Honda CBR 300 Forum banner

1 - 14 of 14 Posts

·
Premium Member
Joined
·
5,384 Posts
Discussion Starter #1 (Edited)
I picked up my new 300 on Friday and after a long 500km run home to evaluate and run in the engine a bit I was ready to slip on the Delkevic carbon muffler I had on my CBR250. (despite the press blurb the new muffler still sounds like a cross between a leaf blower and a farm quad bike)
But alas they have lengthened the header pipe by about 100mm so its not a straight forward fitting job.
Unless you can find a shorter linking pipe with the right angles (unlikely) the easiest way around it is to cut the pipe shorter using a cutting disc in an angle grinder. Sounds like a harsh thing to do to a new bike but it worked and you can do it with the header pipe on the bike (make sure you angle the sparks in the direction of the floor) as this holds the pipe firm for you while you cut it. Remove the right hand lower belly fairing first tho.

I love the extra passing power of the 300 but it's not as smooth as my 250 engine was. Once I get to 6000rpm an annoying vibration sets in through the pegs, seat and bars to a lesser extent. Unless I just got a badly balanced motor perhaps. Would be keen to hear other peoples thoughts who have owned both engine sizes.
 

·
Registered
Joined
·
162 Posts
Would love to see a picture of what you've done with the exhaust. I would be afraid to start cutting things off of my bike, but maybe that's just because I haven't looked into it much at the moment.

I would probably just go with an exhaust that is made specifically for the CBR300. Seems easier, but its good to have this info here for people who have a CBR250.
 

·
Registered
Joined
·
149 Posts
Would love to see a picture of what you've done with the exhaust. I would be afraid to start cutting things off of my bike, but maybe that's just because I haven't looked into it much at the moment.

I would probably just go with an exhaust that is made specifically for the CBR300. Seems easier, but its good to have this info here for people who have a CBR250.
Same. Would love to see pics. Problem with getting cbr300 specific parts is just that there really aren't that many out at the moment.
 

·
Premium Member
Joined
·
5,384 Posts
Discussion Starter #6 (Edited)
Just the same after fitting the Delkevic but it sounds heaps better and with the k & N air filter it snaps off the mark real smartly when given a burst of throttle.
I wasn't particularly surprised that the 300 had more vibes than the 250 as its a stroked version of an existing design rather than a motor designed with a clean sheet of paper. A longer stroke equals a higher physical force to be counter balanced etc.

Its not unbearable tho or worth going to the dealer about, just an observation and I'm sure if you bought the bike without having owned a CBR250 beforehand it would go mostly unnoticed. My 250 had a sweet motor that spun real nicely and loved to rev :)

Having said all of that, I read your posting about the breaking in procedure and even tho I've missed the 20 mile window i'm gonna go out tomorrow on a 200mile twisty road and give it ****!

Will try to upload a photo in next day or two, I think i have some notes saved on how to do it from Moto Mike or someone in the know.

Another observation on the 300 vs 250: Even tho it has a 36 tooth rear sprocket instead of a 38 it still reads exactly 6000rpm at 100kph (60mph) in top gear like the 250 did. So its really under geared IMO and I'm putting the 15 tooth front sprocket on tomorrow.
 

·
Registered
Joined
·
532 Posts
If I'm remembering correctly weren't there also some vibing issues with the 250 as well. Or was that a rattle instead???
 

·
Premium Member
Joined
·
5,384 Posts
Discussion Starter #8
Nope, no bad vibes with my 250, cant speak for others tho. You could sit on 80MPH hour pretty much vibe free even tho it was sure revvin.
 

·
Registered
Joined
·
2 Posts
The vibrations on my CBR300R at 6000rpm seem to be more apparent after it's first service (@1000kms) - any thoughts on why this might be?

I have only been riding for a month (so forgive me if this seems odd) but it was significant enough for me to notice on my first ride after the service.
 

·
Premium Member
Joined
·
5,384 Posts
Discussion Starter #11
The vibrations on my CBR300R at 6000rpm seem to be more apparent after it's first service (@1000kms) - any thoughts on why this might be?
Hello fellow Kiwi! I have no idea why you got a delayed reaction on your vibes, possibly a loosening up in the bore after 1000km. Generally they don't actually do anything to the motor at its first service apart from change the oil and filter which wouldn't make any difference I'd think. The valve clearances rarely need adjusted after 1000km on a modern bike according to my local dealer.
Glad I'm not the only one who has a tingly bike!
 

·
Registered
Joined
·
204 Posts
The vibrations on my CBR300R at 6000rpm seem to be more apparent after it's first service (@1000kms) - any thoughts on why this might be?

I have only been riding for a month (so forgive me if this seems odd) but it was significant enough for me to notice on my first ride after the service.
If you can hear any odd noises at idle from the head, you might want to get the shims checked. Otherwise, just put on another 3000 miles and the vibes will subside.
 

·
Registered
Joined
·
2 Posts
Hello fellow Kiwi! I have no idea why you got a delayed reaction on your vibes, possibly a loosening up in the bore after 1000km. Generally they don't actually do anything to the motor at its first service apart from change the oil and filter which wouldn't make any difference I'd think. The valve clearances rarely need adjusted after 1000km on a modern bike according to my local dealer.
Glad I'm not the only one who has a tingly bike!
Thanks for the reply. Didn't think it would be related to the service but had to ask. Did you fit the 15 tooth sprocket on the front? If so, was there any reduction in the vibrations?
 

·
Premium Member
Joined
·
5,384 Posts
Discussion Starter #14
Thanks for the reply. Didn't think it would be related to the service but had to ask. Did you fit the 15 tooth sprocket on the front? If so, was there any reduction in the vibrations?
Yes on the front, they are a cheap sprocket to buy in NZ as they are the same as the ones on the XR250 trail bikes which are as common as out here. Less than $20.
Yes it helps reduce vibes as the engine is revving less at the same speed and under slightly more load which seems to help.
 
1 - 14 of 14 Posts
Top