R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 08-13-2010, 10:49 AM   #1
Tech Regular
 
Join Date: Oct 2009
Location: Sweden
Posts: 314
Default What would make a glow plug die @ IDLE?

Here's the deal.

Engine runs fine although perhaps just a tad to lean/hot rather then rich.
I can run WOT over and over with perfect smoke.
It has great launch and and sounds OK.
As long as I keep it running (for several tanks) the engine will run fine.
If I refuel I can keep the throttle on a little bit and everything is fine.
But if I let it idle for only a few seconds it will rev down and die.
After that the glow plug is done and will not even glow with it out of the engine and into the glow igniter.
This happens OVER and OVER again with brand new plugs.
I run recommended plugs on 20% and the engine is under 1 gallon so far.
I have taken it apart and checked bearings and cleaned carb and everything else.

What could this be?
__________________
Life's like a lemon and I want my money back!
Klimpen717 is offline   Reply With Quote
Old 08-13-2010, 10:53 AM   #2
Tech Lord
 
wingracer's Avatar
 
Join Date: Nov 2007
Posts: 12,781
Trader Rating: 23 (100%+)
Default

Quote:
Originally Posted by Klimpen717 View Post
Here's the deal.

Engine runs fine although perhaps just a tad to lean/hot rather then rich.
I can run WOT over and over with perfect smoke.
It has great launch and and sounds OK.
As long as I keep it running (for several tanks) the engine will run fine.
If I refuel I can keep the throttle on a little bit and everything is fine.
But if I let it idle for only a few seconds it will rev down and die.
After that the glow plug is done and will not even glow with it out of the engine and into the glow igniter.
This happens OVER and OVER again with brand new plugs.
I run recommended plugs on 20% and the engine is under 1 gallon so far.
I have taken it apart and checked bearings and cleaned carb and everything else.

What could this be?
The element is breaking while you are running, probably because it's lean and hot. It will keep running if though broke but of course, can't be re-fired.

What engine and what plug? A lot of plugs have gone to a cheaper element to keep costs down but they just don't last anymore.

Also, how old is the engine? Have you ever replaced the rod?
__________________
Sean. Certified speed crazed mowron.
Team Shepherd USA
www.ashfordhobby.com
wingracer is offline   Reply With Quote
Old 08-13-2010, 11:00 AM   #3
Tech Prophet
 
tc5 man's Avatar
 
Join Date: Oct 2007
Location: levittown pa
Posts: 16,872
Default

well i did have a similar problem, with my glow plug it whouldnt get a constant idle but it , whould start up fine but during the race run like crap and flame out. and i wasnt running lean ethier

but i put a new plug in and its fine now and idles great.

i dint know companys are using cheaper elements now.
tc5 man is online now   Reply With Quote
Old 08-13-2010, 12:38 PM   #4
Tech Elite
 
NitroXray80809's Avatar
 
Join Date: Mar 2010
Location: Bakersfield, California
Posts: 3,249
Trader Rating: 24 (100%+)
Default

Is the plug discolored at the tip when u take it out of the engine? If it is in one day of running ur to lean which will also gurantee ur engine not lasting much longer running hot, If ur only a gallon in the engine you shouldnt be running it a tad hot it should still be rich because most engines dont even break in till after a gallon. Also if you didnt do a proper break in the engine will always have issues, ive seen a novarossi last 3 days because the guy just threw it in the truggy and opened it up like it was broke in.
__________________
Xray XB4 | Ko-Propo | Savox | Hobbywing | SpeedPassion | JC |

Kyosho RB6 | Ko-Propo | Futaba | Turnigy | Orion | JC |

AE T4.2 | Ko-Propo | Savox | Turnigy | ProTek | JC |
NitroXray80809 is offline   Reply With Quote
Old 08-13-2010, 01:32 PM   #5
Tech Master
 
