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Old 09-05-2012, 06:14 AM   #33
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Joined: Aug 2012
Location: Saint John, New Brunswick, Canada
Oddometer: 234
Originally Posted by frost1 View Post
Thank you for your reply. The owners manual recommends shifting to 6th at 37mph (60 km/h), I get up to 50mph (80 km/h) and feel like the bike is really working. I twist the throttle and it very slowly accelerates from there. I'm also concerned with winding out the motor too much. For me to hit 75 mph (120 km/h) the bike would be screaming. Is that the case? But w/o a tach I have no idea what it's doing. You mention "bouncing off the rev limiter", how do you define that? I probably do it all the time mistakenly if you mean to rev it up with the clutch in while shifting.... I need to get that under control. It feels like I'm working this bike very hard just to keep up with traffic. Not what I was expecting. But then again I have no point of comparison what so ever. So it could be me and this is how it is. Maybe more of a street tire would help. I'm dropping the extended warranty today because I may actually sell this bike in the coming months once I get my skill level up.

Well until you have it full broken in i wouldn't try bouncing it off the rev limiter. Engines have an inbuilt limiter that prevents them from reving beyond their safe RPM limit, what it will feel like is the bike dying, then coming back and dying again etc for as long as you keep the throttle pinned. What it is doing is hitting max RPM, then automatically dropping down for a preset amount of time, then going back to max RPM. It's the engines way of telling you to back off. Shifting to 6th at 37 mph is pretty conservative. I've maxed mine out once on the highway, that was in a full racing tuck, down hill and I hit 140km/h, I had the throttle pinned to the stops and never hit the rev limiter, I don't think I could on this bike, I think my weight and the wind ressitance I casue because of my size means that the bike is always working and won't hit the rev limiter. ONce you are well beyind the prescribed break in period, and after the first oil and filter change do a little experiment. Sit on the bike with it off the sidestand, in neutral and progressively increase throttle input, it can be scary but I;ve done it one 30 year old inline fours of questionable upkeep, this allows you to gauge the RPM limits with the seat of the pants meter. I certainly don;t recommmedn it on a brand new engine as the first 500-1000km is still the bedding in time fro all the moving bits, excessive RPm in this period can either cause them to not bed in properly or destroy themselves. After the break in period though it would take pretty poor vehicle operation to destroy a modern engine. Like Isaid they are made with automatic safeguards that will prevent you from blowing them up.

I would imagine that an engine like this one, originally designed for the CBR250R, would have a pretty high RPM limit, not as high as an inline four mind you, but higher than you would think, they were originally designed for a diminutive race rep bike. I haebn't done any diggin yet but I imagine there is info on CBR250R owners boards as to RPM limits and when the rev limiter will kick in. They are still the same engine with the same dimensions and specs, changes to exhaust and intake have changed the power delivery and I imagien the rev limiter has been lowered, but it's the same engine and will have the same physical limits as the CBR engine.
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