# small engine question - Lawnboy 10590



## wannabegreener (Jun 21, 2011)

Hi,

I just picked up a Lawnboy 2 cycle mower model 10590.  It is a little strange to me.  It has a gas tank and a 2-cycle oil tank.  It mixes the oil with the gas as it runs.  Anyway, it had been stored for about 4 years with no gas in it, but had 2-cycle oil in it.  I first tried to start it with fresh gas but no go.  I then took the carb off and it was real bad.  The choke and the throttle 'butterflies' were stuck.  I managed to get them free and cleaned all of the port holes and put it back together.  It now starts and will throttle up nicely but when running it a full throttle it suddenly dies.  If I kind of violently bang the mower up and down it will start up, but won't stay running at high throttle.  When it dies, it just cuts out immediately.

It's too late to try it now, but the only things I have read are:

1. it could be the vent on the gas cap is plugged so the tank is not venting.
  -- I would have thought that this would cause the engine to sputter then die, not just cut right out.

2. It is a mulching mower and rear bagger,  I have the mulching plug in but not the bag. The bag is at my mother-in-law's house (no pun intended).
  -- does the bag need to be on even when mulching.  I found a manual on line and it talks about some shut-off for the bagger.   I am able to start the mower without
     any bag on it, I just can't  keep it running.

Any help would be appreciated.  I need this mower for about 100 sq ft and don't want to buy new if I can get this one working.

Thanks


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## semipro (Jun 21, 2011)

Based on the "banging" that's getting it going your float may be sticking.  Actually, its not really the float but rather the needle that it connects to to control gas flow into the bowl through the seat.  Clean the needle and seat and see if that helps.


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## wannabegreener (Jun 21, 2011)

I had cleaned the float and needle valve every time I took the carb apart.  This morning I unscrewed the gas cap a little in case it was the vent, but really didn't think it was that.  It started on the first pull and I noticed that the plug to make it a mulcher was shaking. I tried to push the plug in all the way so it would lock in place but there was too much dead grass and dirt in the way.  I cleaned it up and then gave it a good boot and the plug went in all the way and locked into place.  I was then able to keep it running until I shut it off.  I thought it seemed like it was something vibrating loose when I got to high revs.  I'm going to assume it was the mulcher plug disconnect switch not being opened all the way.

Thanks for the suggestion though.

So this year is the first time I ever tried to fix small engines without any knowledge of what I was doing.  I used to just bring them in.  Well, I'm 2 for 3.  The first was a mantis tiller that I asked about in here that I got working.  The second was a 4 cycle mower that I could get running but not stay running.  I needed to get it fixed asap so I brought it in after trying for a couple of days.  I think I probably could have fixed it with the knowledge that I have now.  I think it was just a jet or port that was plugged.  I should have tried to shove a piece of wire through it to get it cleared.  Cost me $80 for that one.  The lawnboy is my 3 try and it's carb was really gunked up.  It had 2 cycle oil that had dripped in it and left for 4-5 years.  It now runs pretty good.  Can't wait to really try it tonight.

Love this forum


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## wannabegreener (Jun 22, 2011)

I may have spoke a little too soon.  The lawn mower worked for about 5 or 6 minutes then shut off again.  It started right up a couple of times, but barely idled.  Then it would not start so I just left it.  I only need it to do around a couple of trees with the mower.  I do the rest of the lawn with the tractor.  In the first 5 minutes, I was able to cut around 1 tree and was on my way to the second tree when it died.  I then used the tractor to cut the rest of the grass and when I finished, I went back to the mower.  It started right up again.  It ran for about 5 or so minutes again and then died and was difficult to start and then would not start.

I'm guessing it might be the magneto, but wondered if anyone with more knowledge had a more educated guess.

Thanks


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## heat seeker (Jun 22, 2011)

This is a classic symptom of an ignition coil going bad. Try this: carry a spare spark plug in your pocket. When the engine quits, immediately remove the plug wire from the engine's plug and put it on your spare plug. Ground the spare plug to the block, and check for spark. No spark = ignition problem. If you have a good spark, it's probably not an ignition issue. 

If you suspect a fuel problem, try this:
Take a can or jug, and remove the hose at the carb. Let it run into the jug for a while, to make sure you have free flow. You might have just enough restriction so the carb slowly runs out of gas. Not too likely, but possible. Usually a fuel supply problem will show up more quickly than your problem.

Maybe the quitting problem is why it got parked in the first place...


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## soupy1957 (Jun 22, 2011)

If all the above advice failes...............

Get a gun......shoot it...........and buy a new John Deere!

-Soupy1957


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## heat seeker (Jun 22, 2011)

soupy1957 said:
			
		

> If all the above advice failes...............
> 
> Get a gun......shoot it...........and buy a new John Deere!
> 
> -Soupy1957



Green for green, seems appropriate.


