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Discussion Starter · #1 · (Edited)
Okay, so a couple months back i purchased a 95 cbr900rr that was mistreated. Well since then i have overhauled and jetted the carbs, put an exhaust on it and rebuilt the transmission. Well today i rode it hard for the first time and it wouldn't rev past 8k free reving or under a load. If anyone has any idea please help me out i have put so much time and money into it and im about to go crazy because it pulls so strong in the low rpms but when it hits 8 it sounds like the rev limiter. The bike also has a k+n air filter, jet kit, d+d full exhaust, new plugs, new fuel filter, new fuel pump, and fresh oil change.
 

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When you say it sounds like the limiter do you mean it's actually cutting the ignition?
Is the tacho working properly?
 

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Discussion Starter · #5 ·
I know a good bit about cars but im not very familar with bikes so im doing what i can. It definetly sounds like the ignition is cutting to me thats why i think it is the ignition control module. I checked the timing twice already and it was perfect. I just dont want to spend money on something and it not be the problem. To check the tach could i connect a car tach to it and compare.
 

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Or you could just see what speed you're getting at particular revs.
You should be doing something like 5000rpm in top gear at 60mph I think.
If you are only hitting 8000rpm then the bike would be topping out at not much more than 100mph?
 

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Discussion Starter · #8 ·
Is it really supposed to be that high at cruising speed. At 80 my tach reads like 4200 so does that mean that my tach is off. I shure hope so that would make things so much simplier.
 

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I work on around 20kph per 1000rpm in top gear as a general rule.
4200rpm at 80mph is more like what a Harley would be pulling - if a Harley could do 80mph of course :)
I'd figure at 80mph you should be closer to 6000rpm.
5000rpm isn't high - it's less than half the tacho and only 1000rpm into the power.
 

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Check the link I posted above. It will calculate speed and rpms for any given gear for your bike, based on stock or custom gearing.
 

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The only problem with that particular calculator is that it uses a calculated tyre circumference which is about 5% off the actual measured circumference of both 190/50 and 180/55 tyres on six-inch wheels.
The best way is to mark the tyre and the floor and then, sitting on the bike, roll forward one revolution of the wheel and measure the distance travelled to get the rolling circumference of the tyre.
 

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I had a problem where a breather was squashed when I refitted the petrol tank, took the tank off and it un kinked but put the tank back on and it was so it took us ages to find hte problem!! Symptoms were simular to yours. the pip in question was, sitting on the bike, on the RH side near the frame rail and was the breather from the carb float bowls iirc.
 

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The only problem with that particular calculator is that it uses a calculated tyre circumference which is about 5% off the actual measured circumference of both 190/50 and 180/55 tyres on six-inch wheels.
The best way is to mark the tyre and the floor and then, sitting on the bike, roll forward one revolution of the wheel and measure the distance travelled to get the rolling circumference of the tyre.
Good point...missed that fact. :D
 

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Discussion Starter · #14 ·
It was definetly the tach. So at the moment im looking for a cluster or just a tach. If im not mistaken the cluster from a 95-97 900rr will work so if anyone has an extra one let me know. I went riding sunday and it ran awesome so that makes me happy but today i called a local used parts shop and they wanted 250 for a cluster does that sound a little high.
 
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