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Old 08-03-2009, 10:36 AM   #31
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sounds rich... only used rb #6 plugs in mine. o'donell 97 never have run right for me in any rb motor. but others have made them work....
set low needle 3.75-4.25 turns out
set top needle is around 2.75-3.25 turns out.
these are the setting i have been running for years on the c-6's. the 9's are the same from what i have heard from other gyus and parts checking. i have been getting 8-12 gallons out of a motor with these settings also. rb's are a very good and strong motor. take our time start a factory settings and lean out from there slowly. jeremy
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Old 08-03-2009, 01:48 PM   #32
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Quote:
Originally Posted by houston View Post
odonnell 77
x2. if an odo fits its the plug to use. rb plugs are junk
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Old 08-04-2009, 03:38 PM   #33
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I am definitely going to lean the engine more. Unfortunately I will be out of town a couple of days - but I will get back with the outcome of leaning the engine sometime next week.

Thanks for all the feedbacks so far - appreciated.
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Old 08-04-2009, 07:50 PM   #34
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I just got a new left over S3 that leaks like a SOB, but still runs like a top... Smoooooth... Leaks a lot less with an OS carb on it, but regardless... NEVER had a problem with it!

I'd buy another...
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Old 08-09-2009, 05:29 AM   #35
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First of all - thanks for all the feedback.

I ran six tanks (625ml) more or less in a row today without any glow plug problems (using RB's #6). I started out by leaning it slightly on LSN which definitely seemed to do the trick. I think this advice off hand is a good starting point to get the needles right:

Quote:
Originally Posted by jer7469
set low needle 3.75-4.25 turns out
set top needle is around 2.75-3.25 turns out.
One thing I haven't managed to get rid of though is flameouts while refuling. While refuling I let it idle and once filled up I hit the throttle again it bogs down and dies. This happens a couple of times until i burns cleanly and stops coughing. Any advice on this?

Anyway, thanks again. I hope I finally can start spending more time on the track rather than in the pit!

/T
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Old 08-09-2009, 05:52 AM   #36
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lean the bottom out just a little bit more. richen the top to get temp down and/or runs to full rmp range. if the bottom/top are just a little rich the fuel stop flame out occurs.. i like the temps around 240-260 for the c-6/r9. have had very good luck. 8+ gallons on every motor with these temps. hope this helps. jeremy
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Old 08-09-2009, 10:26 AM   #37
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Agreed, lean out the bottom some more.
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Old 08-09-2009, 10:47 AM   #38
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Try a O'Donnell 97T if you have not already, I ran one for the first time yesterday and had great results. Plug looked like brand new after a day of racing.
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Old 08-10-2009, 01:41 AM   #39
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If it doesn’t help with leaning the LS, or/and use a hotter plug, there are still things you can try:

This is from the The Tuning Bible thread http://www.rctech.net/forum/nitro-of...ing-bible.html.

Go to page 5 and read from reply #63

Buttom line is:
You can overfill the tank and thereby drown the engine when you release the tank lid.
Put a pressure chamber in the line between exhaust and fuel tank.

Hope this helps
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Old 09-21-2009, 07:34 AM   #40
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Fellas,

I've pretty much reached a point where I can refuel without flameouts (if I do it fast and rev it intensively .

However I am unable to get a proper idle. When the engine reaches working temperatur (around 110-115C) the idle is fairly high (more than I like). If I stop the car it idles like this for approximately 5-8 seconds. After this it falls down to a perfect idle which is maintained for maybe another 5-8 seconds - then finally it decreases further to a level where it's barely staying alive (resulting in a stall after 5-10 seconds).

Unfortunately increasing idle speed results in an unacceptable high idle for the first 5-8 seconds (especially a problem on power-off over jumps it will be so high it starts to back flip).

Any suggestions fixing this? (I'm thinking improper tuning to some extend. However I don't feel like deviating a whole lot from current setting due to the fact I can refuel without flameout .

Any suggestions appreciated. Thanks!

/Tom
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Old 09-21-2009, 09:15 AM   #41
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Try an O.S P3 plug They seem to give the most consistent iddle Imo and they're more durable than Nova/RB and Odonnel plugs (You also pay the price lol but they're worth it!)
Make sure your iddle gap isn't too small I've seen people twisting needles all day long only to realize they hardly had an opening at iddle lol
Open the Hsn and Lsn about one full turn from where you are now, increase the iddle gap untill it will iddle with these settings put the car on the track and run it for a couple of laps lean the Hsn until your engine is making good power down the straight by this time, your iddle will probably be very high lol adjust the iddle to the point where you have about a 1.5mm gap then tune the Lsn from there
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Old 09-21-2009, 09:19 AM   #42
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Make sure your linkage is holding the carb closed tight. Some spring force needs to be applied.

You should not have the car idle up on its own over jumps. Possibly too lean on bottom or to large an idle gap.

I'd put in a new air filter, new fuel line, new Odonnel 77 plug (hot). Then drive to temp and stop. The RB should idle slightly high for a little while then drop to a regular idle. After 5 solid seconds takeoff. The engine should bog and smoke alot from sitting still. Lean it out a little on bottom till it isn't too boggy but still rich bogs a little. See if that makes a difference.

Your car should be able to get a 4 second pitstop at idle with no revving. Ease into the trigger when you pull away.

Make sure you don't see any air bubbles in your fuel line. Make sure your clutch is fresh. it may not be the engines fault.
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Old 09-21-2009, 09:21 AM   #43
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Yep. Any RB motor I've used has done that one the stock plug. Use an O'Donnell plug and enjoy. If that doesn't work, check your front bearing.


If you have to use an O.S. plug, use the P4. The P3 is too hot.
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Old 09-21-2009, 11:47 AM   #44
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If your RPM is dropping when the engine is left to idle then your low-needle is too rich.

What happens when you let the engine idle for about 15 seconds and then "floor" it? I'm guessing you get a whole lot of smoke and poor acceleration.
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Old 09-21-2009, 11:54 AM   #45
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I had the same problem with my rb s5. When you were flaming out the top was too rich and the idle was too high. Open the throttle all the way and go full brake.... thats how you can tell what your idle is. If the rpms drop bottom is to rich. If the rpms raise to lean on the bottom.

I found rb engines to be a bit different when tuning. great engines though.
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