Total noob, 2008 Rebel 250, acceleration issues, misfiring? - Honda Rebel Forum
Reply
 
Thread Tools Display Modes
post #1 of 37 Old 10-02-2019, 04:41 PM Thread Starter
 
Join Date: Oct 2019
Posts: 15
Total noob, 2008 Rebel 250, acceleration issues, misfiring?

*sorry for the essay, wasn't sure what was important to say*
Hello everyone, I'm new to the forum and new to riding in general. I bought a used 2008 Honda Rebel 250. Allegedly the first owner bought it, rode it and then garaged it for 8 years. She then polished it up, got it riding and sold it to a guy who rode it for 3 months with the choke on (also a noob, and wanted to use the rebel to learn to ride, he got to top speed 75 mph), but then he outgrew it and sold it to me.

I've had a lot of help working on this bike from people more motorcycle inclined/a mechanic who came by to change the tires and oil. I really don't have the means to spend any more on a diagnosis for the mechanic to come back so I'm hoping any of you fine people might be able to point me in the right direction to look in the manual or anything. Before he left, he said it might be the carburetor float (which we sent a picture to him and he said it was fine although it wasn't level). He also said it definitely wasn't the engine because he was able to rev really high.

So far since I've brought it home, the carb has been cleaned out twice (first go around something got clogged because this was before I'd changed the oil and gas... who knows how long the regular gas was sitting in there...), valves adjusted to .003mm (opened the top and the crank case to spin), oil changed, new air filter installed, new tires, new headlight, new gas (Premium), new spark plugs.

The bike idles really nicely and shifts well too. Due to the problems it's only been ridden down a side street and back a few times. The problems I'm seeing now:

-Anytime I roll the throttle (in gear or neutral), it misfires a little bit out of the exhaust. But this has decreased a lot since I've tuned the carb fuel screw and idle adjust (the black knob). Still does it a little though...

-It won't accelerate past 42 mph, even in a slight decline street full-throttle, 4th gear

-Before any work was done, when I slowly let the clutch out there was more power than there is now. Now, I have to give it some throttle to get up the driveway when before I could start from a stop at the sidewalk and just let the clutch out a little to get up the driveway. That might go along with the speed being so slow.

That's basically all the information I have right now... any help would be MUCH appreciated! Hopefully it's not a lost cause...
rebel250jane is offline  
Sponsored Links
Advertisement
 
post #2 of 37 Old 10-02-2019, 08:03 PM
Moderator
 
01-7700's Avatar
 
Join Date: Oct 2011
Location: Maine
Posts: 3,343
Garage
Sounds like classic dirty carb issues.

1985 Rebel 250 ... 2005 Ruckus 50
Keith from Maine USA - Banning Spammers since 2016
01-7700 is offline  
post #3 of 37 Old 10-02-2019, 08:11 PM
 
Join Date: May 2018
Posts: 78
Garage
Quote:
Originally Posted by rebel250jane View Post
*sorry for the essay, wasn't sure what was important to say*
Hello everyone, I'm new to the forum and new to riding in general. I bought a used 2008 Honda Rebel 250. Allegedly the first owner bought it, rode it and then garaged it for 8 years. She then polished it up, got it riding and sold it to a guy who rode it for 3 months with the choke on (also a noob, and wanted to use the rebel to learn to ride, he got to top speed 75 mph), but then he outgrew it and sold it to me.

I've had a lot of help working on this bike from people more motorcycle inclined/a mechanic who came by to change the tires and oil. I really don't have the means to spend any more on a diagnosis for the mechanic to come back so I'm hoping any of you fine people might be able to point me in the right direction to look in the manual or anything. Before he left, he said it might be the carburetor float (which we sent a picture to him and he said it was fine although it wasn't level). He also said it definitely wasn't the engine because he was able to rev really high.

So far since I've brought it home, the carb has been cleaned out twice (first go around something got clogged because this was before I'd changed the oil and gas... who knows how long the regular gas was sitting in there...), valves adjusted to .003mm (opened the top and the crank case to spin), oil changed, new air filter installed, new tires, new headlight, new gas (Premium), new spark plugs.

The bike idles really nicely and shifts well too. Due to the problems it's only been ridden down a side street and back a few times. The problems I'm seeing now:

-Anytime I roll the throttle (in gear or neutral), it misfires a little bit out of the exhaust. But this has decreased a lot since I've tuned the carb fuel screw and idle adjust (the black knob). Still does it a little though...

