Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Flames shooting out of honda mower muffler


vwbr's Avatar
Visiting Guest

Posts: n/a

08-15-05, 07:50 AM   #1  
vwbr
Flames shooting out of honda mower muffler

My Honda Harmony walk behind mower is acting up again. This time I am getting flames shooting out of the muffler, and dark black smoke. It will take a good five minutes before I can get it running well enough to mow the lawn. Also I used to be able to finish the whole lawn on one tank, now it won't make it and I will have to fill it up again with fuel with abouth 1/8 of the lawn left to finish. Anyone with input.

 
Sponsored Links
puey61's Avatar
Member

Join Date: Apr 2004
Posts: 3,224
NY

08-15-05, 08:16 AM   #2  
Ignition igniter module. Pretty common on imports. A defective one will cause a timing problem and therefore black (rich condition) smoke and flames (retarded ignition timing) out the muffler.

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-16-05, 10:32 AM   #3  
vwbr
hmmmm, well I think I might have to take it in for repair this time.

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-17-05, 12:46 PM   #4  
vwbr
Well the repair guy said the carburater is shot. He changed the spark plug and got it running but said it might last only like 5 hours before it fouls the spark plug again. I can get a carb online for pretty cheap. Im wonder do the carbs come pre-set from the factory where all I have to do is replace it? Or will I need special skill to set it properly? Thanks

 
puey61's Avatar
Member

Join Date: Apr 2004
Posts: 3,224
NY

08-18-05, 08:31 AM   #5  
Is the replacement carburetor an exact replacement for your particular engine? Any carb for that matter will most likely be a non-adjustable anyhow. In other words, no adjustment will be required on your part. BUT, you want to make sure you get an exact replacement so that you don't run into any mounting problem issues. Furthermore, I can't see why you need to replace the whole carb when an inlet needle would likely take care of any trouble you have. But, bear in mind though that I don't have the ability of actually looking at the carb in order to make an educated diagnosis.

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-18-05, 11:49 AM   #6  
vwbr
Well the repair man said that you can't lean out these honda carbs. Once the carb starts going rich you have to replace the carb. And a rebuild will not work. And yes I looked up the exact model I have and the exact carb for that model.

 
puey61's Avatar
Member

Join Date: Apr 2004
Posts: 3,224
NY

08-18-05, 12:08 PM   #7  
I know Cheese will agree with me, but a carburetor won't richen on it's own unless there are adjusting needles whereas they back out from vibration. Which can't be your case since this is a non adjustable carb. They will however lean out due to gum/varnish build-up/accumulation in the passageways, in which case, a recon will be in order. If you, in fact, have a rich condition, then the most likely problem is a weak ignition problem whereas you don't have enough spark to burn off the fuel entering the combustion chamber. If you still WANT to buy the carb online, by all means, go ahead, but I don't think this will solve your problem. Remember though, that I don't have the ability to actually listen and diagnose your machine. My diagnosis is based on my 25-plus years in the OPE service industry along with your noted symptoms.

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-18-05, 03:47 PM   #8  
vwbr
Wouldn't the ignition module cause the problem all the time? Meaning when I put in a new spark plug it happens right away. I can get about 5 hours on a spark plug before it starts running rough. I only got the flames and black smoke as I was moving the throttle to full. Otherwise at full it will run fine, then kinda sputter, then run fine, the sputter agian. As it gets worse the time will between good running and bad will get closer. He said the valves were all seated properly and timed right.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,574
GA

08-18-05, 10:57 PM   #9  
I agree 100% with Puey61. I also think that you might solve your problem by simply replacing the air filter....even if it doesn't look bad. If the filter has ever gotten wet, oily, or just damp, it may not be allowing enough airflow past it and in effect, it's lightly choking the engine. The carb can't richen up on it's own unless an adjustment vibrates open (in your case, you haven't one), or the float needle quits sealing (which would cause the carb to drip all the time even when it is not running).

