R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 05-26-2008, 06:08 PM   #1
Tech Initiate
 
kn0bbyba11's Avatar
 
Join Date: May 2008
Posts: 21
Default brake problems

my brother's buggy keeps shutting off everytime he puts the brakes on, what is causing this and what can he do to fix it?
kn0bbyba11 is offline   Reply With Quote
Old 05-26-2008, 06:13 PM   #2
Tech Rookie
 
Join Date: May 2008
Location: LA
Posts: 16
Default

iim having brake problems also

when i hit the brakes they dont grab as tight as they used to so im getting a new oair of disc brakes
IWannaGoFast2 is offline   Reply With Quote
Old 05-26-2008, 06:14 PM   #3
Tech Addict
 
Powerlink's Avatar
R/C Tech Elite Subscriber
 
Join Date: Dec 2007
Location: so Cal.
Posts: 603
Send a message via AIM to Powerlink
Default

It would help if could tell us what make and model the buggy was there might be some people here with the same buggy .Most buggys are the same I know but it would help
__________________
Karl Rolf
Powerlink is offline   Reply With Quote
Old 05-26-2008, 06:14 PM   #4
Tech Master
 
jpz_67's Avatar
 
Join Date: Jul 2006
Location: Texas.
Posts: 1,787
Trader Rating: 56 (100%+)
Default

This should be a simple fix. It sounds as if you have the idle gap on your engines carburetor set to small. Somewhere on the carb, usually at the base on the front, there is a screw that controls the idle gap. Turn the screw in to increase the gap along with idle speed, and if you turn the screw out you get the opposite effect. Hope this helps.
__________________
Agama A215, Futaba, Nitro Pro Fuel, Proline tires, Triton Engines, Savox.
jpz_67 is offline   Reply With Quote
Old 05-26-2008, 06:19 PM   #5
Tech Initiate
 
kn0bbyba11's Avatar
 
Join Date: May 2008
Posts: 21
Default

the buggy is an Exceed RC 1/10

I will tell him to try to find that idle screw, the only thing that confuses me is that it is only recently, after his suspension arm broke, that he has been having troubles with the buggy
kn0bbyba11 is offline   Reply With Quote
Old 05-26-2008, 06:24 PM   #6
Tech Addict
 
Powerlink's Avatar
R/C Tech Elite Subscriber
 
Join Date: Dec 2007
Location: so Cal.
Posts: 603
Send a message via AIM to Powerlink
Default

Quote:
Originally Posted by kn0bbyba11 View Post
the buggy is an Exceed RC 1/10

I will tell him to try to find that idle screw, the only thing that confuses me is that it is only recently, after his suspension arm broke, that he has been having troubles with the buggy
So this is a 1/10th nitro two wheel drive ?
__________________
Karl Rolf
Powerlink is offline   Reply With Quote
Old 05-26-2008, 06:26 PM   #7
Tech Initiate
 
kn0bbyba11's Avatar
 
Join Date: May 2008
Posts: 21
Default

no it is 4wd im sorry
kn0bbyba11 is offline   Reply With Quote
Old 05-26-2008, 06:47 PM   #8
Tech Initiate
 
kn0bbyba11's Avatar
 
Join Date: May 2008
Posts: 21
Default

Quote:
This should be a simple fix. It sounds as if you have the idle gap on your engines carburetor set to small. Somewhere on the carb, usually at the base on the front, there is a screw that controls the idle gap. Turn the screw in to increase the gap along with idle speed, and if you turn the screw out you get the opposite effect. Hope this helps.
he just tried what you suggested and it didn't help, it still shuts off when the brake is put on
kn0bbyba11 is offline   Reply With Quote
Old 05-26-2008, 06:56 PM   #9
Tech Adept
 
Join Date: Apr 2008
Posts: 208
Trader Rating: 2 (100%+)
Default

either he has adjusted the wrong screw or hasn't adjusted it enough.

tell him to take off the air filter, hold the throttle closed by finger. (just push on the slide where it normally opens up)

when holding the slide closed gently, adjust the idle speed screw and you should see the idle gap increasing. tell him to set the gap at 1mm at the widdest point..

then test it out

once the idle is set correctly you can then adjust the bottom end to stop over fueling and to give you a good clean take off with good power...
pracy is offline   Reply With Quote
Old 05-26-2008, 07:26 PM   #10
Tech Initiate
 
kn0bbyba11's Avatar
 
Join Date: May 2008
Posts: 21
Default

which screw is it that he should be adjusting, the idle mixture or idle adjusting screw

we don't see the gap you are talking about, the only gap we see is from the one that lets air into the carb and that doesn't move when the idle adjusting screw is turned

Last edited by kn0bbyba11; 05-26-2008 at 07:38 PM.
kn0bbyba11 is offline   Reply With Quote
Old 05-26-2008, 09:00 PM   #11
Tech Elite
 
tkhoo's Avatar
 
Join Date: Jun 2003
Location: Somewhere in Penang Island, Malaysia
Posts: 3,495
Trader Rating: 45 (98%+)
Send a message via MSN to tkhoo
Default

