HPIBajaForumHPIBajaForum  

Go Back   HPIBajaForum > Vendors > Manufacturers/Distributors


Sponsors
RC Discount Search

DGI Racing
LSRC
HPI Racing
FullForceRC
Team Phatdad RC
Killer-RC
Axis R/C
Micro Hobby US
Turtle Racing
Use HBF as the coupon code for 5% off!!!
TFE
Vertigo Performance
ONeill Brothers
Kraken RC

New carb tuning instructions, ESP

Discussion in Manufacturers/Distributors forum, started by EarthSurfer.

Vertigo Performance
Reply
 
Thread Tools
  #1  
Old 02-02-2009, 06:23 AM
EarthSurfer EarthSurfer is offline
Banned
Baja Maniac
 
Join Date: Jul 2006
Location: Grand Rapids, MI.
Posts: 3,028
Trader Feedback: (2)
New carb tuning instructions, ESP

With more people coming into the RC engine, so does the amount of lean seizures. I rewrote my old instructions to what I think is easier to understand. There are other methods people use, but knowing how fast a lean RC engine can seize at higher RPM, I can't think of a safer, in the field, way of tuning the H jet for that day.

Do the new instructions make sense to you? (hard to tell sometimes, when your the guy who wrote it.)





CARB TUNING FOR GAS RC ENGINES

Thank you for buying A ESP engine. This is a guide only. ESP will not be responsible for failures unless it is the fault of ESP workmanship.
Keep in mind that the low speed carb jet screw flows fuel from zero to about 1/3rd throttle opening. The high speed jets starts flowing from about 1/3rd throttle open to full throttle. Both jets flow fuel above 1/3rd throttle.
Set the high speed jet at 2 turns out from bottom to start. Set the low speed jet at about 1& turns out and set the idle up for easier first time starting. Warm the engine on the stand for a few min, rev the engine on the stand a bit while rough setting the low speed jet and idle, for idle to rev throttle response. Close the low speed too far, and the idle goes up and starts vibrating from a lean condition. Open the low to far and the engine will run rich and die. Stay on the rich side, but make sure throttle response from idle is good. Typically, you will end up with a L jet at 1&1/8th to 1&1/2 out. Continue to rev the engine for a few minutes above half throttle, but not holding it in any one position, to run the engine with the high speed jet flowing. Shut it down, and check the plug color. The plug should be a dark color like a dark brown or black. The rich settings we start with could possibly foul a spark plug, so you might want to have a new plug or two on hand for tuning. This dark plug color is good for now, it means we are getting plenty of fuel--at least on the stand.

The H speed jet is critical, and a RC engine can seize in seconds if the fuel/air mixture is lean at high rpm. Because of this, we creep up on high rpm one run at a time, checking the plug for each higher RPM run.

1. With the H speed screw out 2 full turns, run the buggy 30 seconds at a time at about 8,000 to 9,000 rpm (or where your clutch is just engaged). Keep running the buggy at the low RPM until the plug starts building up some dark color. We will need deposit built up on the plug to burn off for “reading the plug”, when we start leaning out the carb H jet later.
2. The plug should stay dark for the rest of this test, until we start adjusting the H screw more lean after we get to full throttle tests. We are now going to raise RPM approx 1000 rpm for 30 seconds for each run, and check the plug after each run to make sure it is still dark. You should have about 10 increments of 1000 rpm from clutch engagement, to full throttle, but the more increments you use, (less RPM rise for each run), the safer you will be. If, while your doing the runs, and getting higher in the rpm, you start seeing the deposit burning off the plug to a brown or lighter color, you have a problem with your fuel system (bad carb, fuel filters, fuel lines) or a possible air leak that you have to fix before you can continue. You may have just saved your engine from a lean seizure.
3. When you get to 30 sec full throttle runs with a dark plug, now it is time to start leaning out the H jet. After a full throttle run, check the plug, and it should still be dark with the H screw 2 full turns out. Turn in the screw 1/16th at a time, and continue doing full throttle runs, plug checks, and H screw carb adjustments, until the plug is a brown paper bag color. Do one or two full throttle runs to make sure the plug does not get any lighter. Then fine tune the low speed jet for the best hole shot, and your done. It is a good idea to write down the amount of turns you are at when done, for a reference.