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## Adios Pantalones (Jun 22, 2011)

Even with a cleaned carb, you could have a sticky choke cable.


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## wannabegreener (Jun 22, 2011)

soupy1957 said:
			
		

> If all the above advice failes...............
> 
> Get a gun......shoot it...........and buy a new John Deere!
> 
> -Soupy1957



I already cut the rest with a JD.  I just keep ripping up the grass around two trees when I use the JD tractor.  Just trying to be a little more gentle in these small areas.

It is actually ok if it works this way. I cut the grass around 1 tree, cut the large areas with the tractor, then cut the grass around the 2nd tree when I'm done with the tractor.  I hate to buy a new mower for less then 200 sq ft of grass.  The tractor cuts about 1/3 of an acre so the mower coil has time to cool down while I use the tractor.

I'll try the spare spark plug to see if there is spark once the engine dies.

Not sure why it was stored or not used. It was given to me by my boss and he said it worked when he put it away 4+ years ago.  

Thanks for the pointers.


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## gdk84 (Jun 23, 2011)

I would try the ignition test to see if thats working properly. If all seems well than you can move on from there. Does it act like its starving for fuel? My guess is carb issue. From what you describe how gunked up it was to have the butterfly stuck shut im willing to bet there is more deposits somewhere. I had the same issue today with my weed whacker, wouldnt idle, wouldnt like any throttle at all. I ended up stripping the carb down to every last piece and cleaned everything. I found gunk in the pick up tube inside the carb. Cleaned and it took right off. Anouther thing to try is screwing your idle adjust srews all the way in and then back out. This will of coarse require re-asjustment of them, but sometimes it can clear any gunk built up. Just a thought... Todays gas stinks and make sure you drain all you stuff and run them dry at off season. Add fuel treatment to gas as well. My local small engine repair shop is super busy ever since ethynol has been around! Good luck!


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## wannabegreener (Jun 23, 2011)

gdk84 - what does starving for fuel feel like.  I won't have access to the mower for a week or more so I will check it and report back here after that.  

I would think that it it was starving for fuel it would happen before 5 minutes.  I'll get a better length of time that it runs the next time I'm using it.

Thanks for the pointers!


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## gdk84 (Jun 24, 2011)

Starving for fuel as some people call it acts just like described on your first post. Doesnt idle and doesnt like full throttle, usually just dies as you stated. This still could be the case even if it will run for a few minutes and then act up. If you feel up too it and have the patience, take the carb off and take it apart. Document all the parts so you know how it goes back together. I would buy some non chlorinated brake cleaner (doesnt eat rubber) spray into small container and let everything soak for awhile. Then use some light compressed air and dry everything. Inspect every part for gunk as you go through the process. You might put that back together and the thing comes too life... I know i do it all the time!


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## wannabegreener (Jun 24, 2011)

gdk84 said:
			
		

> Starving for fuel as some people call it acts just like described on your first post. Doesnt idle and doesnt like full throttle, usually just dies as you stated. This still could be the case even if it will run for a few minutes and then act up. If you feel up too it and have the patience, take the carb off and take it apart. Document all the parts so you know how it goes back together. I would buy some non chlorinated brake cleaner (doesnt eat rubber) spray into small container and let everything soak for awhile. Then use some light compressed air and dry everything. Inspect every part for gunk as you go through the process. You might put that back together and the thing comes too life... I know i do it all the time!



Right now the mower is at my mother in-laws house.  I won't be there for a week so I'll have to try it then to see what happens.  If it is not the ignition, then I'll bring it back home and let the carb sit in some cleaner over night.


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## mkt1 (Jun 25, 2011)

I had a lawn boy 2 cycle one time and would start then die a short time later, it was the muffler under the deck stopped up. removed the muffler cleaned it and all was well.


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## heat seeker (Jun 25, 2011)

M said:
			
		

> I had a lawn boy 2 cycle one time and would start then die a short time later, it was the muffler under the deck stopped up. removed the muffler cleaned it and all was well.



Excellent point! 2 strokes can't handle any exhaust restriction, so a clogged muffler or spark arrestor is a killer.


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## wannabegreener (Jun 26, 2011)

M said:
			
		

> I had a lawn boy 2 cycle one time and would start then die a short time later, it was the muffler under the deck stopped up. removed the muffler cleaned it and all was well.



Thanks - I did not remove the muffler.  Didn't even think about it.  I'll add that to the list of things to check.


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## wannabegreener (Jun 28, 2011)

ran the mower around both trees and it never stopped so I kept cutting.  managed to cut the complete lawn with it only stopping once and that was because I ran out of gas.  it usually takes me 50 minutes with a lawn tractor and using just the mower, it took me about 1:45.  I figured it would be a good test to see how long the lower would run.


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