-It won't accelerate past 42 mph, even in a slight decline street full-throttle, 4th gear

-Before any work was done, when I slowly let the clutch out there was more power than there is now. Now, I have to give it some throttle to get up the driveway when before I could start from a stop at the sidewalk and just let the clutch out a little to get up the driveway. That might go along with the speed being so slow.

That's basically all the information I have right now... any help would be MUCH appreciated! Hopefully it's not a lost cause...
get berrymans chemdip at local autoparts store, download pdf of manual, completely disassembly carb (removing anything rubber or plastic), soak body for 24 hrs, soak bowl and acc. pump assembly for 24 hrs. add an inline fuel filter, reassemble and report back. id also replace the air filter if it was stored a while (mine had a small mouse nest in it )

2002 Honda Rebel 250
1981 Kawasaki KM100
1986 Honda Rebel 450
Daren4ch is offline  
 
post #4 of 37 Old 10-02-2019, 08:43 PM
Moderator
 
Join Date: Aug 2008
Location: Monroe, Louisiana
Posts: 28,158
Welcome to the forum. The folks here are very good at long distance diagnosis.

The Rebel does fine with 87 octane gas. Premium gas is for high compression engines, and the Rebel's isn't high compression. Suggest you install an inline fuel filter to keep contaminants from reaching the carb. https://www.hondarebelforum.com/f39/...ter-13278.html

Changing the oil is very easy with some basic tools. What brand and weight of oil did you use? It holds 1.6 quarts of oil, and the level is checked with the bike level (not on the side stand) and the dipstick unscrewed and resting on the threads.
Because the Rebel is air cooled and has no oil filter, most forum members change it every 1,000 to 1,500 miles. https://www.hondarebelforum.com/f39/...ide-11891.html

The easiest way to check the valves is explained here: https://www.hondarebelforum.com/f39/...ent-33874.html

Over 90% of the time, when the engine doesn't run properly, it's due to a dirty carb. If the previous owner had to use the choke, to get to 75 mph, the carb was/is dirty. The best way to clean a carb is in an ultrasonic cleaner, and the next best is soaking only the metal parts in Berrymans Chem Dip for 2-7 days. Chem Dip will destroy rubber and plastic. There are rubber O-rings on the air/fuel adjustment and carb drain screws. There is also a rubber carb bowl gasket, needle slide diaphragm and the float valve has a rubber tip. There are plastic parts on the throttle linkage. Carb spray is ineffective in getting out stubborn deposits in the internal passages.

Does the bike appear to accelerate normally in the lower gears? What happens if you shift into fifth at maximum rps?

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 37 Old 10-02-2019, 10:23 PM Thread Starter
 
Join Date: Oct 2019
Posts: 15
Quote:
Originally Posted by Daren4ch View Post
get berrymans chemdip at local autoparts store, download pdf of manual, completely disassembly carb (removing anything rubber or plastic), soak body for 24 hrs, soak bowl and acc. pump assembly for 24 hrs. add an inline fuel filter, reassemble and report back. id also replace the air filter if it was stored a while (mine had a small mouse nest in it )
I completely disassembled and reassembled the carb twice with a kit. Also sprayed cleaner through each of the holes to make sure there were no clogs. Will definitely look into the inline fuel filter. Just replaced the air filter with a brand new one
rebel250jane is offline  
post #6 of 37 Old 10-02-2019, 10:41 PM Thread Starter
 
Join Date: Oct 2019
Posts: 15
Quote:
Originally Posted by flitecontrol View Post
Welcome to the forum. The folks here are very good at long distance diagnosis.

The Rebel does fine with 87 octane gas. Premium gas is for high compression engines, and the Rebel's isn't high compression. Suggest you install an inline fuel filter to keep contaminants from reaching the carb. https://www.hondarebelforum.com/f39/...ter-13278.html

Changing the oil is very easy with some basic tools. What brand and weight of oil did you use? It holds 1.6 quarts of oil, and the level is checked with the bike level (not on the side stand) and the dipstick unscrewed and resting on the threads.
Because the Rebel is air cooled and has no oil filter, most forum members change it every 1,000 to 1,500 miles. https://www.hondarebelforum.com/f39/...ide-11891.html

The easiest way to check the valves is explained here: https://www.hondarebelforum.com/f39/...ent-33874.html

Over 90% of the time, when the engine doesn't run properly, it's due to a dirty carb. If the previous owner had to use the choke, to get to 75 mph, the carb was/is dirty. The best way to clean a carb is in an ultrasonic cleaner, and the next best is soaking only the metal parts in Berrymans Chem Dip for 2-7 days. Chem Dip will destroy rubber and plastic. There are rubber O-rings on the air/fuel adjustment and carb drain screws. There is also a rubber carb bowl gasket, needle slide diaphragm and the float valve has a rubber tip. There are plastic parts on the throttle linkage. Carb spray is ineffective in getting out stubborn deposits in the internal passages.

