RE: 1992 cbr1000f - Loss of power
 

Air filter clean and looks new, firing on all four hence the good plug colour. It's now down to ignition I think and she is booked in for a dyno check this week.

RE: 1992 cbr1000f - Loss of power
 

I think you should check it out!! I have one too mine makes only 109bhp and she gets to 250kmh in no time!! the fule you use, is it ok?

RE: 1992 cbr1000f - Loss of power
 

If you are talking about 140kmh you must be in SA!! where are from? we must meet up some time!! I am from JHB!

RE: 1992 cbr1000f - Loss of power
 

I'm a Kiwi. Fuel is the good stuff 96+ octane and fuel all replaced at least four times over since I bought her. Bike is being given a once over by a reputable mechanic 2morrow. He is aware of the loss of power, but says that some CBR models have other power restricters that can reduce power to less than 70bhp! Bugger! He didn't offer any advice as to how I can get those missing ponies back, but more will be revealed tomorrow.

RE: 1992 cbr1000f - Loss of power
 

I hope she gets better!! Good luck!

The last thing you whant is a slow bike!

RE: 1992 cbr1000f - Loss of power
 

Even if the bike was a 100 hp version it should run about 225 km/h.

RE: 1992 cbr1000f - Loss of power
 

Are you sure it is not 140 MPH ? ;) Which is a normal top speed for CBR1000F.

RE: 1992 cbr1000f - Loss of power
 

arew u sure you are not "clagging" the rear brake.
i ask cos i sussed that i was having my foot over the rear lever and subconciously putting pressure on it,subsquentially driving with the rear brake slightly on and suspect the caliper became stuck on.
only found out when i changed pads and the bike freewheeled noticably better and felt soo much quicker.
of course u have to come to terms with the 10k rpm gearchanges as well.......

RE: 1992 cbr1000f - Loss of power
 

Mick and Ian at the local Chopper Shop had a look at the CBR yesterday, and the low power of the bike is becoming even more of a mystery, although some progress was made. On the plus side, the ignition timing is okay, and they feel that the bike is mechanically sound, but 50bhp is about it at the moment. interestingly, the boys stripped out the airbox again, and when inspecting the filter element, found that the elements LH air intake was solid, when it should have been open, like the RH end of the element. The CBR has two side air intakes to the airbox, and the element should be open at both ends for optimum airflow. Closing off one end of the element means that the engine is only able to draw air through one intake, and that will affect power. We took the element out, and got a few more horses, but there's something else!!!

It looks like the bike has been restricted since manufacture, and the next port of call is the exhuast system. Silencers appear to be standard CBR1000, but there may be a restrictor in the headers, which would explain the flat performance of the engine. Someone has cut the end baffles out of the silencers, probably in an attempt to gain more power, but the exhaust note is still very quiet. We took a silencer off to see if that would make any difference, and surprisingly, the exhuast note was still quite subdued!! This may indicate some form of gas restrictor further up the pipe towards the headers or in the collector box, so that's the next job. If gas flow is not restricted, then it's back to the drawing board and Ian and Mick have ordered a supply of ignition and other 2nd hand parts from a dismantler to try and eliminate the guilty bit.

Will report back in due course!!!!!!$#@%$#$#$#^%$#

RE: 1992 cbr1000f - Loss of power
 

Sorry I missed those last two posts. No, I have owned bikes for 40 years and knwo the difference between 140kmh and 140mph - Thanks though. No, I'm not dragging the rear brake and even if I was, it would make a lot of difference to the normal performance of a CBR! Mick and Ian are both involved in Classic Bike Tuning and racing, and Mick has owned a CBR1000 before. He reckons that his Kwaka GPZ550 will eat my CBR - Nuff said?