450 carb questions - Honda Rebel Forum
Reply
 
Thread Tools Display Modes
post #1 of 15 Old 06-15-2019, 02:41 PM Thread Starter
 
Join Date: May 2019
Posts: 61
450 carb questions

My 450 seems to be lacking a little power today, unless it's my imagination. Even in 5th gear the engine sounds like it's struggling around 40mph, or does this sound normal for these bikes?


Hard to know as I've only had it a couple of weeks and ridden just a couple of times so far.


I popped out the air filter, expected to hear the sound of air being pulled into the carbs, but nothing. Again, is this normal for these bikes?


It does drive a little ****ty when the choke is on, still trying to find a routine of getting the choke right until I can turn off the choke off completely.


When the choke is on should it increase the idle speed, or does it simply enrich the fuel intake only?


I do get a bit of popping occasionally but as it's an old bike I just accept it for what it is!


Thoughts anyone.


Thank you.

--------
1986 Rebel 450, a little bit bobbed here and there!
maritimesbob is offline  
Sponsored Links
Advertisement
 
post #2 of 15 Old 06-15-2019, 10:22 PM
Moderator
 
wjmrty's Avatar
 
Join Date: Feb 2011
Location: Melbourne,Victoria. Australia
Posts: 7,654
Garage
It sounds like your carbs need a clean. From 40mph it should pull strong in 5th gear. When choke is on it will raise the idle speed



2000 rebel 250 Aussie My Baby.
2012 honda PSX 150cc scooter [in Thailand]
1986 rebel Silver 450 Elvis

putting your bike info in your signature helps others help you !
wjmrty is offline  
post #3 of 15 Old 06-16-2019, 07:54 AM Thread Starter
 
Join Date: May 2019
Posts: 61
With choke on there is little if any change in idle speed, but it certainly enriches the fuel intake because I can smell it.


Yesterday it was almost like the choke was stuck on a little, you know that "holding back" kind of feeling. Is that possible?


Anyways, yes I think it's time to get the tank off and take off the carbs. These carbs are joined as one unit and need to be split?


Clean out bowls, floats, jets etc?


Not done this sort of thing in a long time. Last time was my old Ford with a twin webber carb way back in the 80s!!!

--------
1986 Rebel 450, a little bit bobbed here and there!
maritimesbob is offline  
 
post #4 of 15 Old 06-16-2019, 04:27 PM
 
Join Date: May 2018
Posts: 59
Garage
Quote:
Originally Posted by maritimesbob View Post
With choke on there is little if any change in idle speed, but it certainly enriches the fuel intake because I can smell it.


Yesterday it was almost like the choke was stuck on a little, you know that "holding back" kind of feeling. Is that possible?


Anyways, yes I think it's time to get the tank off and take off the carbs. These carbs are joined as one unit and need to be split?


Clean out bowls, floats, jets etc?


Not done this sort of thing in a long time. Last time was my old Ford with a twin webber carb way back in the 80s!!!
1. Take a ton of pictures
2. Take out vacuum cylinders from both carbs.
3. Take off bowls, remove floats and jets
4. Remove all hoses except the one going to the bridge between the carbs
5. Unscrew all the brackets and loosen the screws holding the bar between the chokes on each carb
6. Pull apart the two carbs... carefully
7. Remove the two bridges between the carbs
8. Take off the two covers for hoses on each carb (donít know whatís this is called or does but thereís one on each carb on the outer side)
9. Remove idle screws (make sure to get the spring and rubber seat aswell)
10. Remove cable bracket
11. Remove the choke from each carb
12. Unscrew the disc on the butterfly on each carb
13. Rotate the butterflies to open and pull the disc out on each carb
14. Pull out the bracket for the disc on each carb
15 You should now be ready to soak your carbs... the forum recommends Berrymans Chemdip for 24 hrs each carb.
16. Id recommend also cleaning the accelerator pump (the weird looking thing on one of the bowls)

Chime in if I missed anything...

2002 Honda Rebel 250
1981 Kawasaki KM100
1986 Honda Rebel 450
Daren4ch is offline  
post #5 of 15 Old 06-18-2019, 08:30 AM
 
kryton's Avatar
 
Join Date: Sep 2016
Location: Northern Virginia
Posts: 1,913
Garage
dual carb? sounds like one side is clogged up and needs cleaning.

