An intake backfire caused one of the stock throttle body blades to bend, preventing all of the other blades from closing properly.
The stock blade screws are peened on the backside...
...and have countersunk Phillips heads on the other.
The stainless blade simply slides into the same slot that the stock one was removed from. Then Loctite the stock screws, tighten them and you’re finished.
Apply tape over the injector and vacuum holes to prevent contamination from any metal shavings.
Use a grinding tool to shave off the peened area, then crack the screw loose with a screwdriver, making sure to have a solid bite and proper fit.
Without fully grinding the backside of the screw and using a tight-fitting screwdriver the screw heads will be ruined—like these. They had to be drilled and extracted. Take your time and use the right equipment.
It always seems that the most frustrating mechanical glitches occur at the worst of times. Electrical issues can have you chasing your tail for days in search of the problem, and fueling hiccups can also be a nightmare. Most times, these things seem to pop up out of nowhere when least expected.
On highly tuned bikes running a power adder there’s a common issue that has ended many trips to the strip early, but the preventative measure is quite easy. We’re referring to a bent throttle body blade caused by an intake backfire, typically caused from a lean condition in the fueling. The backfire has such force that it can drastically bend a stock throttle body blade, thus throwing the blades out of sync and causing the idle to hang (as much as the blade is bent).
Sure, you could probably remove the bent stock brass blades and straighten them one way or another, but the easier solution is to swap them out for stainless steel blades that are much stronger and less likely to bend. Installing a “preventative upgrade” may seem like a hassle to some who would rather wait until (if) it’s necessary, but why risk ruining your day, particularly when the situation can be caused by something as simple as an accidental bounce off the rev limiter or missed shift?
Orient Express Stainless Throttle Body Blades