I have always been rideing v-twins and I just bought a 89 cbr600f,so i have a few questions.

1) While in 6th gear at 55mph i'm pushing 4700rpm. Is this normal? Remember i'm used to a v-twin and 4700rpm means get ready to shift.

1.5) If that is the proper rpm in 6th at 55, what size sprockets can i get to lower the rpm and use the stock chain that was just put on?

2) My bike has a super trapp muffler on it with 8 removeable disc. Well i don't know if this is a good muffler or if it belongs on the bike because the engine will fall on it's face at about 5200rpm and come back to life twice as strong at about 5700. Although it sounds great, it isn't smooth. Does the muffler need adjusted or replaced? I was told the bike has been jetted.

 

Yes, well seeing how you have a 12,000 rpm redline, 4700 rpm at 55mph actually sounds about right. Why do you want to lower the rpm? Are you commuting on it? It is a sportbike and was meant to be ran at high rpm. You really don't get into the good powerband until 8 or 9000 rpm anyway. That muffler and the supposedly jetted carb are related. It is my understanding that the number of discs will alter the midrange powerband. ( don't quote me on that because I'm not 100% sure. ) There are others on this forum with better knowledge than me. OEM sprocket sizes are 15 front and 44 rear.
With stock gearing I was running 6th gear, 6000 rpm @ 75 mph. Good luck and welcome to the forum!

 

I would actually gear it down to get more grunt, its what I did ( and MANY other people have) and mine is now at about5krpm in 6th at 55mph. a LOT more grunt in the low, mid, and high end, just lose some top end. for me it was well worth it and I still get 55-57 mpg cruising around. no idea about the supertrapp exhaust, I have a v&h and it was on it when I got it. are your carbs good and clean?

 

i have a supertrapp on my 87 and always like the sound. you can read up on them here: http://www.supertrapp.com/resource/faqs.asp and buy more discs here:http://store.summitracing.com/egnsea...5&autoview=sku

 

Thanks. i just wanted to make sure it was running in the right range and that someone befor me didn't change the gearing. i'm going to have me mech take a look at the carbs this weekend.

I don't want to gear it down cause it has no problem standing up in 2nd already. i mostly ride 15 mile to and from work, 10 of them on smooth straightaways where the posted 55 can easily be forgotten!

Thanks for the links!

 

wow, I cant get mine to wheelie and I feel I have it jetted really well and it is geared down, modded airbox with kn filter, and timing advance! nice that yours will!!