Sticky valves?

[Woody71]

Hi All,

I have a Toro 20007 mower with a Tecumseh LV195E engine. I started noticing missfires and then a gasoline smell in the oil.

It's been running with fresh SAE 30W oil since May and fresh gas with STA-BIL. Spark plug and filter were both changed in may as well.

Person at the mower shop suggested that the a carb cleaning/replacement part kit would probably clear it up. Had this done and it does the same. Then I started thinking possible sheared flyweheel key because when I sharpened my blade in May, it almost came off because I didn't torque it down tight enough (I've not hit anything that would cause the key to shear).

Mower shop suggested I bring it back up when I said it was still missfiring after the carb tune up. I ran my theory of the flywheel key by the mechanic and he said it did sound like the timing was off.

Called today asking about my mower and the mechanic came on and said that the flywheel key was fine and that they went through the carb again and all checked out. He said the missfires were "Nothing to worry about". When I picked it up he said that if you start looking into valve replacements you're getting in the 200+ dollar range and I won't put any more $ into this mower as it's from 2007.

Although my first batch of gas this season had STA-BIL, I put Sea Foam my second can that I filled up a couple weeks ago.

So based on what the mechanic said, about the flywheel and carb checking out, is it possibly that Sea Foam may correct this after running it through the engine for a month or so? Or am I looking at living with these missfires until this think dies?

Any suggestions are welcomed. I'm not afraid to get my hands dirty on this, the only reason I had them do the carb tune is because I had a lot going on and had never done it before so I figured let a pro do it.

 

[eljefino]

I suspect an ignition problem more... like a tired coil.

A carb issue would run variably badly with moments of acceptable.

 

[FNFAL308]

If the valves are sticking SEAFOAM may help..

Doubt it's a Coil issue, usually these coils either work or they don't.. IE: Ya either have spark, or ya don't.

I would still be suspect of the Carb and wonder what they checked? These carbs have a couple prob areas.. One being the "O-RINGS" on both ends of the emulsion tube inside the carb. These go bad and need to be replaced.. If bad sometimes the unit will run but it surges. There is also a very small (oft missed) hole in the main jet. If this small hole is blocked it will cause a miss or surge.
Also check the SIDE of the carb and see if there is still a small black plug in it? "IF SO" remove the plug, there is a jet behind it that is also often missed. Pull this jet, cean it and try shooting some carb clean into the hole while the jet is removed.

The carb kit for these is cheap and pretty easy to install although replacing the needle seat can be tricky w/out a pressure tester..

 

[hate2work]

Misfires, by definition, are spark related. So if this is really a misfire, your carb has nothing to do with it. Your carb can run lean, run rich, surge, flood, etc., but it can't cause a misfire.

Typically, these electronic ignitions either make spark or they don't. And it's hardly ever the coil itself, it's almost always the module. Keep in mind that many modules these days are built into the coil. Good that you ruled out the flywheel key.

I'd guess that 99% of the misses I see are either related to the coil wire/boot, or due to carbon deposits flaking off the piston and attaching to the plug electrodes. I'm seeing that ALOT with people who have switched over to syn oil in their gas on these two strokes. I realize this is a four stroke engine, just thought I'd mention it. Easy to tell, just look at the plug for deposits.

Good luck-

 

[FNFAL308]

Quote:
Misfires, by definition, are spark related. So if this is really a misfire, your carb has nothing to do with it. Your carb can run lean, run rich, surge, flood, etc., but it can't cause a misfire.


By definition this is true.
However more often then not the complaint is mislabeled.

As I mentioned above these coils either work or they don't. If the coil makes spark, the spk plug has been replaced, and the flywheel key is not sheared there aint nuthin else to cause a "misfire" in it's literal definition..

Hence my being suspect of the complaint and noting the issues with these carbs.

 

[Woody71]

I forgot to run this by the mechanic this afternoon. When I pulled the engine cover and shroud before taking it back up there, I noticed a bit of surface rust on the coil. Would just the rust alone be enough to cause a missfire?

