Runs rough at 4500rpm... - Wrist Twisters
 
Thread Tools Display Modes
post #1 of 8 Old 03-11-2015, 10:56 PM Thread Starter
Pete
 
SVCBNZ's Avatar
 
Join Date: Aug 2014
Location: Auckland
Posts: 13
Rep Power: 1
 
Runs rough at 4500rpm...

My hornet has always run somewhat rough at around 4500rpm when not accelerating. Under load she vibrates alot more in that rev range, which unfortunately is what I like to cruise at ideally. However at around 6000rpm shes as smooth as silk.

Is this normal, otherwise what can be done about it other than just riding in a lower gear?

I am considering dropping a tooth on my front sprocket down to 16, has anyone also done this? By the looks of it, I should be able to keep my current chain and rear sprocket...

SVCBNZ is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 03-12-2015, 04:22 AM
Cornicen
 
crimedog's Avatar
 
Join Date: Sep 2013
Location: West of Boston
Posts: 511
Rep Power: 1
 
Yes, that's normal for this engine. If I were you I would ride that chain into the ground and then buy a 520 17/44 kit from LDH. Down a front tooth with this bike would be great if you are a stunter but terrible for regular use.

08 DR-Z400SM
WFOATT
crimedog is offline  
post #3 of 8 Old 03-12-2015, 04:28 AM
Tirone Choolaces
 
marylandmike's Avatar
 
Join Date: Aug 2007
Location: USA
Posts: 11,180
Rep Power: 1
 
Garage

Awards Showcase
Wrist Twisters Event Attendance Donation Donation 
Total Awards: 3

OEM front sprocket is 16. You can lower the cruising RPM by going up on tooth in the front. Popular combo for the 919 is 17 front/ 44 rear, which I run and really like.

As far as the vibes at 4,500 RPM, you may want to check for a cracked exhaust mount under the bike.

marylandmike is offline  
 
post #4 of 8 Old 03-16-2015, 06:50 PM Thread Starter
Pete
 
SVCBNZ's Avatar
 
Join Date: Aug 2014
Location: Auckland
Posts: 13
Rep Power: 1
 
What sort of performance does the 17/44 give over stock?
Il have a look into the exhaust mount, thanks for the help!

SVCBNZ is offline  
post #5 of 8 Old 03-16-2015, 07:33 PM
Cornicen
 
crimedog's Avatar
 
Join Date: Sep 2013
Location: West of Boston
Posts: 511
Rep Power: 1
 
Quote:
Originally Posted by SVCBNZ View Post
What sort of performance does the 17/44 give over stock?
Il have a look into the exhaust mount, thanks for the help!
It increases the gearing from stock, there is no change in performance. This engine has such great torque that it can pull through taller gearing with ease, so you end up shifting less and cruising on the highway at a lower rpm.

08 DR-Z400SM
WFOATT
crimedog is offline  
post #6 of 8 Old 03-16-2015, 07:36 PM Thread Starter
Pete
 
SVCBNZ's Avatar
 
Join Date: Aug 2014
Location: Auckland
Posts: 13
Rep Power: 1
 
IMPRESSIVE! Thank you marylandmike.... indeed the exhaust mount was broken... will get it welded and report back if that cured the vibrations

SVCBNZ is offline  
post #7 of 8 Old 03-16-2015, 08:04 PM
Tirone Choolaces
 
marylandmike's Avatar
 
Join Date: Aug 2007
Location: USA
Posts: 11,180
Rep Power: 1
 
Garage

Awards Showcase
Wrist Twisters Event Attendance Donation Donation 
Total Awards: 3

Quote:
Originally Posted by SVCBNZ View Post
IMPRESSIVE! Thank you marylandmike.... indeed the exhaust mount was broken... will get it welded and report back if that cured the vibrations
Glad you found it....just seen several here before that had the issue.

marylandmike is offline  
post #8 of 8 Old 03-16-2015, 08:06 PM
Why's everything on fire?
 
CB700S's Avatar
 
Join Date: Mar 2011
Location: Dallas
Posts: 2,361
Rep Power: 1
 
Garage
Quote:
Originally Posted by SVCBNZ View Post
IMPRESSIVE! Thank you marylandmike.... indeed the exhaust mount was broken... will get it welded and report back if that cured the vibrations
Welding it may not do much, it may crack again. There are members here that make reinforcement/repair plates that can be bolted to the broken pieces as a permanent fix.

1986 Honda Nighthawk 700S
2002 Honda 919
CB700S is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Wrist Twisters forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome