Tuning help, lean after high speed pass
01-12-2004, 05:29 PM
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Tuning help, lean after high speed pass
I have a XTM 24.7 motor in my savage and I have a question about tuning it. When I let off the gas after a high speed pass the motor flutters and sounds like its running lean as it comes down to a idle. Do I need to adjust the high speed needle or low speed needle to resolve this? I am guessing it’s the high speed needle because I think my low speed needle is running very rich.
01-12-2004, 08:56 PM
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RE: Tuning help, lean after high speed pass
Chances are you need to adjust both. If you are running really rich on the bottom end and lean on the high end the transition will be sucky at best. Adjust the high speed first, if richening it up doesnt help and the problem persists the lean out the bottom end. Of course you could be running rich on the high end and lean on the low end and have a similar problem. Troubleshooting is the only way to solve it. When you trouble shoot you need to make sure you only fiddle with one needle at a time.
01-14-2004, 01:58 AM
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RE: Tuning help, lean after high speed pass
Here, a picture is worth 1000 words..............
[link=http://centurytel.net/lizy/tuning.jpg]Tune me, Big Boy![/link]
[link=http://centurytel.net/lizy/tuning.jpg]Tune me, Big Boy![/link]
01-14-2004, 08:13 AM
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RE: Tuning help, lean after high speed pass
Thanks for all the help. Right now the transition is really bad between HSN and LSN. I broke in per XTM manual. It was 28 degrees out so factory settings were way to rich for it to run right. On my last run I leaned my HSN way too much. I blew a glow plug. My bottom end was still way to rich, so the transition sucked bad. Lots and lots of smoke on the bottom end but none up top. I think I have already leaned my LSN a full turn and its still really rich. What is the factory LSN setting for the xtm 24.7 (non-pro)?
Also I am running a MC-59 glow plug with 20% fuel. I have always run #8 with my 21bb. Should I go back to #8 plugs?
Thanks for the flow chart. That rocks!!
Also I am running a MC-59 glow plug with 20% fuel. I have always run #8 with my 21bb. Should I go back to #8 plugs?
Thanks for the flow chart. That rocks!!
01-14-2004, 09:40 AM
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RE: Tuning help, lean after high speed pass
Remember, with colder temps you have to run a richer setting than in warmer weather. I prefer the #8, especially in cooler weather.
01-14-2004, 10:19 AM
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RE: Tuning help, lean after high speed pass
The number 8 is a hotter glow plug. I run 15 percent nitro, 18 percent oil, and use an OS A8 plug. Richen your high speed needle a turn and a half. Remember, work from rich to lean, not lean to rich. 
01-14-2004, 10:42 AM
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RE: Tuning help, lean after high speed pass
ORIGINAL: teamsquirreltail
The number 8 is a hotter glow plug. I run 15 percent nitro, 18 percent oil, and use an OS A8 plug. Richen your high speed needle a turn and a half. Remember, work from rich to lean, not lean to rich.
The number 8 is a hotter glow plug. I run 15 percent nitro, 18 percent oil, and use an OS A8 plug. Richen your high speed needle a turn and a half. Remember, work from rich to lean, not lean to rich.
I thought #8 is a medium-cold plug and MC-59 (the plug I am running currently) is a hot plug? What temp range of plug should I run in Hot/Cold weather?
