Engine won't rev past 8500 rpm in 5th and 6th gear

frbld600

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I have a 2018 RC390 with a full Mivv exhaust and Rapid Bike Evo installed. The engine seems to run smoothly and pulls great in 1st-4th gears; however, in 5th and 6th gears it won't rev past approximately 8500 rpm and will now only hit an indicated top speed of about 85 mph. Any thoughts on what may be causing this? A tech at Rapid Bike told me they didn't think it was related to the Rapid Bike as it doesn't utilize any gear sensor information.
 

KTMasean

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When did this start? After installing the exhaust or EVO?
Does the engine rev past 8,500 rpm in 1st to fourth?
Are you riding the OEM sprocket set?
What Rapid Bike tech are you referring to, a factory (Italian) guy?
Did your bike rev past 8,500 rpm in 5th and 6th before?
 

frbld600

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Seemed to happen after the exhaust and Evo were installed together. Engine will fully rev in 1st-4th gears no problem. It is the OEM sprocket. Tech was from their importer in Orlando. Revved out in 5th and 6th prior.
 

KTMasean

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Well, the exhaust will not limit revs only in certain gears so I would have another chat with your Orlando chap.
If all was well before the installation of the EVO the easiest way to test this will be to install the Dimsport dongle.
 

owspeed

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I have a 2018 RC390 with a full Mivv exhaust and Rapid Bike Evo installed. The engine seems to run smoothly and pulls great in 1st-4th gears; however, in 5th and 6th gears it won't rev past approximately 8500 rpm and will now only hit an indicated top speed of about 85 mph. Any thoughts on what may be causing this? A tech at Rapid Bike told me they didn't think it was related to the Rapid Bike as it doesn't utilize any gear sensor information.
Do you have intake/air box work?

I had a similar situation, found the computer dongle plug was sitting in the air box intake mouth. In higher gears would just feel strangled. Once I move it would spin to redline again, but showed the need for more open free flowing intake. I removed the entire intake snorkel, air box lid and free flowing lid and filter. Revs vastly better!
 
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