The carb tune up I had done included the carb kit, I'm not sure exactly what else was done in regards to cleaning. Videos I've seen of doing a carb clean involve removing the engine cover to completely remove the carb. When I went to remove the engine cover after I picked it up last Sat., there was dried grass caked on a couple screws so I don't thing it was ever removed.

Suspecting the plug, I replaced it before I had the carb cleaned with the same results. A friend did mention that it could be a loose connection where the boot meets the wire and as far as I can tell, it's part of the module and I can't replace just the wire.

 

[TFB1]

Originally Posted By: FNFAL308

As I mentioned above these coils either work or they don't. If the coil makes spark, the spk plug has been replaced, and the flywheel key is not sheared there aint nuthin else to cause a "misfire" in it's literal definition..

Hence my being suspect of the complaint and noting the issues with these carbs.


On the solid state type even if the flywheel key is sheared, it won't cause a loss of spark, just will be out of time... The old points type ignitions would loose or maybe have weak spark because the timing of the flywheel-coil in relation to points operation was incorrect...

If it's a actual misfire, possibly the coil to flywheel gap needs adjusted...

 

[FNFAL308]

Originally Posted By: TFB1
Originally Posted By: FNFAL308

As I mentioned above these coils either work or they don't. If the coil makes spark, the spk plug has been replaced, and the flywheel key is not sheared there aint nuthin else to cause a "misfire" in it's literal definition..

Hence my being suspect of the complaint and noting the issues with these carbs.


On the solid state type even if the flywheel key is sheared, it won't cause a loss of spark, just will be out of time... The old points type ignitions would loose or maybe have weak spark because the timing of the flywheel-coil in relation to points operation was incorrect...

If it's a actual misfire, possibly the coil to flywheel gap needs adjusted...


If the flywheel key is sheared this is true.. I've seen them out of time bad enough that the engine will pretty violently "snatch" the handle out of your hand when you try to start it.
I work on this stuff everyday, since the unit in Q was well noted I didn't reference the old style points ignition since it doesn't apply here (or pretty much anywhere anymore)..

As far as the AIR GAP goes that's easy to check.. Remove the spk plug and blower housing.. Then rotate the eng until the flywheel magnets are inline with the coil pick-ups.. Slide a Business card in the gap and your GTG. IF you can't do this simply loosen the two coil bolts, reposition the coil so you can slide that card in and retighten the bolts.
While it is important to have the air gap correct, on these engines a couple .002" either way won't really matter much..

Generally speaking a TRUE "MISSFIRE" will be ignition related. There are few "ignition" related parts on these engines. If the ignition has been checked and is said to be fine, then it's either not a True Missfire, OR the problem was misdiagnosed.

While I'm not questioning whether or not the OP has a Run Issue I am suspect of the shops diagnosis. These engine's aint nuthin fancy. They have some known problems but are pretty easy to diagnose.. My intentions are to offer some insight and nothing more. It's just as hard to "FIX SOMETHING" over the Internet as it is to fix something over the phone..

With that being said there is a wire from the engine stop/flywheel brake to the coil.. I suppose it;s possible this wire could have a bare spot on it that occasionally touches the eng and shorts out the coil.. If one was so inclined the Air Gap and this wire could be checked at the same time..

 

[hate2work]

Originally Posted By: FNFAL308
It's just as hard to "FIX SOMETHING" over the Internet as it is to fix something over the phone..

Nope, it's much harder on the internet, because on the phone at least you can talk directly to the person, on the interweb all you have is what he has written. Kudos to you for trying

 

[Woody71]

In regards to checking the air gap with a business card, the distance between the flywheel and coil pickup is much greater than the thickness of a business card. Is this gap on the solid state module itself?

 

[FNFAL308]

Originally Posted By: hate2work
Originally Posted By: FNFAL308
It's just as hard to "FIX SOMETHING" over the Internet as it is to fix something over the phone..

