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Alien
Apprentice
Canada
149 Posts |
 Posted - Dec 15 2002 : 10:28:30 AM
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We just opened the cylinder to clean it, it had about 5mm of burned up oil or whatever it was...After that we got it to start a bit. We checked the ignition it's working pretty good, we tryed a new spark plug: same thing... So another problem could be the flywheel or the intake could need cleaning or something....
I'll take a look in some books...
I Love Lawnmowers...
(I edited the title....Aaron)
Edited by - Aaron Cake on Dec 15 2002 11:55:24 AM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Dec 15 2002 : 11:54:25 AM
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You need to assume a logical approach to things.
First of all, when you reinstalled the cylinder head, did you use a new gasket and torque to the proper value and in the right sequence? If not, then you will need to remove the head, replace the gasket and then reinstall properly. I hope you didn't warp the head, and the bolts are only supposed to be at 15-17 LBS or something like that.
Second, test the spark. Do you get good ignition? If not, replace the points (if equipped).
Third, fuel. Carbs do not go spontaniously out of adjustment, so unless you have touched it the fuel mixture should be good. Even if it is out of adjustment, the engine will still start and run, just not well.
Your problem seems to be an ignition problem. More than likely the condensor and/or points are bad.
Flywheel problems are almost nonexistant, and dirt will not be the cause unless the carb is clogged internally.
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n/a
DELETED (Inactive)
1 Posts |
Posted - Jan 04 2003 : 3:21:42 PM
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quote:
You need to assume a logical approach to things.
First of all, when you reinstalled the cylinder head, did you use a new gasket and torque to the proper value and in the right sequence? If not, then you will need to remove the head, replace the gasket and then reinstall properly. I hope you didn't warp the head, and the bolts are only supposed to be at 15-17 LBS or something like that.
Second, test the spark. Do you get good ignition? If not, replace the points (if equipped).
Third, fuel. Carbs do not go spontaniously out of adjustment, so unless you have touched it the fuel mixture should be good. Even if it is out of adjustment, the engine will still start and run, just not well.
Your problem seems to be an ignition problem. More than likely the condensor and/or points are bad.
Flywheel problems are almost nonexistant, and dirt will not be the cause unless the carb is clogged internally.
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Alien
Apprentice
Canada
149 Posts |
Posted - Feb 16 2003 : 7:56:19 PM
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Damn, i really don't see a point in copying that... Do you?
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Andrew
13/m/Canada
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n/a
DELETED (Inactive)
10 Posts |
Posted - Mar 01 2003 : 07:13:13 AM
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HAHAHA.. sorry, but I really have to reply to this... in year 11 Energy Technology at school, we had to dismantle, and reassemble.. well, my group was the first to finish (I have very little to do with the reassembly) anyway, we pulled the cord, and it started.. and ran.. :) The teacher promised us a good mark.. A few days later, we pulled teh engine from its box again, set it up, and started it... After running for a few seconds, it seemed to rapidly speed up and make a TERRIBLE noise, before my friend could do anything there was a BaNg and the engine seized... OHH NOO!!! now we're in trouble... we pulled the side off it again, and peered inside... The big end had snapped through, and one of the bolts that held it on had come TOTALLY undone, not a single stripped thread..  We managed to convince the teacher that the engine blew cos it was old, and worn... I looked at the engine for a bit, and discovered SOMEONE had put the big end on around the wrong way... :( it had grooves so it could only go on one way, but someone still got it wrong.. :( lol
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cirvin
Nobel Prize Winner
USA
1542 Posts |
Posted - Jul 15 2003 : 3:10:17 PM
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No offense Aaron, but they discontinued breaker points on engines about 30 years ago. i doubt any engine has them anymore, and if it does, treplace the points with a solit state ignition. it is just that easy.
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Jul 16 2003 : 10:39:39 AM
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Many lawnmower type engines are still point type engines. It was only about 10 years ago that Briggs and Stratton switched to solid state ignitions. 9 times out of 10, a used engine that you will encounter is a points engine.
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cirvin
Nobel Prize Winner
USA
1542 Posts |
Posted - Jul 17 2003 : 10:44:20 AM
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My bad, misread the book. but still, don't replace the points, switch them out with a solid state system. it is more reliable and you don't have to replace parts. (unless it fails)
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Alien
Apprentice
Canada
149 Posts |
Posted - Aug 19 2003 : 10:01:37 AM
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I think the electrical is a-ok... I took the block apart and cleaned the whole cylinder and piston, had an inch of 'burnt oil'? and it now actually gave some signals of life... But after 3 seconds of boom boom bang it stops... I tried putting gas directcly in the carb to simulate the little pump that the newer lawnmowers have... Still same thing. I think it needs some fine tuning. Allso sometimes when i pull the cord it pulls it back very hard it almost broke my friends (FugitiveEagle)'s hand once...
