Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Spring is almost here, and we been getting quite a few 60F plus days.  While waiting for the last snow storm/blizzard to arrive before preparing the snowblower for summer and fall hibernation, I thought I get in the spring cleaning mode and get my lawn equipment up and running. 

Besides getting new fuel lines, fuel filter, air filter, and a new spark plug, what is the proper way to service a diaphram carburetor?  What's involved?

Also, I need a new bump feed head.  Any recommendations on the quick and easy loading heads from Stihl, Shindaiwa-Echo brands?

aa335:

How old is the machine?  

Call me old school but when it comes to small two stroke OPE engines, all I do is clean the spark plug, air filter and make sure the screen in the exhaust is either cleaned or preferably, removed.  If the fuel lines look good and the filter is passing fuel, don't bother with them.  I've got 30 year old equipment with small two cycle engines running on original fuel lines and some are even still running with original plugs.  Two strokes are pretty simple.  If you keep your fuel clean, air filter, spark plug and exhaust clean during the season, chances are it will run very many years without problems.  One tip I'd like to offer is to run Seafoam through your fuel system.  I usually mix about four oz. to two gallons of two cycle fuel.  That will last most of the season.  Second tip:  If the carb's doing it's job, don't mess with it.  If it is malfunctioning, you'll have to buy a rebuild kit for it which is usually a couple of diaphragms and a spacer or two.  Be very, very careful during dis-assembly.  Some of the small diaphragm carbs have tiny spring(s) in them that seem to evaporate once the carb is opened up.   One other thing to watch for is the throttle cable.  Make sure it's not binding anywhere and ensure that it moves freely.  If it's stiff, put some light machine oil into the cable.   Finally, if you have an access port for adding lube to the trimmer head gear drive, you might want to check and add some lube if required.   

Regarding the trimmer head.  I bought an Echo a few years ago that uses two ten inch pieces of fairly thick line that fit into a locking cam.   They are pretty much bullet proof but do require fairly frequent changing if trimming along concrete surfaces.  I usually pack half a dozen or so in my pocked if I'm doing around the house and along the curb which is probably five hundred feet or so.  I usually buy a big roll or the correct diameter string then cut a supply of pieces to last the season.         

borat wrote:

The string trimmer is a 4 stroke that's about 10 years old.  The fuel pickup line is crumbly and the filter is coated with slime.  The fuel pickup and return lines was replaced with a silicone fuel line.  The fuel filter was replaced as well.  The plug is dirty but I havent replaced it yet.  I thought I should get my fuel system sorted out before dirtying a new plug.  Starts up after 2-3 pulls and runs steady on idle after it has warmed up.  Throttle is now responsive and the engine no longer stall out at full throttle.  From your suggestion, I should leave the carb alone since it seems to run normally. 

What is SeaFoam?  Is that a fuel preservative or a carb cleaner?  How do I use it to clean a diaphram carb?  I'm currently using Sta-Bil on my OPE because that's the one I'm familiar with.  Have not come across SeaFoam at the stores.

aa335 wrote:
Sea Foam: http://www.seafoamsales.com/motorTuneUpTechGasSmall.htm

Try NAPA if you have one near you, the ones around here stock it and other people on the forum have mentioned they get it there also, so maybe they all do.

Thanks Bill_H for the Seafoam application link.  From the quick read, SeaFoam seems like an engine tune-up in a bottle. 

I'll look for it at auto parts store and give it a try.

aa335:

You're obviously on the right track changing fuel lines/filters that need it.  If the carb is working fine, don't mess with it.   Chances are that it's not in that much of a need for dis-assembly to clean it.  A season of using Seafoam will take care of that. 

I used to use Stabil up until a few years ago when I found a bottle in my garage that had turned to a gel.  It wasn't even a year old.  Ever since then, it's been Seafoam all the way.   I went on an engine tune up/cleaning spree a couple of years ago.  All two stroke engines in a couple of chain saws, brush cutters, outboard motors and a four stroke lawn mower.   The effects of additives such as Seafoam etc. are difficult to measure.  I have found through experience that often, there will be no change in the engine's performance.  Understandable if the engine is well maintained and in good running order.  However, I did notice a considerable improvement in a 25 year old  Tecumseh two cycle engine on a Jiffy ice auger.  It had not seen much use and when I fired it up, it wouldn't rev out well, and overall ran poorly.  I put a full oz. of Seafoam into half a quart of fuel and ran that through the engine for a while.  It smoked quite a bit for a while, coughed and sputtered as per how it was running.  After three or four minutes, it began to smooth out and within five minutes, it was running like new.  That confirmed to me that the Seafoam actually works.  Now I run a bit of it each year through all of my engines.   I use a bit of a stronger mixture in my two cycle mixed fuel just to keep fuel systems in good shape.  It also works well for taking water out of fuel.   I run it in my car, truck, and eight motorcycle engines from my six cylinder liquid cooled Valkyrie to my single cylinder two stroke dirt bike.  Not saying that it's just because of the Seafoam but everything is running top notch.    

