Go Back  R/C Tech Forums > General Forums > Nitro Off-Road > Offroad Nitro Engine Forum
Tuning the low end and idle of an engine >

Tuning the low end and idle of an engine

Tuning the low end and idle of an engine

Old 02-26-2011, 09:15 PM
  #1  
Tech Addict
Thread Starter
iTrader: (8)
 
Join Date: Mar 2010
Posts: 614
Trader Rating: 8 (100%+)
Default Tuning the low end and idle of an engine

Whats your method?

I hear alot of motors that when you let off after the straight you get alittle "back fire" sound. Try to tune that out of the motor then you get flame outs due to the bottom being too fat or idle gap too small. Top is not lean. So what is producing this sound? Is it bad? Motors seem to run fine otherwise. No high hanging idle. Also, i noticed on my ninja it doesn't wanna idle until its warmed up. Try to lean the bottom or open the gap once it gets up to temp it sounds worse. Not sure about that one.
bacchus is offline  
Old 02-27-2011, 12:18 AM
  #2  
Tech Addict
 
VWVR6_T's Avatar
 
Join Date: Feb 2010
Location: Western,PA
Posts: 560
Default

I see that you have a B5, If you used Ron's method on the B5 and B6 first page in the thread It will help you. You can used that method in any engine in the market not just WERKS. Now, Raise the compression too high will back fire, no properly tune will back fire. Did you took any shims out?
VWVR6_T is offline  
Old 02-27-2011, 12:31 AM
  #3  
Tech Master
iTrader: (2)
 
Flanno's Avatar
 
Join Date: Jun 2009
Location: Sydney
Posts: 1,566
Trader Rating: 2 (100%+)
Default

Sounds ok to me...my 5 port GO does the same thing and when try to tune it out it runs like a dog, so I understand that that certain engine of mine just likes that tune........... is 80 ltrs old and have had no dramma's running like that.

The only needle I touch is the high end needle, once my bottom end is set as below.

If tune changes drastically then I check all other factors before touching needles....fuel line, plug, (if plug richen 1 hour) pipe seals, tank lid, etc etc etc

My method from scratch is I lean bottom end in small incriments untill idle rises slightly, then reduce idle and repeat untill reducing idle doesn't actually reduce idle at all, then richen bottom end by 2 hours if imagining the needle slot is hands on a clock, then set idle on a hot raced temp engine not on a warm or cold engine.

Hope that helps.
Flanno is offline  
Old 02-27-2011, 08:23 AM
  #4  
Tech Addict
Thread Starter
iTrader: (8)
 
Join Date: Mar 2010
Posts: 614
Trader Rating: 8 (100%+)
Default

Originally Posted by VWVR6_T View Post
I see that you have a B5, If you used Ron's method on the B5 and B6 first page in the thread It will help you. You can used that method in any engine in the market not just WERKS. Now, Raise the compression too high will back fire, no properly tune will back fire. Did you took any shims out?
Actually i'm running a mugen ninja now with a 2035. The B5 did the same thing with stock shimming. I here a lot of peoples engines at the track doing that. Then i hear some not doing it. But like i said if you try and tune that out it just seems like you can't.
bacchus is offline  
Old 02-27-2011, 08:37 AM
  #5  
Tech Adept
iTrader: (6)
 
hyperc10's Avatar
 
Join Date: Sep 2009
Location: Midwest
Posts: 244
Trader Rating: 6 (100%+)
Default

Try running a med. or colder plug.
hyperc10 is offline  
Old 02-27-2011, 09:30 AM
  #6  
Tech Champion
iTrader: (11)
 
Maximo's Avatar
 
Join Date: Jan 2005
Posts: 7,901
Trader Rating: 11 (100%+)
Default

Sometimes an engine is just going to do that under certain conditions no matter what....If you can't dial it out with the needles sometimes you can dial it out with a different plug or pipe..... Sometimes its a sign of fuel tank issues as well...if its more pronounced during a sharp turn at the end of the straight, or hitting the brakes after a straight its sometime caused from inconsistent fuel pickup in the tank....Personally it annoys me when an engine does that, so I will usually tinker with them till I can make it go away..... In the Mugens its usually the fuel tank....
Maximo is offline  
Old 02-27-2011, 09:32 AM
  #7  
Tech Champion
iTrader: (11)
 
Maximo's Avatar
 
Join Date: Jan 2005
Posts: 7,901
Trader Rating: 11 (100%+)
Default

Originally Posted by bacchus View Post
Actually i'm running a mugen ninja now with a 2035. The B5 did the same thing with stock shimming. I here a lot of peoples engines at the track doing that. Then i hear some not doing it. But like i said if you try and tune that out it just seems like you can't.
Some Ninja's can be really tricky to dial that out...of all the OS engines the Ninja's seem the most prone to running on...some will do it, some will not..not sure why tho !
Maximo is offline  
Old 02-27-2011, 09:39 AM
  #8  
Tech Addict
Thread Starter
iTrader: (8)
 
