OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters Whipper Snippers - AKA Line Trimmers

Interesting couple of hours yesterday with a couple of whipper snippers a friend of my wife brought over. First one he said needed a new primer bulb. Can't get one screw out to remove the carby so i could get to the primer bulb screws. Finally removed the screws but they had been Loctited in so one thread was stripped out. Then I noticed the fuel lines had pretty much disappeared and the strainer was in the bottom of the tank. Ok shake it out and half a tank of water poured out. The usual story "it was running" My standard reply to this is "I know it was running, they always ran when they left the shop" Anyway I got it up and running but the shaft wasn't turning, pulled the clutch housing and it was all rusted solid, makes you get very annoyed when people won't tell you the truth.The impression he had given me was that the primer bulb had only recently failed.The second one "just needs the pull start fixed because you can't pull it, it is stuck". My reply "Easy to see why it doesn't work,somebody put straight fuel in this 2 stroke, motor is siezed, nothing wrong with the pull start" " Can it be fixed" "Yes it can, take a grinder, cut the shaft in half and drop it in the rubbish bin". Thought I would give you a bit of a laugh for the morning

That sounds typical...They think we are miracle repair shops. The customers want it fixed for nothing too because they didn't pay much it in the first place. Certain brands and models I don't even take in anymore.

Sounds about like my day yesterday when I tried out a 3/8 lp carbide chain for stump cutting. It supposedly one that the fire and rescue departments use. What a disappointment and I couldn't sell it for this purpose with any integrity.

I knew was to be a little slow but when comparing to a regular chain it like putting the chain on backwards. No way I can cut the 30 stumps I got with it. I just use the regular even if I need to put several chains.

The thing with the carbide chains is they can never be as sharp as the standard ones, that is why they are so much slower. Carbide while tough as far as wear goes is also brittle hence you can't put as fine an edge on them.

Not sure why people insist on wanting me to look at their whipper snippers, I tell them I hate them and I'm not interested in wasting time on them , but I get this typical reply "well would you just have a look at it anyway?" to which I usually reply "I'm looking at it now and I'm still not interested". Problem is I usually give in and now I'm ending up with a growing pile of whipper snippers and I'm beginning to forget who belongs to what. Carbies seem to be the greatest issue with all there small 2 strokes

Lack of use kills Zamas. Walbro fair better in my experience. Not sure about Tillotsons.
I think it's just general lack of care. I am guilty myself. I never changed the foam air filter element in my Mitsubishi TU26 engine on my weed whacker for it's first seven or so years (albeit used infrequently) and when I finally decided it was time to check how dirty it was, it fell apart in my fingers. Lucky a piece wasn't sucked in during use.

Mowerfreak, I would think that lack of use and leaving them with fuel in them is probably the cause of failure of 98% of them. The other 2% is from people not using 2 stroke fuel in them

Most times, not always, I empty the fuel into another machine that takes 25:1 fuel (all my machines!), use it and what remains, I empty into a bottle to use in another next time. This system of mine minimises stale fuel and stops fuel evaporating in the tanks while in storage, and leaving too much 2 stroke oil in the remaining fuel.

Add to that, owners using 91 octane number fuel, or even worse, the E10 version, for their 2-stroke mix; then leaving them in the trimmer's tank!

These petrols have the shortest shelf life, at least of those on the Oz market. And then of course, there are the side issues with E10...

ATM my only operational two-stroke is a 1970s Echo CS601VL chain saw - and I commenced emptying it of fuel after every use, after leaded Standard petrol went off the market. Still runs just fine, on fresh 20:1 BP 95 Premium petrol/Castrol TT oil mix.

I don't complain as it is repair work.

Users usually are too be of a hurry when putting away their equipment. On top it the equipment might for a year or more between uses. As the fuel mix nearly everything here now uses 50:1 mix. I still use a multi-mix synthetic oil with stabilizer as I do still get in antiques that need as much as 16:1 mixes. Usually go through about 5 gallons a year in the shop.

Just got in a pole saw yesterday. Customer said just needed fuel lines. Funny it needed those plus a metering diaphragm with gasket and internal fuel strainer. Good thing I keep these in stock.

Kinda nice to have though as I had a storm just pass through and blown a tree down on my fence for the chickens and emus. Luckily I had the 2 emus in a second pen at the time. That pole saw got a good test run. Oh, how convenient to just get one in the shop. One draw back now I got to sharpen the chain. That something I got find in bulk chain which is a chain with the bumper links. Probably will need an Oregon or Stihl chain.

Plenty chainsaws so I it wasn't that I struck without a way to clean up the tree but I do think that 88cc with the 36" bar would have been a little over kill.

Spot on.
Where they really shine is in cutting very old, very hard timber. Like the teak pilings and timbers under many of Melbourne's older wharves - Melbourne Ports were an early user of carbide saw chains.

What did surprise me is how well an old carbide tipped masonry drill went through hardened steel even though compared to a normal HSS drill bit I couldn't get a really sharp cutting edge on it.

I found out what my problem was. I had brought a flat grind carbide when it should been hooked like regular chains so it would self feed. They just don't make one in 3/8 lp but my bigger saw uses a .325 so I will order one a little later after I get over the Spring start costs of the business.