Join Date: Dec 2009
Location: Quinby south Carolina
Posts: 1,157
Trader Rating: 20 (100%+)
Default

i can almost garentee ur rod bushings r shot, i have the EXACT symtoms 2 times n both times my rod bushing were the issue. the first time the upper bushing in the piston totally went, 2nd time the lower bushing had gone outta rounds. i keptpopping plugs n i was pissed!
Matt Piva is offline   Reply With Quote
Old 08-13-2010, 01:34 PM   #6
Tech Regular
 
Join Date: Oct 2009
Location: Sweden
Posts: 314
Default

Quote:
Originally Posted by NitroXray80809 View Post
Is the plug discolored at the tip when u take it out of the engine? If it is in one day of running ur to lean which will also gurantee ur engine not lasting much longer running hot, If ur only a gallon in the engine you shouldnt be running it a tad hot it should still be rich because most engines dont even break in till after a gallon. Also if you didnt do a proper break in the engine will always have issues, ive seen a novarossi last 3 days because the guy just threw it in the truggy and opened it up like it was broke in.
Yes it is a bit brownish rather then ash grey

It is not a day of running, it's ANY AMOUNT of driving until you let it idle for more then 15-20 seconds or so. THEN the plug dies. Pop in a new one and repeat. You can drive one hour straight with no issues but as soon as you let it idle for a longer period of time that plug also dies, repeat again.

This one is broken in and "dropped the balls" already. I said lean rather then rich just to let you know i was NOT running too rich and therefor burning plugs.

I did OF COURSE do a proper break in (heat cycle).





Quote:
Originally Posted by Matt Piva View Post
i can almost garentee ur rod bushings r shot, i have the EXACT symtoms 2 times n both times my rod bushing were the issue. the first time the upper bushing in the piston totally went, 2nd time the lower bushing had gone outta rounds. i keptpopping plugs n i was pissed!
Is that even possible after less then a gallon?
I will take it apart again and look at the bushings.
What is it with a bad bushing that eats plugs? Whats the thinking behind it?
__________________
Life's like a lemon and I want my money back!
Klimpen717 is offline   Reply With Quote
Old 08-13-2010, 01:42 PM   #7
Tech Elite
 
NitroXray80809's Avatar
 
Join Date: Mar 2010
Location: Bakersfield, California
Posts: 3,249
Trader Rating: 24 (100%+)
Default

sounds like a tune issue more than anything if the plugs are turning discolored.
__________________
Xray XB4 | Ko-Propo | Savox | Hobbywing | SpeedPassion | JC |

Kyosho RB6 | Ko-Propo | Futaba | Turnigy | Orion | JC |

AE T4.2 | Ko-Propo | Savox | Turnigy | ProTek | JC |
NitroXray80809 is offline   Reply With Quote
Old 08-13-2010, 02:23 PM   #8
Tech Prophet
 
tc5 man's Avatar
 
Join Date: Oct 2007
Location: levittown pa
Posts: 16,872
Default

Yes it is a bit brownish rather then ash grey

It is not a day of running, it's ANY AMOUNT of driving until you let it idle for more then 15-20 seconds or so. THEN the plug dies. Pop in a new one and repeat. You can drive one hour straight with no issues but as soon as you let it idle for a longer period of time that plug also dies, repeat again.



This one is broken in and "dropped the balls" already. I said lean rather then rich just to let you know i was NOT running too rich and therefor burning plugs.

I did OF COURSE do a proper break in (heat cycle).





i just replace my plug from, the one gallon i ran raced it but it was rich on the low end and running about 235 degress. and it actally gave up before my second gallon really because, it would just would keep on loading up and not idleing right . even if i tried to lean the low end to stop it from doing that and, i even messed with the high end needle a bit.

but with the new plug, the low end runs, better and a constant idle with no drop off and a new fresh prefilter filter and inner filter, and there was a light blue smoke when i hit the gas.


i got my broken in my edmods, and like a dummy dint ask how many tanks he ran though it . but its still tight enough were i cant turn the piston over by hand.

and the old plug, was brown on the suface and the coils i dint check but i am going to.