borat wrote:

Sounds like a good practice for preventative maintenance on OPE.  I would use SeaFoam periodically on the string trimmer since the diaphram carb is a polymer.  I don't want to quickly deteriorate it by using too much of cleaners of any kind.  You are correct, a well maintained and good running engine does not see much improvement in performance since fuel additives are not power boosters.

I'm hesitant to use SeaFoam in my car though.  There is so much emission control and computers that it may throw a diagnostic code.  I don't tinker with new car engines with OBD-2 since it is beyond my knowledge. 

I treated a 02 VW Golf with a gas engine. The car had about 150 000 km on it. I did the gas tank, air breather and brake booster. Smoked a lot. I tend to drive like an old man suffering from motion sickness, so my car was gunked up. I was amazed. Not a subtle increase in this and that, the engine ran like it did the day I bought it. I was skeptical about sensors and everything, but I never had a problem.

I don't know why more people don't use it.

aa335 wrote:

If you read the instructions on the can, I believe it states that is "oxygen sensor" safe.   I wouldn't worry about the polymer diaphragms either.   The mix ratio is pretty low. 

Seafoam has been around for a long time.  It's been a well kept secret and is not as readily available as Stabil.  Do a little research on it.  You'll be surprised how many people swear by it.

JohnnyBoyUpNorth wrote:

How long have you been using Seafoam Johnny?

JohnnyBoyUpNorth wrote:
Never had a problem with carbon build up on my car.  I let her breathe all the way to redline and stretch her legs daily.

borat wrote:
Yes, I did caught the oxygen sensor safe part.  I'm a little cautious since the car has more sensors than I know about.

I started using it when I was about 12 years old with model airplanes, so that would be about 23 years. I use it mostly as a penetrant. For this purpose it almost works too well; I've seen it loosen up punky welds when they were warmed up with a torch.

I've used it as a cleaner for my old ATV prior to opening the engine case and I've seen the before/after with it. It cleans so well that I am scared to run fresh oil in my engine after using it. I'll have some sacrificial cheapo oil to run an hour, then drain/fill again with the good stuff.

I always keep a stockpile of three or four cans. My opinion and vote is worth as much as any man's, and I swear by this liquid.

JohnnyBoyUpNorth wrote:
I have a glow plug .21 engine which hasn't been run for a while.  The inside may be gunked up a bit.  Do you think I can use SeaFoam on it?  I got too many things to do at this point to take apart the head and clean out the crankcase.

It's been a while, but I used to soak the whole engine in Seafoam. I'd take the fuel lines off, and turn the engine to bottom dead center.

It should work just fine. Scrape it as best you can, then fire it up. You might want to have a spare glow plug handy.

Re: "SeaFoam" and Gas String Trimmer tune-up.
Curious as to what this SeaFoam "miracle product" was all about, I checked into the ingredients by looking up the manufacturers mandatory MSDS (Material Safety Data Sheet) on this product.  I found that it contains:  "Pale Oil" 40-60% (by weight), "Naptha" 25-35%, "IPA" 10-20%.  "Pale Oil" is simply another name for common mineral oil, the same stuff that is found in most engine oils (without the additives).  "Naptha" aka VM&P (Varnish Makers and Painters) naptha, is what is more commonly known as "gasoline" without the additives, aka "white gas".  "IPA" is simply Isopropanol which is more commonly known as Isopropyl Alcohol or "Rubbing Alcohol" (diluted).  All the "degumming" and cleaning effects of this compound can be attributed to the solvent effect of the naphtha and the Isopropanol.  Obviously, since your gas tank has a copious amount of gasoline already in it, adding more is not likely to accomplish anything.  The real solvent effect is in the Isopropanol which in 10-20% concentration, is likely to have little solvent effect upon gum, varnish, and other petroleum oxidation products unless you use it "straight".  Currently, most "oxygenated fuels" contain around 10% Ethanol (another alcohol) which is also an excellent solvent.  So adding more alcohol to fuel that already contains another form of alcohol is not likely to be particularly beneficial.  Also, there are many anecdotal accounts of small engine repairmen blaming the deterioration of internal carburetor rubber diaphrams and other such parts, on the effects of alcohol and other additives in current gasoline formulations. 