I over the years chip a few teeth on circular and table saws but most times the carbide tipped blade just goes right the nails without problems.

Hi AVB with these whipper snipper type carbs what is it in them that obviously gets blocked, usually I just fit another new carb but curiosity is getting to me and I want to know what makes them work

Really depends which carb as to what can get clogged.

Here is some basics.

1. 
   [1]Metering diaphragm hardens.
   [2]Fuel pump diaphragm hardens.
   [3]Then the metering passages clogs with old fuel and trash. These are usually behind the mixture screws.
   [4]Filter screen clogs. Note: many of newer have a filter can clogged even it looks clean. Can not be clean, replace only.

Do not use tag wire or similar item to probe holes as some are check and are easily damaged.

Use only an Ultrasonic cleaner with soap and water to clean these. Carburetor cleaners can damage the internal check valves.

Also when replacing the needle and lever it must be set correctly; or, flooding or lean condition can occur. This one gets a lot of home mechanics.

On carburetors which depends on type even the nozzle can get clogged.

Some of these carburetor are so cheap now that even the repair kit is about same but others it well worth learning how to clean and rebuild. There is also carburetors that parts are not even available for now.

Thanks for that AVB, I have been able to get through life so far without an ultrasonic cleaner but I guess I will have to get one now because I keep getting people asking if I would please look at them, basicly I hate them but I keep getting suckered into people leaving them here. What wattage cleaner would you suggest

No need to go overboard on wattage Norm, I find that one of the little Aldi 600mL/50W [input power] units works OK for small Items. Specs, watches, small carbies etc - I've actually got some rifle cartridge brass in mine being cleaned of tarnish, right now.

The thing to realise is, you're not necessarily limited to just the sizes that will fit in the bath itself - it's possible to use a taller plastic container. 'Flexible' containers like milk or bottled water bottles work best.

You just stand it in the bath, fill up with your water-based cleaning solution, and fill the bath around it with plain tap water.

If you do decide on a more powerful/bigger tub unit, Jaycar Electronics sell a 2.5L/170W one that's good value.

Thanks Gadge, I'll have a look and see what I can pick up

As Gadge said you can make do with a small unit, preferably one with a heater to heat the solution. Most of the cube carburetors will fit. I did my work with a 2.5 Liter unit for several years just had to deal that short timing period. My business lead me to larger carburetors and the need to let the unit sit unattended for longer cleaning periods so I upgraded to 6 liter unit that way I can cleaning a carburetor while working on another project plus I now have adjustable heated water temps. Most of my small carburetors including ATV carburetor fit in it.

This was what I was doing Saturday here. I set a 30 minute cycle while taking care of customers that swamp me. All week no customers then Saturday they came from all directions. I even had one to show up Sunday @ my home. Not going to be able to work on it until probably Wednesday as it going to be raining for tow days here. I got a $350 carburetor that going to need a bushing machined for it. The choke had worn complete in two. Now I got to enlarge the shaft hole and install a bushing. Still cheaper than buying that expensive carb.

As for cleaning just beware to more crowded the tank is less effective it is. Also those plastic baskets will absorb about 20% of your cleaning power. Personally as starter unit I would recommend starting with a 2.5 liter with heater. Another trick to save on the expensive solutions is place items in a smaller sealed or unseal (depends if taller than the rest of the tank's solution or not) container with the solution and fill the tank with plain water otherwise. Personally I usually clean with household liquid dish and water. I do have stronger soaps pH wise but don't use them much unless I planning to store the carbs for a while as they non residual soaps. With regular soap you need to do a rinse cycle using plain water and lightly blow dry the carbs being carefully not to blow out any of the check valves.

This what I did and then when I got ready to upgrade I sold the 2.5 liter (well taken care btw) for 50 % of what I paid for it to another start-up tech and applied that to the new unit's cost.

Final pieces of advice don't mix incompatible chemicals in the unit as some can damage the tank and carbs themselves plus some can produce toxic fumes. Also don't let the cleaning solution just sit in the unit as some tanks even when they to stainless steel (very low grade of stainless steel) will rust. My 2.5 liter tried to but I caught it in time to remove the rust. Another thing to preclean the carburetors by removing all the loose exterior surfaces. You don't want trash migrating into carb that you can prevent.

NormK,

These whipper snippers (string trimmers to me) are not as bad as you think once you get hang of repairing them. Just apply what you know about 2 cycles to them. For me had learn on the fly with no basic knowledge of 2 cycles when I started; only had worked on 4 cycles before. Being patience is key to working on these.

What help me was time and a truck load of thrown away trimmers. I ended fixing nearly 3/4 of them and sold them. No great profit other than learning experience I received. No great lost other than my time and parts used during the learning process but being able to sell few sure didn't hurt. When I first start it could take me all day on what now is a simple 30 minute repair.

Just beware the replacement vs repair cost. If the repairs here exceeds 50% of the replacement cost then usually not worth fooling with. Other words those use it and throw away with broken trimmers are just that.

One thing to remember too is unlike other two cycles that you're familiar with you will at least 110 psi compression for one to start most times though I have seen a few that would start @ 95 psi. Even then they don't work very well.

My 31cc Ryobi (engine by Ryan of the U.S) string trimmer registered 120 psi on it's compression test and the performance reflects that (not to mention sound!).