Join Date: Mar 2010
Posts: 614
Trader Rating: 8 (100%+)
Default

Originally Posted by Maximo View Post
Some Ninja's can be really tricky to dial that out...of all the OS engines the Ninja's seem the most prone to running on...some will do it, some will not..not sure why tho !
It doesn't run me on I was just wondering about it. Fuel system is all new. Whats more concerning to me is that it won't idle until its warmed up. You start it on the box do small revs and if you try and let it fully idle it dies. But once its warmed up runs like a champ. Try and dial that out by opening idle gap OR leaning bottom end it will idle high on the track at race temp. I guess that just the nature of race engines? I haven't really messed with it too much since it runs great otherwise...maybe next race i'll really work on getting that straight.
bacchus is offline  
Old 02-27-2011, 09:40 AM
  #9  
Tech Addict
Thread Starter
iTrader: (8)
 
Join Date: Mar 2010
Posts: 614
Trader Rating: 8 (100%+)
Default

Originally Posted by hyperc10 View Post
Try running a med. or colder plug.
Kinda what i was thinking as well. I'm running P3's now and will try a P4 next.
bacchus is offline  
Old 02-27-2011, 09:47 AM
  #10  
Tech Champion
iTrader: (11)
 
Maximo's Avatar
 
Join Date: Jan 2005
Posts: 7,901
Trader Rating: 11 (100%+)
Default

Originally Posted by bacchus View Post
It doesn't run me on I was just wondering about it. Fuel system is all new. Whats more concerning to me is that it won't idle until its warmed up. You start it on the box do small revs and if you try and let it fully idle it dies. But once its warmed up runs like a champ. Try and dial that out by opening idle gap OR leaning bottom end it will idle high on the track at race temp. I guess that just the nature of race engines? I haven't really messed with it too much since it runs great otherwise...maybe next race i'll really work on getting that straight.
Some engines wont idle correctly till they are warmed up fully....tho OS are usually pretty forgiving on a cold idle..... But for the most part you can't expect a perfect idle when they are cold...
Maximo is offline  
Old 02-27-2011, 10:13 AM
  #11  
Tech Addict
Thread Starter
iTrader: (8)
 
Join Date: Mar 2010
Posts: 614
Trader Rating: 8 (100%+)
Default

Originally Posted by Maximo View Post
Some engines wont idle correctly till they are warmed up fully....tho OS are usually pretty forgiving on a cold idle..... But for the most part you can't expect a perfect idle when they are cold...
Good to know. Thanks.
bacchus is offline  
Old 02-27-2011, 10:24 AM
  #12  
Tech Addict
iTrader: (12)
 
hdcruzer's Avatar
 
Join Date: Sep 2009
Location: Pittsburg Ca.
Posts: 737
Trader Rating: 12 (100%+)
Default

Originally Posted by bacchus View Post
It doesn't run me on I was just wondering about it. Fuel system is all new. Whats more concerning to me is that it won't idle until its warmed up. You start it on the box do small revs and if you try and let it fully idle it dies. But once its warmed up runs like a champ. Try and dial that out by opening idle gap OR leaning bottom end it will idle high on the track at race temp. I guess that just the nature of race engines? I haven't really messed with it too much since it runs great otherwise...maybe next race i'll really work on getting that straight.
If its idleing high at race temp,one of two things. Your idle gap is to wide or your LSN is to lean. Once you get the idle set right warm to hot you should never have to mess with it again. Just the HSN for weather conditions. Unless you warm the motor when its cold it will not idle until it reaches operating temps.
hdcruzer is offline  
Old 02-27-2011, 11:09 AM
  #13  
Tech Addict
Thread Starter
iTrader: (8)
 
Join Date: Mar 2010
Posts: 614
Trader Rating: 8 (100%+)
Default

Originally Posted by hdcruzer View Post
If its idleing high at race temp,one of two things. Your idle gap is to wide or your LSN is to lean. Once you get the idle set right warm to hot you should never have to mess with it again. Just the HSN for weather conditions. Unless you warm the motor when its cold it will not idle until it reaches operating temps.
So you experience the same thing? No idle when cold?
bacchus is offline  
Old 02-27-2011, 11:15 AM
  #14  
Tech Addict
iTrader: (12)
 
hdcruzer's Avatar
 
Join Date: Sep 2009
Location: Pittsburg Ca.
Posts: 737
Trader Rating: 12 (100%+)
Default

Originally Posted by bacchus View Post
So you experience the same thing? No idle when cold?
No it will idle when its cold I just have blip the throttle to keep it running until it warms up. In my experience no motor will idle straight up cold it will run but wont idle until its up to temp......
hdcruzer is offline  
Old 02-27-2011, 11:50 AM
  #15  
Tech Addict
Thread Starter
iTrader: (8)
 
Join Date: Mar 2010
Posts: 614
Trader Rating: 8 (100%+)
Default

Talked to a buddy of mine at the track and he said his ninjas idle from cold to hot. I'm starting to think i'm fat on the bottom lean on top...like i said i'm gonna tune on it and try and figure it out.
bacchus is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.