Findind the lost ark? easy Finding the lost spark? now thats tough ! MYSTERY SOLVED !!!  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Conversions >> Findind the lost ark? easy Finding the lost spark? now thats tough ! MYSTERY SOLVED !!!
Page: [1] 2   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Findind the lost ark? easy Finding the lost spark? now... - 8/27/2008 1:39:53 AM   
foodstick



Posts: 909
Joined: 3/9/2005
From: , IA,
Status: offline 		Ok, I hope I don't get to rambling on what I have tried ( to no avail) but here it goes..

I have a 46cc poulan on the test stand that won't spark/run. It hasn't even made a weak pop.... Now, I have two other of the same motor that I am used to working with ,and they are for the most part rock solid running machines.
Here is the story up to now,

1 The motor ran , but poorly with seemingly bad carb needle settings in the saw.
2 stripped saw, turned carb for better pushrod access, pulls fuel great when choked.
3 Aftermarket exhaust same as other motors.
4 Gas is not old, smells ok.
5 Switched flywheel to 3 magnet type, with 3 magnet coil,small lobe in flywheel was gone, but I carefully aligned flywheel and crank, and smeared a thin coat of jb weld to surfaces, torqued down good.
6 Choke motor, open throttle,hand pull it 5 turns, lower throttle, spin up with 24 volt starter....nothing ....numerous times.
7 I tried another coil..still no spark, pulled coil from a great running motor, no spark
8 Checked coil flywheel gap, set by placing doubled over paper as shim as usual..still nothing
9 Pulled plug from good running motor ...nothing
10 Kill switch wires are off and clear, no apparent shorts possible that way.
11 the motor does seem to be spinning very easy with the starter, might need some oil shot in the plug hole ?
12 Also when spinning up motor with higher throttle setting you can hear that heavy muffled sound that says its getting fuel.
13 I also checked the fuel filter screen in the carb, clean..I haven't opened the diaphragm side since it seems to be pulling.


I think I am honestly still forgetting things I have tried, It has to be something so obvious...even a stuck ring or an internal problem should have sparked at least once I would think?

Thanks for any help..I know this is a doozy of a post !

< Message edited by foodstick -- 9/4/2008 12:20:40 AM >
       Post #: 1

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 1:56:12 AM   
billzair


 

Posts: 135
Joined: 1/28/2003
From: algonquin, IL, USA
Status: offline 		how about a new spark plug? sometimes a crappy running engine has a plug that is fouled just enough to still be runable but will never reach full rpm and run eraticly. or could your coil be grounding out somehow?

_____________________________

If it came from a chainsaw or weedwacker, its GOTTA be good.

(in reply to foodstick)
       Post #: 2

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 1:59:43 AM   
foodstick



Posts: 909
Joined: 3/9/2005
From: , IA,
Status: offline 		I did pull the plug from one of my best motors and installed it..along with the coil from same motor.

(in reply to billzair)
       Post #: 3

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 2:47:43 AM   
billzair


 

Posts: 135
Joined: 1/28/2003
From: algonquin, IL, USA
Status: offline 		what happens when you take the plug out, ground it out on the cylinder and turn the engine over?
Maybe you should put the orginal flywheel and coil back on and give it a shot?
I wouldnt worry about a stuck ring and such until we can figure out why your not getting any spark at the plug.

_____________________________

If it came from a chainsaw or weedwacker, its GOTTA be good.

(in reply to foodstick)
       Post #: 4

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 4:09:16 AM   
buck1856



Posts: 925
Joined: 10/16/2002
From: superior, AZ, USA
Status: offline 		ld first try and get spark like said.Its either the coil,or the plug.But the flywheel and coil must match,a pair.To make the engine run right the flywheel must be at the right position.But you can put the flywheel at any position you want on the crank and it should fire as it passes the coil no matter what its timed at.Did ya look in the rubber boot on coil and make sure the metal plug that fits over the plug is there.Is the cap screwed on tight.I had a twin that wouldnt run right somtimes and the plug was new.Tried it at night and you could see a sprk[very small]coming from between the insulator and hex head once in a while and would short it out.

(in reply to foodstick)
       Post #: 5

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 5:50:52 AM   
foodstick



Posts: 909
Joined: 3/9/2005
From: , IA,
Status: offline 		I will try to see if I can do the sparkplug on top of the motor tomorrow if I can get help as it wouldn't be possible alone..However the last test I did with the motor was using the coil and sparkplug from possibly the best running poulan 46 I own? All of them are three magnet versions, and the motor I am stealing parts off of to test with was running like a champ just a week ago.... I tried using one of those inline sparkplug testers but seems to have a bad bulb in it...