The best way that I know of to properly service a diaphragm type small engine carburetor, is to buy a carburetor rebuild kit and rebuild the carburetor.  The necessary tools are minimal and the only other thing required would be instructions (see your local library), and a can of carburetor cleaner from your local wally world or auto parts supplier.   A wrench to remove the carburetor, and a couple of screwdrivers to disassemble the thing is usually all that is required.  The diaphragm in a small engine carburetor acts by using crankcase pressure pulses to pump gas from the tank to the carburetor.   They are thin and really flimsy.  They also do not last forever.  Good luck.

Interesting observation rktc. 

However, I'm wondering if "every" ingredient in Seafoam is listed?   Seafoam is also used as a very good fuel stabilizer.  Which of the ingredients you listed would contribute to that function? 

From your analysis, one would conclude that you don't believe that Seafoam does what it claims to do.  Would I be wrong in making that assumption?   If so, it would appear that myself and many others have been duped into believing that it actually works.  I know I've run Seafoam in a number of small two stroke engines with no particular remarkable observation of improvement.   That might be partly due to my steadfast regular maintenance and the moderate use of Seafoam on a regular basis on machines I'm always using.  

Now, I do have at least two small engines that I hadn't used in many years and they had never been treated with Seafoam.  One engine was a small Tecumseh two cycle  mounted on an ice auger.  It had sat unused for at least ten years.  I recall that it had run pretty lump when I put it away.  Probably why I quit using it.   So, one day when I was giving my OPE the Seafoam treatment, I pulled down the Tecumseh engine, clamped it down on a WorkMate bench and  put in fresh fuel.    After a considerable amount of effort, It fired up and ran lumpy as usual.  I poured about an ounce of Seafoam into the fuel tank and within a minute or so, the engine began to emit very thick blue/white smoke.   Far more than normal for a two cycle.  About two to three minutes later, the smoke had cleared up and the engine was responding to throttle input crisply and idled down very nicely.  I can't make a definitive scientific conclusion that Seafoam is what cured the engine's ailments but I can't think of anything else that would have done so. 

I was so impressed with the results I got with the ice auger engine, I decided to pull out an old 1976 Johnson 15 h.p. outboard engine that I had retired for being down on power and difficult to start.  I had bought it used and don't know it's history.  I do recall that it was down on power in a big way.  I used to put the Johnson on a very light 14' aluminum boat for my young 12 year old nephew to use.  A kid down the lake had a new Yamaha 6 h.p. engine that would run neck and neck with the 15 Johnson.  I recall that I had spent numerous hours cleaning and adjusting the points, putting in new plugs, cleaning the carb probably five times and with virtually no improvement in performance.   After my nephew grew into his teens, he no longer used the 14' with the Johnson so that motor was retired to the garage about 15 years ago.   After the Tecumseh engine revival, I gave the old Johnson the same treatment.  This time, I set the pistons so that I could pour in Seafoam to let is sit in the cylinders over night.   The next day, I mounted the engine on a 45 gallon drum half full of water, put in some fresh fuel and struggled to get it running.  It fired up and ran as it normally did but puking out a thick cloud of blue/white smoke .  It  idled fairly well and would rev up sluggishly.   I added a good dose of Seafoam to the fuel and got more smoke for a few minutes then it cleared up.  I put the motor on the same old aluminum boat, added more fuel and Seafoam to the tank and took it out for a test ride.  The engine ran better than normal and would occasionally, emit  the occasional puff of heavy smoke.   I'm not exaggerating,  after five minutes or so, the performance improvement was remarkable.   It spins up to maximum rpms quickly and actually makes power much closer to a 15 than a six.  Again, I have no scientific proof that Seafoam was the ingredient that brought power back to this engine.  I do know however ,that the engine makes noticeably more power than it ever did before the treatment.   My assumption is that the rings were probably carboned up and the Seafoam may have freed up the rings to improve compression.   

In summary, I do not challenge your analysis of Seafoam ingredients.   If your intent is to dispute the effectiveness of Seafoam, I cannot scientifically prove that you are wrong there either.  On the other hand, from observations of my personal experience with many years using the product, I have no intentions of stopping use of it any time soon.