Acceleration - Honda Rebel Forum
Reply
 
Thread Tools Display Modes
post #1 of 16 Old 09-17-2019, 07:57 PM Thread Starter
 
Sparker's Avatar
 
Join Date: Aug 2019
Posts: 21
Acceleration

Hey guys, don’t know if I’m on the right form. I don’t know if this is or isn’t normal but I can’t my 1999 Honda Rebel over 40-45mph. I feel like I’m pushing it at that speed. I thought maybe because it’s an older bike?
Sparker is offline  
Sponsored Links
Advertisement
 
post #2 of 16 Old 09-17-2019, 08:24 PM
 
SoakedKarma's Avatar
 
Join Date: Jun 2014
Location: Nevada
Posts: 1,396
When was the last time you changed your air filter?
take for a short quick ride without filter..
my 87 will do 75mph no problems.. sounds like it's going to explode from rpm..
air cooled Honda's like high rpm

96 VS800 Intruder (sold 2018 ), 87 CMX250C Rebel,
79 CB400 Hawk (sold 93), 75 CB350 (sold 83), 71 CB350 (stolen 74)
Help others help you, Include Year in your signature...
SoakedKarma is offline  
post #3 of 16 Old 09-17-2019, 10:39 PM Thread Starter
 
Sparker's Avatar
 
Join Date: Aug 2019
Posts: 21
Quote:
Originally Posted by SoakedKarma View Post
When was the last time you changed your air filter?
take for a short quick ride without filter..
my 87 will do 75mph no problems.. sounds like it's going to explode from rpm..
air cooled Honda's like high rpm
Not gonna lie I didn’t know it had one. I changed the oil but I must be blind. I haven’t seen an air filter on my 1999. Where is it at?
Sparker is offline  
 
post #4 of 16 Old 09-17-2019, 10:57 PM
Moderator
 
Join Date: Aug 2008
Location: Monroe, Louisiana
Posts: 28,202
Here's a diagram of the filter and housing. It's located behind the plastic left side cover. https://www.cheapcycleparts.com/oemp...2e/air-cleaner

Keepin' all the left over parts. Gonna use 'em to build another bike!

'01 & '09 Rebel 250, '06 Ninja 250, '89 VN 750
Putting your bike year and model in your signature helps others help you!
Here's how: https://www.hondarebelforum.com/f19/...re-121087.html
flitecontrol is offline  
post #5 of 16 Old 09-18-2019, 08:19 AM
 
7milesout's Avatar
 
Join Date: Jun 2019
Posts: 163
Garage
Sounds like another case of the no good diaphragm on the carburetor's vacuum piston.


Sparker, looks like these carburetors have a (rubber / rubberish) diaphragm that deteriorates over time and doesn't seal properly. And when that happens, it doesn't allow enough pressure difference on either side of the diaphragm to cause the vacuum piston to slide all the way up in the carburetor when needed. Therefore, the engine doesn't get as much airflow as is possible. In essence the airflow is choked off, but the air fuel ratio is good because that piston is also controlling the jet needle within the needle jet holder and main jet, so the bike runs good at it's new airflow limited speed.


That's what I'm guessing here...

2016 Honda Rebel 250 - The "Piglet."
AFR sensor equipped and downsized to a 0.105" main jet.
The only changes so far.
Bought on 6/29/19 with 44 miles.
7milesout is offline  
post #6 of 16 Old 09-18-2019, 02:03 PM
 
SoakedKarma's Avatar
 
Join Date: Jun 2014
Location: Nevada
Posts: 1,396
@7milesout could be correct.. Not knowing of any carb history anything is possible.

Specific instructions for vacuum piston assembly:

"Hold the vacuum piston up to almost full open so the diaphragm is not pinched by the chamber cover"
"Install the chamber cover with the spring, aligning it's tab with the hold in the carburetor, and secure with at least two screws before releasing the vacuum piston."

been negligent myself with this instruction..
but i would check the air filter first.
Attached Images
File Type: jpg 9-18-2019 10-43-25 AM.jpg (115.5 KB, 4 views)

96 VS800 Intruder (sold 2018 ), 87 CMX250C Rebel,
79 CB400 Hawk (sold 93), 75 CB350 (sold 83), 71 CB350 (stolen 74)
Help others help you, Include Year in your signature...
SoakedKarma is offline  
post #7 of 16 Old 09-19-2019, 10:10 PM Thread Starter
 
Sparker's Avatar
 
Join Date: Aug 2019
Posts: 21
Thanks guys. I just had the carburetor completely rebuilt. I'll check the air filter and let you guys know what I find. Probably will be a few days.
Sparker is offline  
post #8 of 16 Old 10-15-2019, 04:24 PM Thread Starter
 
Sparker's Avatar
 
Join Date: Aug 2019
Posts: 21
Valves and Air filter

I’m back! Okay, so air filter was replaced but I haven’t adjusted the valves (a link was provided). That’s not the issue atm. After I do adjust the valves, what else could be causing my Rebel 250 to only be going at 45mph? It will go any faster and I’m in the highest gear and still nothing. I feel like there’s such short times between changing gears and then I’m at the highest. Help meh please! Should I do a video as well?
Sparker is offline  
post #9 of 16 Old 10-15-2019, 04:34 PM
Moderator
 
Join Date: Aug 2008
Location: Monroe, Louisiana
Posts: 28,202
If the person who rebuilt the carb didn't notice any tears in the diaphragm, that doesn't mean there weren't any, and would explain your problem.

Please put your bike information in your signature so others will know what year and model you have. See my signature for how-to. I'm going to merge your latest thread with this one since it deals with the same issue.

Keepin' all the left over parts. Gonna use 'em to build another bike!

'01 & '09 Rebel 250, '06 Ninja 250, '89 VN 750
Putting your bike year and model in your signature helps others help you!
Here's how: https://www.hondarebelforum.com/f19/...re-121087.html
flitecontrol is offline  
post #10 of 16 Old 10-15-2019, 05:01 PM Thread Starter
 
Sparker's Avatar
 
Join Date: Aug 2019
Posts: 21
Do ya mean adding in a message when I type it as the signature? Just making sure. And thank you. So they rebuilt the carb but the diaphragm could be torn? Forgive me, I'm not familiar with the terminology. Do you have a photo I could see for reference?
Sparker 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: 2 (0 members and 2 guests)
 



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