CBR 1000F "Hurricane" 1987-1996 CBR 1000F

Poor performance

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Old 06-02-2010, 02:32 PM
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Unhappy Poor performance

I'm sure that most of you guys have pushed your old girls to the limit? How fast did she go?
Some time ago we had kind of "top speed" run at the small local airport.
It was about 1 mile / 1700 meters run with a standing start. They measured the speed at the 1700meters with a police radar.
I only did one run but that was horrible, not sure whats wrong with the bike. My topspeed was amazing
216km/h.. Jesus.. My old old volvo would've been faster
Some years ago I was there with my ex Cbr 1000f 1992 and it was quite a lot faster going 240kmh..
My bike is orginally from germany and I think they used to have max power limited to 100hp? Or what could it be wrong, im sure it should go faster.

Heres link to the results http://www.liy.fi/tulokset/index.php...ed&only=&rev=0 .. quite embarrassing
 
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Old 06-02-2010, 03:59 PM
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Hi Mik76 , are you complaining of general poor performance , or just disappointed with the results of your run?

If she's running well otherwise , then she may as you say be restricted , otherwise there is a whole list of things to check , let us know what you mean

BTW welcome to the forum
 
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Old 06-02-2010, 04:11 PM
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If she's running well otherwise , then she may as you say be restricted
Yeah, I'd check on the carb boots to see if your air flow is restricted. Maybe you could also somehow check by the vin number??
I'm not sure how fast a restricted one will go, either.
 
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Old 06-02-2010, 04:22 PM
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Thanks!

I think its running fine except it feels little bit slow. At least when comparing to my old Cbr which was year older and had driven more.
 
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Old 06-02-2010, 07:22 PM
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That power limit thing rings a bell for me. If it turns out not to be that, then I'd start with a compression test to rule out a couple of major things (worn rings, valve seats etc.) Does it burn oil or use more fuel than you think it should? If the compression is ok then you'll have to look at your carbs. It might run fine through most of it's range but could be off when you're wide open for a speed run....still good fun to have a blast on an air strip.
 
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Old 06-02-2010, 08:01 PM
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The limited power version is the German GII version. It actually sounds like it could be the case.

Here is a picture of some restricted carburetor tubes on a different bike, but it's a general representation of what you're looking for:



Also, I came across an article about a restricted R1 (from france) where Yamaha basically used bumpers on the carb butterflies to stop them from totally opening up. The owner was saying that his bike would get up there in speed (well over 100mph), but was struggling enough that he couldn't keep up with a 600cc Suzuki at top end.
Interesting!

The 150mph (240kmh) speed that you mentioned with your last bike is more like what it should be. Gearing can change that, but if your RPMs weren't topped out, that's not the case.
I believe the restriction was 100HP to the wheel, which seems to make sense.
Obviously other factors could come into play here (carb issues, etc etc), but I'd look at the possibility of restriction first since it's easy enough.
 

Last edited by kilgoretrout; 06-02-2010 at 08:10 PM.
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Old 06-02-2010, 10:42 PM
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Trout is correct - 108/110 BHP at engine, 100 BHP at the wheel, on some German models.
My top speed 261KPH at sea level, with bigger freeflow exhaust, Dynojets and a K&N filter.
Your bike sounds as though it's restricted.
Some of the bikes sold in Switzerland were also restricted, I've read.

Check your sprocket size, too, may have something to do with it. I run 17/42 (standard)
 

Last edited by Shadow; 06-02-2010 at 10:47 PM.
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Old 06-03-2010, 09:48 AM
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The first thing I would check is the ignition timing. If the timing mark is on the "T" mark at idle, and stays there when reving the engine, your pulse generator needs to be replaced. $50 bucks for a new one, and a simple replacement job. Makes a big difference in acceleration and speed when the ignition is advancing correctly. In 20 years, mine has gone bad twice. I think the engine heat gets to it.
 
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Old 06-03-2010, 11:50 AM
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Just looked my registration documents.. there it says 72kW
Soooo.. at least it has been a restricted once. Must go check those carbs asap
 
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Old 06-03-2010, 11:57 AM
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Never would have thunk. They do that to our shower heads and toilets too. I rip them right out.
 


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