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Andrew
13/m/Canada
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 19 2003 : 9:26:54 PM
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Sigh. You have to look at this logically.
First things first. You disassemble the block. Did you assemble everything properly with new gaskets, and all bolts to the proper torque? Did you shift the position of the piston rings at all? If you did, you will have to be careful and break-in the engine after you have it started. Are the valves adjusted properly? Do you have a repair manual with the proper procedures. If you just took the block apart then reassembled without paying attention to these things, you have damged a perfectly good engine.
Prove the the electrical system works. You need a spark tester to verify you are getting a good spark at the right time.
After that, we can begin to look at other systems.
I see from your signature that you are 13. That's fine, but it also means that I have been doing this since before you were born. So you might want to take to heart waht I say. 
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Kale
Nobel Prize Winner
Canada
795 Posts |
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Alien
Apprentice
Canada
149 Posts |
Posted - Aug 19 2003 : 10:58:33 PM
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Did you assemble everything properly with new gaskets: I put it back exactcly how it was but i didn't remplace anything, it seemes all in order, but i cleaned everything...
, and all bolts to the proper torque? Yes
Did you shift the position of the piston rings at all? If you did, you will have to be careful and break-in the engine after you have it started. What??
Are the valves adjusted properly? Not sure what you are talking about..
The engine didn't work from the beginning, so if i did any damage while taking it apart it wouldnt be such a big loss. But after i did this it did give some signs that it might work with some adjustments.
I don't know what you thaught i meant by that i took it apart but i only opened the front where you can see the piston, and where the spark plug goes in.
What else?? O yeah, why does it sometimes pull back hard??
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Andrew
13/m/Canada
Edited by - Alien on Aug 19 2003 11:09:22 PM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 20 2003 : 09:25:24 AM
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If you only removed the cylinder head, then you are probably fine. Just make sure to replace the cylinder head gasket (it's not cheap for what you get though...around $15-$20). And torque on these bolts is important. If it's wrong, the head will warp and you'll never get a seal...
Is this a point ignition engine? If so, then I am willing to bet that the reason it kicks back is because the condensor is dead. Briggs and Stratton lawnmower engines use breaker points that have an integrated condensor, so replacing the points should cure the problem.
HOWEVER, if you are attempting to start the engine without blades, then you NEED to install a set of blades. Standard lawnmower engines uses very light flywheels, and require the weight of the blades to balance the engine and serve as a "flywheel".
You're looking at an ignition problem.
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Alien
Apprentice
Canada
149 Posts |
Posted - Aug 20 2003 : 12:06:59 PM
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Ok, thanks Aaron i'll look intoo it today. I'm not sure that the points are, i'll look it up on the internet and tell you.
I didn't really understand what you meant. The engine will not work without blades? Because i took off the body and blade a long time ago...
Edit,
Didn't find much on the internet about points except a few pictures and i don't recognize them with anything on my engine. Basically what it is is there's 2 magnets on the side of the axel and i think there's 1 or 2 on the axel....Then there's a wire that goes to a button and then to the spark plug wich seems to give some pretty strong sparks since it paralysed my arm for 2 minuts while 'testing it' with (fugitiveeagle) my friend... As for the 'giving the sparks at the right time' i don't know...
Edit:
Actually it's the other way arround. There's 2 magnets on the axle and one (if its a magnet) arround it
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Andrew
13/m/Canada
Edited by - Alien on Aug 20 2003 12:15:48 PM
Edited by - Alien on Aug 20 2003 12:21:36 PM
Edited by - Alien on Aug 20 2003 3:19:01 PM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 21 2003 : 10:01:01 AM
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Go to the library. Pick up a book on small engine repair. There are many good ones.
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Alien
Apprentice
Canada
149 Posts |
Posted - Aug 21 2003 : 8:28:59 PM
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Yeah... I had a second lawnmower that we had absolutely no thaught of fixing. We didn't know what the problem was, but we knew it didn't make any compression. So we thaught it was dead... So we opened the head and the intake valve was rusted into the open position. After a few bangs with the hammer :) and a few litters of WD-40 :) we got it working and it actually started, but only with the fuel that i put directly in the carb, for some reason it wont take it's own fuel from the fuel tank, probably the carb is clogged, because i don't really see any other explenation. We're going to go to canadian tire tomorrow and buy some more DW-40 since we depleeted the supply, maybe a muffler since it seems clugged and old... And something to remove the rust that is still on the valve...
Andrew & FugitiveEagle
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Andrew
13/m/Canada
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Lawnmower engie won't start