Note, many carb bolts are too long. If your long carb bolts (that hold on the filter, and go through the carb, into the intake manifold), reach all the way through your intake manifold, you will have to shorten the bolts, or risk a damaged cylinder and air leak, possibly seizing the engine.

To help insure you don’t seize your engine due to a carb failure or clogged fuel filters, etc (something other than your set screws), it is a good idea to do a few increments and plug checks every time you take out the machine. Jet richer on cold days, and always re jet for any modification you may make. There is no such thing as “stock settings”, jet it yourself from scratch, or risk seizing the engine.
Reply With Quote
  #2  
Old 02-02-2009, 07:49 AM
Shortfuse206 Shortfuse206 is offline
Senior Member
Baja Maniac
 
Join Date: Nov 2007
Location: Shelby Twp. Michigan
Posts: 3,463
Trader Feedback: (26)
good work Doug the new instructions are nice they make good sense
Reply With Quote
  #3  
Old 02-02-2009, 08:42 AM
Baja Storm's Avatar
Baja Storm Baja Storm is offline
Contributor - All
Baja Maniac
 
Join Date: Oct 2007
Location: Notts, UK
Posts: 5,285
Trader Feedback: (27)
Great stuff Doug!
Please check your pm.
__________________

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #4  
Old 02-02-2009, 08:45 AM
Urbandrag Urbandrag is offline
Senior Member
Baja Maniac
 
Join Date: Jan 2009
Location: Argentina
Posts: 496
Trader Feedback: (22)
Sticky?
Reply With Quote
  #5  
Old 02-02-2009, 08:55 AM
02cummins 02cummins is offline
Senior Member
Baja Maniac
 
Join Date: Aug 2008
Location: livermore ca
Posts: 2,104
Trader Feedback: (15)
seems to me pretty detailed on explaining everything, great job Doug
Reply With Quote
  #6  
Old 02-02-2009, 10:39 AM
Mohammed T Mohammed T is offline
Senior Member
Baja Maniac
 
Join Date: Apr 2007
Location: Saudi Arabia
Posts: 3,170
Trader Feedback: (2)
Thanks for putting this up Doug
Reply With Quote
  #7  
Old 02-02-2009, 12:06 PM
hughes5000c hughes5000c is offline
Member
Baja Maniac
 
Join Date: Oct 2008
Location: UPSTATE NY
Posts: 123
Trader Feedback: (2)
Thanx..Doug.........
Reply With Quote
  #8  
Old 02-02-2009, 12:16 PM
steliosh steliosh is offline
Senior Member
Baja Maniac
 
Join Date: Aug 2008
Location: Athens, Greece
Posts: 287
Trader Feedback: (0)
thanks, Doug!
Reply With Quote
  #9  
Old 02-02-2009, 12:30 PM
nothinbetr2do nothinbetr2do is offline
Baja Addict
Baja Maniac
 
Join Date: Jan 2008
Location: elkton, maryland
Posts: 3,177
Trader Feedback: (10)
awesome. thanks for posting this doug, it should really come in handy
Reply With Quote
  #10  
Old 02-02-2009, 02:06 PM
Jeff1974 Jeff1974 is offline
Banned
Baja Maniac
 
Join Date: Apr 2007
Location: The Netherlands
Posts: 2,089
Trader Feedback: (2)
Thumbs up

great update Doug!
Reply With Quote
  #11  
Old 02-02-2009, 02:14 PM
tiny tiny is offline
Senior Member
Baja Maniac
 
Join Date: Feb 2008
Location: malvern,arkansas
Posts: 7,502
Trader Feedback: (25)
Great job Doug.
Reply With Quote
  #12  
Old 02-04-2009, 03:24 AM
feral five B feral five B is offline
Senior Member
Baja Maniac
 
Join Date: Oct 2008
Location: Perth Western Australia
Posts: 2,687
Trader Feedback: (1)
Thumbs up

thanks doug should put alot of ppl straight on how to set their carb/motor when new,very easy to read and understand
Reply With Quote
  #13  
Old 02-04-2009, 10:47 AM
EarthSurfer EarthSurfer is offline
Banned
Baja Maniac
 
Join Date: Jul 2006
Location: Grand Rapids, MI.
Posts: 3,028
Trader Feedback: (2)
Good, glad to see the response is that it is understandable. Thanks for your input also. Hopefully, this will help keep lean seizures to a minimum.