2009 Honda Rebel 250; 2009 Honda Shadow 750 Spirit
"The bravest thing for me to do is admit when I am wrong" - unknown
HRF Answer #1 You should take the MSF Rider Course
HRF Answer #2 You need to clean your carburetor
HRF Answer #3 Sorry we assumed if you didn't say otherwise
kryton is offline  
post #6 of 15 Old 06-19-2019, 07:45 PM
DNC
 
DNC's Avatar
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 1,059
Garage
Quote:
Originally Posted by Daren4ch View Post
1. Take a ton of pictures
2. Take out vacuum cylinders from both carbs.
3. Take off bowls, remove floats and jets
4. Remove all hoses except the one going to the bridge between the carbs
5. Unscrew all the brackets and loosen the screws holding the bar between the chokes on each carb
6. Pull apart the two carbs... carefully
7. Remove the two bridges between the carbs
8. Take off the two covers for hoses on each carb (donít know whatís this is called or does but thereís one on each carb on the outer side)
9. Remove idle screws (make sure to get the spring and rubber seat aswell)
10. Remove cable bracket
11. Remove the choke from each carb
12. Unscrew the disc on the butterfly on each carb
13. Rotate the butterflies to open and pull the disc out on each carb
14. Pull out the bracket for the disc on each carb
15 You should now be ready to soak your carbs... the forum recommends Berrymans Chemdip for 24 hrs each carb.
16. Id recommend also cleaning the accelerator pump (the weird looking thing on one of the bowls)

Chime in if I missed anything...
Hi, I (don't do carbs so I) recommend:

Drain and remove carbs.
Allow fumes to disperse for a short while.
Seal in plastic
Seal in padded box
Send to Jacksrebels.com for Carb cleaning.
Check mail 1-2 weeks later, depending on shipping and service arrangement.
Receive carbs
Install and ride!

Forgive me, I am a being funny, but actually serious. JRW has a guy that does these in his sleep and has been as a service to Rebel owners for many years. Turnaround keeps the bike parked, but the result is worth it. He uses an ultrasonic cleaner and actually test them before returning. With the ability to immediately replace parts and 'guarantee' why wouldn't you? No, I am not an employee or on commission, but do know that he is a savior to the Rebel owner and a genuinely good guy.


Good luck

'86 CMX450 Gin-ba
'87 CMX450 Kuro
'86 CMX450 Tabo
'90 CB-1 Seishin
'86 CMX450 Uki
DNC is offline  
post #7 of 15 Old 06-30-2019, 04:22 AM Thread Starter
 
Join Date: May 2019
Posts: 61
Ok, I noitced looking from the rear. The left side muffler has a lot more exhaust pressure coming out of the pipe than the right side. Is this normal or indicative perhaps that the lesser side needs some carb attention or something else?


I do need to get these carbs looked at I think. I noticed when I put full choke on, there is no increase in idle speed, it only enriches the the mixture (can smell it from exhaust!).


I live in the Netherlands so Jacks is not really an option. Probably doesn't ship overseas and I don't really want to wait too long for shipping anyways.

--------
1986 Rebel 450, a little bit bobbed here and there!
maritimesbob is offline  
post #8 of 15 Old 07-02-2019, 07:52 AM
 
kryton's Avatar
 
Join Date: Sep 2016
Location: Northern Virginia
Posts: 1,913
Garage
Quote:
Originally Posted by maritimesbob View Post
Ok, I noitced looking from the rear. The left side muffler has a lot more exhaust pressure coming out of the pipe than the right side. Is this normal or indicative perhaps that the lesser side needs some carb attention or something else?
it indicates something, compression, valves, dual carbs in need of being sync'd, lean fuel mix on that side, etc.

2009 Honda Rebel 250; 2009 Honda Shadow 750 Spirit
"The bravest thing for me to do is admit when I am wrong" - unknown
HRF Answer #1 You should take the MSF Rider Course
HRF Answer #2 You need to clean your carburetor
HRF Answer #3 Sorry we assumed if you didn't say otherwise
kryton is offline  
post #9 of 15 Old 07-02-2019, 09:54 AM
Moderator
 
wjmrty's Avatar
 
Join Date: Feb 2011
Location: Melbourne,Victoria. Australia
Posts: 7,654
Garage
Do a compression test after you adjust valve clearances



2000 rebel 250 Aussie My Baby.
2012 honda PSX 150cc scooter [in Thailand]
1986 rebel Silver 450 Elvis

putting your bike info in your signature helps others help you !
wjmrty is offline  
post #10 of 15 Old 07-02-2019, 09:57 AM
Moderator
 
wjmrty's Avatar
 
Join Date: Feb 2011
Location: Melbourne,Victoria. Australia
Posts: 7,654
Garage
Check valve clearances then do compression test



2000 rebel 250 Aussie My Baby.
2012 honda PSX 150cc scooter [in Thailand]
1986 rebel Silver 450 Elvis

putting your bike info in your signature helps others help you !
wjmrty is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda Rebel Forum 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











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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