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post #1 of (permalink) Old 04-27-2018, 10:42 AM Thread Starter
Jason Pittenger
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Question Ear Shave Performance Question

So, I've been reading through this forum quite a bit, but I cannot seem to find a conclusion.

Does the Ear Shave help performance?

Some say yes (the bike breaths better), and some say no (you lose the the surge tank added mid-range torque).

The procedure I found says to rejet from stock 132/38 to 142/42. This is a size of 107.5/110.5% compared to stock. This would imply one of 3 things:
1. A power increase of 7.5% to 10.5%.
2. Increasing fuel 7.5% to 10.5% changes the bike from running lean to running rich. It sounds like it's factory tuned lean to accommodate emissions, and allow for better high altitude running.
3. An efficiency LOSS of 7.5% to 10.5% and no net increase in power. Thus, a 7.5% to 10.5% loss in MPG.

So is there any conclusion on this? I'm not interested in cosmetic only mods. I can't justify the cost/time if I don't gain a boost somewhere. If that's the primary purpose, I'll pass on this mod (but I don't judge those that do it!).


'89 Vulcan 750 Bought 4/12/18 @ 17805.9 miles $800
Purchased stock. Wrecked once
22490.0+ miles

Completed modifications:
Removed mufflers, straight pipes out of GB
110/90 Front Tire
Pick-up coil re-gapped to .020"
Compufire 55402 r/r series regulator
USB Outlet + Voltmeter
Repainted Metallic Blue w/ new tank bages
Ear Shave (wo/ coasters) 40/140 NO shims 45MPG
MCCT conversion

Planned modifications:
Custom LED turn signals
Highway Pegs
(Possible) ignition advance
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