For some engines, like reed case engines, the starting settings may be a bit too rich. For reed case engines it might be better to start off with the L at 1&1/4, and the H at 1&3/4 out. Just make sure the plug is and stays dark while you creep up to full throttle.

Last edited by EarthSurfer; 02-04-2009 at 10:53 AM.
Reply With Quote
  #14  
Old 02-04-2009, 10:53 AM
Anthony DePhillips's Avatar
Anthony DePhillips Anthony DePhillips is offline
Horizon Hobby Surface Product Manager
Baja Maniac
 
Join Date: Oct 2007
Location: inland empire
Posts: 826
Trader Feedback: (4)
thank you very much
Reply With Quote
  #15  
Old 02-04-2009, 10:56 AM
Jeff1974 Jeff1974 is offline
Banned
Baja Maniac
 
Join Date: Apr 2007
Location: The Netherlands
Posts: 2,089
Trader Feedback: (2)
Quote:
Originally Posted by EarthSurfer View Post
Good, glad to see the response is that it is understandable.
Huh?! What do you mean? Just kidding
Reply With Quote
  #16  
Old 02-04-2009, 03:39 PM
Bajacommander Bajacommander is offline
Baja Expert
Baja Maniac
 
Join Date: Mar 2008
Location: sterling heights MI
Posts: 740
Trader Feedback: (1)
doug, all the years ive been in the hobby(and i can say that) seizures on break in come from only one thing, impatience. too many people want to grip it and rip it, and thats just not how it works. i think its unfortunate you have to protect yourself from other peoples mistakes.

you need to start printing some T-shirts
Reply With Quote
  #17  
Old 02-04-2009, 04:49 PM
Denz Denz is offline
Member
Baja Maniac
 
Join Date: Jan 2009
Location: Camberwell, London, UK
Posts: 220
Trader Feedback: (1)
great job doug, ill be retunning my carb with this setting. thanks
Reply With Quote
  #18  
Old 02-06-2009, 09:21 PM
Baja Racer Baja Racer is offline
Member
Baja Maniac
 
Join Date: Sep 2008
Location: Peebles, Ohio
Posts: 246
Trader Feedback: (0)
Thanks a lot. I'll be using your methods on all of my future engines.
Reply With Quote
  #19  
Old 02-08-2009, 04:09 AM
EarthSurfer EarthSurfer is offline
Banned
Baja Maniac
 
Join Date: Jul 2006
Location: Grand Rapids, MI.
Posts: 3,028
Trader Feedback: (2)
Quote:
Originally Posted by Bajacommander View Post
doug, all the years ive been in the hobby(and i can say that) seizures on break in come from only one thing, impatience. too many people want to grip it and rip it, and thats just not how it works. i think its unfortunate you have to protect yourself from other peoples mistakes.

you need to start printing some T-shirts
I think, if your going to use the RC engine, your gonna seize at least once sooner or later. There are several other resaons for a lean seize, besides carb tuning, and some can catch you buy suprise. I grew up using and working on two stroke engines, and I have been burned with the RC engine several times. But yea, many of them are from
"lets see what this thing can do!" (usually the case with a brand new engine) before you know your safe.

I do have some T- shirts. I will ask DDM if he would like to stock some.
Reply With Quote
  #20  
Old 02-08-2009, 07:48 AM
Mohammed T Mohammed T is offline
Senior Member
Baja Maniac
 
Join Date: Apr 2007
Location: Saudi Arabia
Posts: 3,170
Trader Feedback: (2)
Doug, would you consider this a perfect color for a plug? Lighter, Darker?



Thanks
Reply With Quote
Reply

Share This Post


Thread Tools

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

Forum Jump

Forum Jump

All times are GMT -8. The time now is 03:26 AM.


Powered by vBulletin - Copyright 2000 - 2014, Jelsoft Enterprises Ltd.
Neither this website nor the forum provided is affiliated with, or endorsed, by Hobby Products International, Inc. (HPI). Further, this website is not affiliated with, or endorsed by, the owners of any the trademarks, service marks or trade names referred to by this website or within the forum unless specifically and expressly indicated. Any trademarks, service marks or trade names referred to on this website or in the forum remain the full property of their respective owners. The opinions expressed in the forum reflects solely the opinion(s) of the participants, visitors and members and may not reflect the opinion(s) of the website owner.