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Old 02-13-2018, 05:54 PM   #18
sqwert   sqwert is offline
 
Join Date: Jun 2017
Posts: 382
Quote:
Originally Posted by Thunder View Post
My experience with bore kits all else left alone is not a whole lot more horsepower, but a wider powerband and peaks at lower rpm. I expect the difference to compare to that between Honda's 100 and 125 cc singles from the early '70s. Only 0.5hp gain claimed, but the 125 was much gentler to keep in the powerband, more competent with loads and increasing grade. Same way with the TW200 and TW225 Yamahas.

Lots of complaints about the RX3's cammy nature, this might be a cure. I expect the big bore will complement the EFI. My experience with street EFIs is most are versatile enough to adjust themselves to a few more CCs. CSC has already provided us a decent curve, I don't expect the bore will screw it up. I can think of several dozen other more desirable upgrades that would cost the same or less than new programming.

Lots of complaints about the RX3's tall final drive, with limited options of sprockets not prone to more rapid wear, powerband wider and at lower rpm might contribute to a cure, especially making a couple teeth on the wheel sprocket ideal with the stock 14 countershaft for those of us who do long miles. I expect hard core offroad to still be a lot better with a 13, but I don't do that type riding with my RX3.

Thinking about it, I'd like to have a bit more performance on the highway, but I really don't want the extra weight of the RX4. I expect this bore kit, perhaps with a little port polishing to retain top end, but no porting that would kill the lower powerband, will be the compromise that moves the RX3's position in my garage up a notch or two.


 
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