Quote:
Originally Posted by kn0bbyba11 View Post
which screw is it that he should be adjusting, the idle mixture or idle adjusting screw

we don't see the gap you are talking about, the only gap we see is from the one that lets air into the carb and that doesn't move when the idle adjusting screw is turned
Hi, refer to below link on the pic where the screw is located.

http://www.rbproducts.com/mainEn.php...0.12%20engines
__________________
1/8 scale buggy: HB D8, Truggy: 1/12 Jammin CRT.5
Radio: Sanwa M8 power by Sanyo Eneloop, Charger: Hot Power 6016
http://pgrcclub.blogspot.com/
tkhoo is offline   Reply With Quote
Old 05-26-2008, 09:03 PM   #12
Tech Master
 
Revo-lution's Avatar
 
Join Date: Apr 2008
Location: TN
Posts: 1,362
Trader Rating: 14 (100%+)
Default

Remember every time you make an adjustment to the idle screw, you retune the low end. They work together. If you raise the idle, richen the mixture. If you lower the idle, lean the mixture. It's a balancing act like a set of scales. Most people only do one or the other and that's why they can't get their engine to run worth a flip.

When starting to tune......... Generally you want to richen the low end a bit to where it seems reasonable, if it idles too high it can affect your overall temps. How it takes off means nothing when you start the tuning process.

Run the vehicle three hard full throttle passes of about 150 feet each and come back and temp the engine. It doesn't matter if it takes off slow, as long as it gets up to full speed and temps around 220 after three drag style runs. Adjust accordingly to hit that mark.

Once you are done with that, you want to make sure that when you apply the brakes that your idle screw is in enough to keep it from choking out. Then start adjusting your low end mixture. If the vehicle takes off slowly, lean the low end, BUT make sure to adjust the idle screw down if the car idles up higher than normal. Any time your engine idles up when you adjust the low end, you compensate by adjusting the idle screw down.

A lot of people adjust the idle screw for minimum gap and walk away...... there is absolutely no way to tune the low end under these circumstances. The idle screw is not there to keep your engine set at one idle point, it is there to keep your engine running depending on the LOW END mixture setting. Temps, humidity, elevation and several other factors effect this. There is no "one setting" on an idle screw. Most of the time when a engine revs up when you stop it generally is low needle is lean. If never idles down then it is idled to high.

Newb mistakes:

- tuning the high end for temps when the low end mixture is too lean and causing the problem.
- setting the idle screw by measurement rather than engine conditions
- tuning the low end mixture and not retuning the idle screw at the same time.

This will get your engine NEARLY perfect, but once you have this as a base setting you can make minor changes that affect performance without fearing the temps. Between 220 and 260 don't tune for temp, tune for performance, but be weary of going over 260 as there are limitations of the components that make up the engine above 260.
__________________
~ Go big or go home ~
~ Novarossi powered 8T 1.0 - A.K.A. 4.0~

Last edited by Revo-lution; 05-27-2008 at 06:18 AM.
Revo-lution is offline   Reply With Quote
Old 05-26-2008, 09:13 PM   #13
Tech Lord
 
UN4RACING's Avatar
 
Join Date: Oct 2006
Location: MODIFIED!
Posts: 13,140
Trader Rating: 22 (100%+)
Default

Sounds like a bad clutch bell bearing to me?
UN4RACING is offline   Reply With Quote
Old 05-26-2008, 09:31 PM   #14
Tech Master
 
Revo-lution's Avatar
 
Join Date: Apr 2008
Location: TN
Posts: 1,362
Trader Rating: 14 (100%+)
Default

Clutch does not affect brake. If it idles without the brake the clutch is already spinning at about the same RPM or within a reasonably close range. if closing the carb causes the problem, it's an easy pinpoint.
__________________
~ Go big or go home ~
~ Novarossi powered 8T 1.0 - A.K.A. 4.0~
Revo-lution is offline   Reply With Quote
Old 05-27-2008, 08:11 AM   #15
Tech Adept
 
kevinmajor's Avatar
 
Join Date: May 2007
Posts: 192
Trader Rating: 3 (100%+)
Default

A broken clutch shoe spring will do the same thing. The clutch is always engaged, so when you hit the brakes it stops the rotation of the crank shaft and kills the engine.
kevinmajor is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
3PK Super Brake servo problems nitrofarm Wisconsin & Illinois Racing 9 04-30-2008 01:49 PM
HELP - How to BRAKE - IN savage600 Indonesia Racing 47 08-01-2006 05:22 AM
ECS- Auto brake/Neutral Brake/Drag brake RC12L3a Electric On-Road 6 11-21-2004 09:10 PM
brake SUper nitro dud Minnesota and North/South Dakota Racing 6 09-10-2004 03:01 PM
drag brake, brake and reverse imjonah Rookie Zone 3 07-24-2004 06:20 PM



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

Advanced Search

Posting Rules
You may not post new threads
You may not 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 On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 02:06 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net