R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 07-18-2006, 03:53 AM   #1
Tech Rookie
 
Join Date: Apr 2006
Posts: 6
Default Hi all please can ya help wierd problem!

Hi all i have had my car a few months now but only been out on it a few times.

I had it tweaked by a model store owner for good performance and it worked fine

Now when i push the throttle hard the engine dies it can run at low revs but as soon as i push it down hard it conks out maybe to much fuel or too little?

Thanks

karl
karlmaddock is offline   Reply With Quote
Old 07-18-2006, 06:52 AM   #2
Tech Adept
 
aaalp's Avatar
 
Join Date: Jul 2005
Location: istanbul - turkey
Posts: 196
Send a message via ICQ to aaalp Send a message via MSN to aaalp Send a message via Yahoo to aaalp
Post

Sound like it's too rich on the High Speed Needle. Try to richen it a bit. I hope this information from Josh Cyrul helps you tune your engine:

Tuning Your Nitro Engine 101
Each day you arrive at a race track to race your nitro engine there are many variables that change: air temp, air pressure, humidity and even minor differences from one gallon of fuel to the next. These differences can really affect your engine's tune and overall performance. Here's my general routine that I go through to tune my engine to get the best starting point to work from given the variables for the day. This routine can also be used if you decided to change nitro content or even a pipe or manifold at the track.

To start, raise the idle by closing the idle needle about ¼ turn from where the engine ran last. This will keep the engine from flaming out when running through the routine. Next, it's to the starter box to fire up the engine. Make sure to “blip” the throttle a few times to warm the engine up to a reasonable temperature. Open the top end needle a full turn and then slowly open up the carburetor to full throttle. Once you are at full throttle continue to open the top end needle until it nearly flames out. If it does flame out just close the top end needle about ¼ turn so you can restart the engine and continue with the process. The idea behind this is that you are sending a large quantity of fuel through the carburetor with very open needles, thus flushing out any dirt, residue or after run products from the engine. From here, close the top end needle (carburetor still at full throttle) until the clutch starts to engage and the wheels will spin. We will come back to this needle to finish tuning the engine for racing.

Setting the bottom end correctly can not only improve throttle response and bottom end power but it can also increase the consistency and reliability of your engine. To set the bottom end you should listen to the idle speed of the engine. Pay attention if it speeds up or slows down over a 10-20 second time frame. If the idle speed increases then you should open the bottom end needle. On the contrary, if the speed decreases then you should close the bottom end needle. Once you have achieved an idle that stays constant for about 1 minute you can begin to open the idle needle, which will lower the engines idle speed. Open the needle until the engine flames out and then close the idle needle about 1/8 of a turn and restart the engine. Your engine should idle for 45+ seconds before the idle will slow enough to flame out. This should yield a very low and consistent idle speed that will give you better fuel mileage, lower engine temperature and better operation of your clutch.

After tuning the bottom end and idle we are now back to the top end. The top end is usually best set out on the race track, but here's a way to get it close on the bench. Open the carburetor to full throttle (never for more than 2-3 seconds before returning to idle) listening to achieve a nice, clean sound. Take your time with this, it will greatly affect the life of your engine!! Once the engine sounds good, you have to make sure it isn't too lean. For a long straight, hard braking and then hard acceleration to the next corner out on the race track this is the best way to simulate that cycle on the bench. Open the carburetor to full throttle for 2-3 seconds, close the carburetor for 2-3 seconds and then back to full throttle for 2-3 seconds. Your engine should rev as nice on the 2 nd blast as it did on the first. If the engine hesitates then it is too lean and you need to open the top end needle. Remember, it's always better to start a little too rich vs. too lean!!

This routine should get your engine ready for the track each day before you race. While you are driving your car around the track remember to listen to the engine. Watching the smoke from the engine's exhaust is ok, but a lot of times it doesn't always give you a consistent reading of your engines tune. Different fuel mixtures (different oils or oil percentages) don't always yield the same smoke so it's important to have another gauge such as throttle feel, sound, as well as a temperature probe are all good ways to gauge your engines performance. Be patient and have fun!!

Good Luck!!
Josh Cyrul
CEFX
aaalp is offline   Reply With Quote
Old 07-18-2006, 06:55 AM   #3
Tech Adept
 
aaalp's Avatar
 
Join Date: Jul 2005
Location: istanbul - turkey
Posts: 196
Send a message via ICQ to aaalp Send a message via MSN to aaalp Send a message via Yahoo to aaalp
Post

More tips here:
http://www.cefx.net/tips/
aaalp is offline   Reply With Quote
Old 07-18-2006, 06:56 AM   #4
Tech Rookie
 
Join Date: Oct 2005
Posts: 1
Default

GBag is offline   Reply With Quote
Old 07-18-2006, 07:43 AM   #5
Tech Rookie
 
Join Date: Apr 2006
Posts: 6
Default

Thanks alot mate i will give that a go. I think i may have a hole somewhere as when i pull the pull start i can here air excaping
karlmaddock is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Wierd glitch problem Perry Electric Off-Road 8 06-29-2007 04:50 AM
wierd engine problem, cannot start uniquexme Onroad Nitro Engine Zone 0 11-19-2006 08:48 PM
Need help! Car being wierd Revox Rookie Zone 11 06-22-2006 01:36 AM
wierd problem need help. boy_racer2k Nitro On-Road 2 04-02-2005 03:15 AM
Need help wierd problem Illusion-Lighti Nitro On-Road 19 08-21-2004 08:33 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 06:30 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net