Another thing to look at is the choke to make sure it is opening all the way. I would set it at the throttle position you normally run it at, and then have a look at the choke. It may be that the cable is out of adjustment, and the choke is not all the way open when you think it is by the indication on the throttle control. Or it could be sticking. I don't think a new carb is the best answer.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-19-05, 07:21 AM   #10  
vwbr
Thank you all for your help. I went ahead and ordered th carb anyway, it was only $28. I am also going to get a new airfilter like mentioned. The guy explaned it that the metal inside of the carb is really soft and it actually melts away making the carb run rich? I dunno maybe he's blowing smoke, but the new carb was cheap enough, I'll let you all know how it goes.

 
puey61's Avatar
Member

Join Date: Apr 2004
Posts: 3,224
NY

08-20-05, 08:52 AM   #11  
Even if shipping is $20, you got a great deal on the carburetor. By all means, let us know the outcome once the carb is installed.

 
dave237's Avatar
Member

Join Date: Oct 2004
Posts: 255
NC

08-20-05, 06:17 PM   #12  
This very well maybe an over rich carb and I understand that your repair guy said your valves are good however, with flames being expelled from the exhaust after a warm up period; I would entertain the idea of the exhaust valve not completely seating due to heat expansion and the valve/tappet or valve/rocker arm not being correctly adjusted if only by (.001). This would explain the warm up period before itís acting up and also would explain the high fuel consumption. Iím extremely curious of the outcome of this post.

God Bless,
Dave237

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-25-05, 06:50 AM   #13  
vwbr
OK, got the new carb yesterday and just put it in. Started it up and it seemed to run well no flames or black smoke. It did miss a couple times. I did not get a chance to mow the lawn though to really test it out because we are in a hurricane, but after the hurrican passes I'll be able to see for sure. Interestingly the carb is slightly different and supercedes the old part number, so maybe there was a known problem in the old one.

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-28-05, 08:47 PM   #14  
vwbr
So I got to mow the lawn. It runs great under load, like when I am deep in the grass. But when its not under load like when i'm in the driveway, or when I lift up to turn, it goes and sputters, and will miss and surge untill it goes back under load and runs great again. I dunno, I guess I should be happy that I can get the lawn done now.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,574
GA

08-29-05, 01:49 AM   #15  
Did you replace the air filter?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
vwbr's Avatar
Visiting Guest

Posts: n/a

08-30-05, 11:00 AM   #16  
vwbr
Posted By: cheese Did you replace the air filter?
No not yet, but it looks pretty clean though. Think that will make a big difference? I'll change it anyway before the next mow.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,574
GA

08-31-05, 01:42 AM   #17  
I've seen (especially on hondas) perfectly good looking air filters that were restricted enough to cause the engine to run rich. This often happens after the air filter has gotten damp, then dried.

The guy telling you the metal melts away in the carb...well, blowing smoke is an understatement. Unless he's blowing smoke from that left handed cigarrette he must've been puffing on when he came up with that theory.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
vwbr's Avatar
Visiting Guest

Posts: n/a

09-03-05, 07:48 AM   #18  
vwbr
Posted By: cheese I've seen (especially on hondas) perfectly good looking air filters that were restricted enough to cause the engine to run rich. This often happens after the air filter has gotten damp, then dried.

The guy telling you the metal melts away in the carb...well, blowing smoke is an understatement. Unless he's blowing smoke from that left handed cigarrette he must've been puffing on when he came up with that theory.

Hmm you know.....come to think of it.....I did notice these problems starting after I had done a wash down of the mower. Maybe the filter got wet.

 
vwbr's Avatar
Visiting Guest

Posts: n/a

09-20-05, 08:42 AM   #19  
vwbr
Posted By: cheese I've seen (especially on hondas) perfectly good looking air filters that were restricted enough to cause the engine to run rich. This often happens after the air filter has gotten damp, then dried.

You got it, now with the airfilter change it's running at 100%. Wow it looked clean too, never thought the airfilter could have caused it to run so crappy. Well, its running great now, thanks all, for all the help.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,574
GA

09-22-05, 01:43 AM   #20  
Great! Glad we could help, and thanks for the update!


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Search this Thread