Nope, it's much harder on the internet, because on the phone at least you can talk directly to the person, on the interweb all you have is what he has written. Kudos to you for trying

Thanks, & Kudos to you as well, your on here trying to do the same thing..
Your right it's difficult at times to interpret someones written (typed) words.. I suppose at times it's just as difficult for someone to interpret mine..
On the phone you do have a direct connection but it's funny sometimes the things peeps ask on the phone..

I always like the Customers that call asking for a "BELT" or a "BLADE"..
Customer: "Yea I need a Belt for my Mower, you have belts there?"
Shop: "Yea we have belts, what kinda mower ya got?"
Customer: "It's a MURRAY, I just need the belt".
Shop: " I need the Model # & Ser# of your Mower please. Also need to know "Which" belt and your Deck Size"?.
Customer: "WHY do you need all that, all I want is the belt. Aint they al the same"? "Where is the Mod# & Ser# located, I can't find it anywhere"

 

[FNFAL308]

Originally Posted By: Woody71
In regards to checking the air gap with a business card, the distance between the flywheel and coil pickup is much greater than the thickness of a business card. Is this gap on the solid state module itself?


Ahhh, no it's not..
.010" is pretty much the norm.. A Biz card will go .010"-.015" and works just fine in a pinch.. Since many don't have or know how to use a feeler guage this is an acceptable method.. In fact a pc of cardboard (much like a BIZ Card) is sent along W/A new TECH coil to set the Air Gap with..

 

[TFB1]

I set the last one I installed by using a doubled over blue paper shop towel... I'm guessing compressed it's a little less than .010...

 

[Woody71]

So I just got done mowing the lawn. The manual for my mower says to run a garden hose in front of the right rear wheel to clean the clippings from the bottom of the desk while the mower is running. I did this and during the process, the mower bogged down and then finally shut off. I didn't spray water anywhere else.

Is this something that I just have to give it some time to dry out and then it will start again?

 

[Woody71]

Never mind my last post, it ran out of gas while I was rinsing the bottom of the deck. Didn't think to check that as the tank appeared full before I started mowing and I generally only use 1/2 tank per mow. Amazing what a full tank of gas will do for starting issues.

 

[FNFAL308]

In my Very Best SLINGBLADE voice:

 

[Woody71]

Yep, When I came back in the house after filling up the tank, I said to my wife "as Carl from Slingblade said 'It ain't got no gas in it . . .mmmm hmmmm'" Great movie.

 

[Woody71]

I did some more digging on some of the gas/oil treatments. One source indicated that when valves are out of adjustment or stuck, it can cause a rattling noise.

My engine has been doing this for quite some time now, more so when I'm going into longer, wetter grass. It will rattle for about 10 - 15 seconds and then the rattling will stop and the engine goes back to normal operation. I figured it was grass getting deposited on the bottom of the deck. The blade is tight, straight, sharp and the crankshaft is not bent.

That said, I'm going to put some SeaFoam in the oil (it's already in the gas) and see what it does. If it doesn't correct it, chances are I have a problem that's not worth fixing unless it's a simple valve clearance adjustment.

Oil/additive related question: I'm using Peak SAE 30W motor oil that has a detergent/cleaner. Would it be overkill to add SeaFoam? Also, if I were to go with SAE 30 non-detergent, would SeaFoam add the detergent? My mower manual says to use an SAE 30 grade with detergent.

 

[steve20]

Woody---hire a lawn service !!! j/k

 

[Quest]

YOu are making the situation worse, Woody.

It's just a very crude engine that doesn't have to run up to the precision of an OBD-II water-cooled automobile engine ignition timing and such.

Just run it and enjoy the mow, and get rid of it when you become sick and tired of it (maybe 10to 20yrs down the road?!)

I know I would, for I'm still running my 16 yr+ B&S 4hp quattro engine that doesn't burn oil and pretty much uses anything I dump in it: from doped (B&S fuel stabiliser) gasoline to slightly used german castrol 0W30 in the crankcase, etc. that darn thing hasn't miss a single beat yet.... Do I care if I die? nope. Would I bother to spend an extra 100bux to get a small engine shop to do tuneups on it?! nope (I can do it myself).

Q.