Is that even possible after less then a gallon?
I will take it apart again and look at the bushings.
What is it with a bad bushing that eats plugs? Whats the thinking behind it?[/QUOTE]
tc5 man is online now   Reply With Quote
Old 08-13-2010, 02:32 PM   #9
Tech Fanatic
 
wolf16731's Avatar
 
Join Date: Apr 2010
Location: Ellsworth AFB, SD
Posts: 810
Trader Rating: 9 (100%+)
Send a message via Yahoo to wolf16731
Default

How are the clutch bearings? If there is a little too much drag that might be causing the issue. But I am not so sure that it would pop the plug every time because of clutch bearings...
__________________
HPI Blitz ESE- Castle SCT Sidewinder brushless system
TLR 22SCT- Tekin RS; 8.5T Gen2
HPI MT2SC- HPI .18SS
HPI Savage- Dynamite Mach 2 Big Red .28
wolf16731 is offline   Reply With Quote
Old 08-13-2010, 02:35 PM   #10
Tech Prophet
 
tc5 man's Avatar
 
Join Date: Oct 2007
Location: levittown pa
Posts: 16,872
Default

Quote:
Originally Posted by wolf16731 View Post
How are the clutch bearings? If there is a little too much drag that might be causing the issue. But I am not so sure that it would pop the plug every time because of clutch bearings...


who me my clutch bearings are fine.
tc5 man is online now   Reply With Quote
Old 08-13-2010, 02:46 PM   #11
cdc
Tech Regular
 
Join Date: May 2010
Posts: 386
Trader Rating: 8 (100%+)
Default

clutch bearing would not cause the glow plug to go bad.
__________________
Kyosho MP9 TKI4 - OS SPEED - KO RSx Servos - Futaba 4PX
cdc is offline   Reply With Quote
Old 08-13-2010, 02:49 PM   #12
Tech Prophet
 
tc5 man's Avatar
 
Join Date: Oct 2007
Location: levittown pa
Posts: 16,872
Default

Quote:
Originally Posted by cdc View Post
clutch bearing would not cause the glow plug to go bad.

yea i dont think they would, but i do know that if the crankshaft is worn and the bushing also it will eat up plugs.

my old plug still lights up, but the coils must of been bad or something.
tc5 man is online now   Reply With Quote
Old 08-13-2010, 02:54 PM   #13
cdc
Tech Regular
 
Join Date: May 2010
Posts: 386
Trader Rating: 8 (100%+)
Default

A glow plug can be bad and still light up
__________________
Kyosho MP9 TKI4 - OS SPEED - KO RSx Servos - Futaba 4PX
cdc is offline   Reply With Quote
Old 08-13-2010, 02:56 PM   #14
Tech Prophet
 
tc5 man's Avatar
 
Join Date: Oct 2007
Location: levittown pa
Posts: 16,872
Default

Quote:
Originally Posted by cdc View Post
A glow plug can be bad and still light up

yea i know that now lol im using #100 odonnel plugs.
its weird though when, i ran the nova plugs i never had any flame outs.

and i ran the nova plug for about 1 gallon and a full quart of fuel.
tc5 man is online now   Reply With Quote
Old 08-13-2010, 03:11 PM   #15
Tech Addict
 
Join Date: Apr 2008
Posts: 544
Default

I've only seen the rod bushing thing happen once, but it would blow the plug immediately, and obliterate it at that.

It sounds kinda like the engine is a little hot. If the engine runs too lean, a lot of times it can still stay running, but the plug filiment will have enough of a crack or break to keep it from refiring.
__________________
Shaun Davis
VP ProUSA
Mugen Seiki/Alpha Engines
Team Trinity
Miniracer23 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Grande Prairie Model Racers Association WheelNut Canadian R/C Scene 19805 06-10-2017 01:40 PM
N.O.R.A. SATURDAY NIGHT SUMMER OFF-ROAD SERIES Dude C. Northwest Racers 654 10-01-2008 07:47 PM
Beginner - trouble tuning idle so car will sit still jcaudill Nitro On-Road 21 06-27-2005 04:46 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 08:15 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net