(in reply to buck1856)
       Post #: 6

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 6:09:49 AM   
buck1856



Posts: 925
Joined: 10/16/2002
From: superior, AZ, USA
Status: offline 		When your doing this switching around,maybe the engines are different mounting patterns.See if one of the kill tabs or small lugs are touching somthing thats grounded or the screws are different.It is impossible to take a working ign from one motor and put it on another identical motor and then have it not work unless somthiong isnt bolting up right or somthing grounding out.

(in reply to foodstick)
       Post #: 7

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 4:40:56 PM   
foodstick



Posts: 909
Joined: 3/9/2005
From: , IA,
Status: offline 		Well this morning I tried the sparkplug on the top of the head, and it did spark, I have no idea why it won't pop in the engine. before reinstalling the plug I covered the hole with my thumb and turned the prop by hand,,it has great compression and vacumn. I drained my tank, and poured in gas from my current batch I am running. It is fresh as I seldom mix more than a gallon at a time. spun the motor up ...no ignition, choked it,spun it up..fuel is pulling very well to the carb..Got it wet ..took off choke , turned and turned and turned it with starter, at many different throttle settings, absolutely nothing... I wouldn't be surprised if the carb needs a kit in it..but I don't understand the problem ... I even pulled the plug and shot some fuel directly in the cylinder, same result ..zero ignition....

I don't think it is possible I am flooding it every time as I have tried starting it without any choke, Although now that I think of it I have never got it wet enough to see any gas slop out the exhaust tubes .

< Message edited by foodstick -- 8/27/2008 4:45:48 PM >

(in reply to buck1856)
       Post #: 8

RE: Findind the lost ark? easy Finding the lost spark?... - 8/27/2008 9:51:09 PM   
billzair


 

Posts: 135
Joined: 1/28/2003
From: algonquin, IL, USA
Status: offline 		I bet the timing is some how different between the two fly wheels. you got spark...its problity just happing at the wrong time.


_____________________________

If it came from a chainsaw or weedwacker, its GOTTA be good.

(in reply to foodstick)
       Post #: 9

RE: Findind the lost ark? easy Finding the lost spark... - 8/27/2008 10:03:48 PM   
microsprint9



Posts: 437
Joined: 11/20/2004
From: london, ON, CANADA
Status: offline 		This has nothing to do with your ignition problem, but i see above you said you flipped the carb, there is a small hole that runs from the crankcase to the pump in the carb, make sure it still has a path to the carb, it was my downfall on my first conversion.

(in reply to billzair)
       Post #: 10

RE: Findind the lost ark? easy Finding the lost spark... - 8/28/2008 2:14:02 AM   
captinjohn


 

Posts: 6287
Joined: 1/25/2002
From: Hesperia, MI, USA
Status: offline 		PRIME IT...through the carb....bout 8-10 drops....then see if if pops off! Capt,n

_____________________________

I never met a engine I did not like !

(in reply to microsprint9)
       Post #: 11

RE: Findind the lost ark? easy Finding the lost spark?... - 8/28/2008 2:45:17 AM   
buck1856



Posts: 925
Joined: 10/16/2002
From: superior, AZ, USA
Status: offline 		Maybe the motor your trying is off a blower.Try spinning it CW rotation.Also as stated make sure the pulse hole is lined up.

(in reply to foodstick)
       Post #: 12

RE: Findind the lost ark? easy Finding the lost spark?... - 8/28/2008 3:44:02 AM   
foodstick



Posts: 909
Joined: 3/9/2005
From: , IA,
Status: offline 		Its definately a chainsaw motor as I took it apart myself, and the carb pulse is pulling fuel perfect, you can see it come up the fuel line about 2-3 inchs per revolution when choked. I did prime straight through the sparkplug hole earlier today without results, Tomorrow I will try squirting straight in the carb throat, even though you can hear it sucking fuel when you put the starter on it at about 1/4 throttle...


I must admit I can't seem to wrap my head around what the problem is..If I had any problem with the TWO OTHER IDENTICAL MOTORS, I wouldn't be so surprised...
Oh well, I guess if there was no challenge to rc airplanes... there wouldn't be any reason to be in the hobby !!! ha ha

(in reply to buck1856)
       Post #: 13

RE: Findind the lost ark? easy Finding the lost spark?... - 8/28/2008 4:03:25 AM   
buck1856



Posts: 925
Joined: 10/16/2002
From: superior, AZ, USA
Status: offline 		Maybe one of the motors is a different year or somthing.Ive only come across this once or twice but the keyway when placed pointing at the 12 oclock position the piston was NOT at TDC.[dont remember what engines].Check and see if when you bring the piston up to TDC on all 3 engines the keyway is in the same position on all 3.when at TDC the magnets should be on or about the left side of coil.No matter where the keyway is if its different.

(in reply to foodstick)
       Post #: 14

RE: Findind the lost ark? easy Finding the lost spark?... - 8/28/2008 5:02:08 AM