Does the bike appear to accelerate normally in the lower gears? What happens if you shift into fifth at maximum rps?

I appreciate your answer!!

I read somewhere in the manual that 87 or higher does the trick. Does Premium gas hurt it? Or just a waste of money?

Thanks, I'm probably going to order one of those inline fuel filters you guys are suggesting.

I'm not sure about the oil, the mechanic changed the oil and tires last week though. On his way out, he revved the engine pretty high and said if I hadn't done the valves correctly it wouldn't have sounded the way it did or have gotten that high? He seemed to think that the acceleration issue lied with the carb float level, but the next day when we texted him over pictures of the level he said it wasn't that.. although I'm not 100% because I've seen videos and everyone else's float pivots up and down from a standard level and mine's standard level starts at a down position.

Hoping that maybe we just didn't clean the carb right or something happened, but we used a carb kit and also brake cleaner to shoot through the little holes to clean it. It's pretty sparkly clean, we cleaned it two times last week because the first time wasn't a success (something got caught in the main jet I think it's called).

So it seems like it gets up easy on flat ground or downhill up to 3rd. But on flat the highest it can go is 3rd gear full throttle maybe 32-34 mph. The only time it got into 4th gear was going on a slight hill decline and the max speed was I think 44 mph full-throttle. My fiancee is the one who rode it she said it wouldn't go fast enough to get into 5th so I'm not sure how that gear is doing....could it be a clutch thing?

Considering opening the carb up again though after your guys' answers...third time might be the charm...
rebel250jane is offline  
post #7 of 37 Old 10-02-2019, 10:43 PM Thread Starter
 
Join Date: Oct 2019
Posts: 15
Quote:
Originally Posted by 01-7700 View Post
Sounds like classic dirty carb issues.
Hi, thanks! I hope it'll end up being a problem that simple. Might check a few things first and then get that chem dip everyone mentioned.
rebel250jane is offline  
post #8 of 37 Old 10-02-2019, 11:11 PM
 
SoakedKarma's Avatar
 
Join Date: Jun 2014
Location: Nevada
Posts: 1,379
Vacuum piston should be held in open position as top cover screws tightened..
assures proper sealing of edge seal..
I assume you checked the vacuum piston rubber diaphragm for tears..

There is an O embossed on top cover that should align above diaphragm tab..

a leak in seal or through tear will could cause condition described..
Attached Images
File Type: jpg 9-18-2019 10-43-25 AM.jpg (115.5 KB, 3 views)
File Type: jpg CarbTop.jpg (236.3 KB, 2 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 online now  
post #9 of 37 Old 10-02-2019, 11:23 PM Thread Starter
 
Join Date: Oct 2019
Posts: 15
Quote:
Originally Posted by SoakedKarma View Post
Vacuum piston should be held in open position as top cover screws tightened..
assures proper sealing of edge seal..
I assume you checked the vacuum piston rubber diaphragm for tears..

There is an O embossed on top cover that should align above diaphragm tab..

a leak in seal or through tear will could cause condition described..
Thanks for the input, I'm thinking about just triple checking the carb tomorrow and soaking it in the chem dip while it's out.
rebel250jane is offline  
post #10 of 37 Old 10-02-2019, 11:53 PM Thread Starter
 
Join Date: Oct 2019
Posts: 15
So a quick update if anyone is still following or if anyone new sees this, I did the spit-on-the-exhaust-while-it's-hot test. Figured out that the left side exhaust (the one that the misfire noise comes out of) isn't getting that hot. After about 15 minutes of riding around my street/idling, I splashed some water on the right side exhaust pipe and it immediately sizzled/steamed. Then I went over to the left side and splashed some water and it didn't evaporate for a few minutes. Heard about the test, but not exactly sure what the results mean?
rebel250jane 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: 10 (1 members and 9 guests)
markwilliamson
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