
What is this charcoal canister, in which you speak of? ?
Yup, that has been deleted.

Happened with my 748 a few times as well, IIRC ended up being my TPS. Bike was running lean and backfiring into the airbox.
Part of the service performed last week was a new TPS and calibration.
 

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Discussion Starter · #7 ·
i would say it's a bit lean, but that's on the assumption that all the baseline shit (and idle mixture setting is part of that) is all ok.

Don't know what they're paying you around here, but it isn't enough. ?

The air runners were not properly clipped into the airbox, causing air to bypass the seal. I reconnected them, and resolved the issue. My guess is, this, combined with the aftermarket exhaust, caused a lean condition.
 

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Discussion Starter · #8 ·
My thanks to everybody who contributed!
I removed the fairings and slid the fuel tank back to flush the coolant system, and in doing so, had noticed light shining through in the gap between the air runners and the airbox. Both my runners were unclipped. I reconnected them, and the issue seems to have gone away.
 

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Hmm, I believe you.

I cut out the belly out of the airbox, my runners are held in place by the fairing, and the Time Machine runs just wonderful.


I still believe you, (edit) but make sure those fuel hoses are seated in the tank. I rode about 90 miles with them held in by nest of wires between the tank and the head. Ran with a similar issue as you describe.
 
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