My CRF has a top speed of 55mph ... Anyone help?

I am at a bit of a loss with my CRF:

I recently bought a 2013 CRF complete with FMF exhaust, stage 1 tuner and lower geared sprockets. IT was pretty quick around town but it's top speed (yes I did try everything) was 60mph!. I figured ther ewas a problem with the setup of the tuner and, since the exhaust was absurdly loud, I decided to return it to standard spec.

After much time and money I have refitted the standard exhaust system, removed the tuner, replaced the chain and sprockets with 14/40 originals and had it fully serviced and inspected by 2 garages (one a main dealer). It now has a top speed of 55mph! Which is obviously rubbish!. The bike starts and runs perfectly and pulls well n all gears around town until just over 40 mph, but as soon as the revs get higher the power just drops off a cliff. It feels like it's had a power regulator fitted .. or something like that!

Anyone got any ideas before I have to get rid and start again? Or, does anyone want to by a bike designed to save your driving licence .. no extra charge?

Thanks guys

 

Confirm the air filter was inspected. Looking for something simple first.

 

Not checked that yet!

 

I will check this out over the weekend ... Could be a beer in it if you are right!

 

What size sprockets did it have before? Maybe it has a speedo corrector device installed and now that you have geared back to stock the speedo is off?

 

Have you taken off the fuel tank and maybe pinched a fuel hose? Plugged fuel filter, maybe?

 

oh thanks guys ... these are all things to check ... i will investigate and let you know the lucky winner of "WTF is wring with my bike 2019!"

 

Hope you figure it out!

 

Sorry for the delay .. family 'stuff' to sort out.

I have cleaned the airbox (It was quite coated with mud / dust) and replaced the air filter which has made quite a big difference., it now pulls much harder. I have also attached a TomTom GPS and it's clear that the speedo is a mile out. The GPS 70 and the speedo is around 54. I assume the previous owner has messed around with something which I need to 'unmess'. Anyone know how this works? Do I need a new speedo or is it some sort of electrical gizmo or can I press some buttons?

Cheers

Jeff

 

Glad to know changing the air filter helped. Changing the rear sprocket is a factor here. A speedometer correction computer is available here. http://shop.12oclocklabs.com/index.php?route=product/product&product_id=59. Look to amazon or ebay for a slightly better price. See utube for some how to.

 

PO probably installed a speedo corrector device when they regeared. Now that you have geared back to stock, the speedo corrector will either need to be removed or recalibrated. Below video is an example of where to look for an installed speedoDRD or similar device.


View: https://www.youtube.com/watch?v=3LqTCtTDdJU

 

Oh excellent, I have watched the video and looked at the SpeedoDRD site. It looks easy apart from difficult to reach. I will try and sort that this week. Thanks so much for the help.

 

Ok I have spent quite a while trying to locate the speedo sensor and the SpeedoDRD gadget with no success. It seems that this is going to be a much more difficult job than I had hoped. I am guessing I would have to remove the tank and airbox to have any hope of finding anything. Anyone had any experience of this?