View Full Version : what i learned this weekend.... weed trimmer repair.


petee_c
05-13-2012, 09:50 PM
My Toro 51990A weedeater / brush cutter was/is giving me problems. It was a $180 trimmer from Home Depot (Canada) with a build date of 2006. I probably bought it in either 2006/07.

My weedtrimmer is leaking gas into the crankcase through the carbs (of course - where else?) It was in the shed for about a week after the 1st use of the seaon and went from 3/4 tank to about 1/4 tank without using it.) Worse fuel economy ever. When this happens, about 1 oz of gas will shoot out the exhaust when you pull the starter.

1. There are 3 sizes of sparkplug sockets. 5/8 and 13/16ths.... I was using the 13/16ths, but after getting the flooded plug out for the 5th time, I noticed it was loose in my socket... turns out its 3/4" size.

2. A really flooded (like wet spark plug) engine will not start, no matter how many blisters are on your pull hand from yanking on the starter handle

3. Kill switch just grounds the coil to stop the engine. On is open, off is closed.

4. Do not attempt to start a dead weed trimmer engine without the clutch cover on, or the kill switch attached, and it loose on your work bench. It will no doubt start, and it will be held by your starter cord as you try to keep it from bouncing around your garage floor, until the gas in the carb runs dry. (only about 30 seconds or so)

5. When you do #4, the clutch weights will expand outwards from centrifigal force, causing the clutch spring to over stretch.

6. When your clutch spring over stretches, it will not go back into shape by squishing the coils back with needlenose pliers.

7. If you squish the stretched springs with the needle nose pliers, held in place in your vise, and then heat them to a dull red colour with your propane torch, and then cooled with a wet rag it holds its shape.

8. The more times you take a Walbro WYC carb apart, the easier it gets. I still do not understand everything about this carb, but I am way ahead of 2 days ago.

9. My rubber diaphragms and gaskets from a 2006 engine look to still be in good shape (no tears) and seem flexible to me, but I can't get the engine to stop flooding. I have a rebuild kit coming.

10. Ebay has Walbro rebuild kits for about 50% cheaper than my local small engine place who would have to order them in. (under $12 with shipping (and probably no tax) vs $18 plus tax from the local shop.

11. My piston, ring and cylinder look good. Ring moves freely in the slot, no marks on piston or cylinder. (1st time taking apart a 2 cycle engine)

12. I spent 4-5hrs over this weekend working on this weed trimmer. If I was employed, it wouldn't be worth it, but I learned 11 things for free....

13. A local store has refurbed Ryobi units which should fit my attachments for $80 (curved shaft) and $120 4 stroke

Peter
(with weed trimmer that still floods)....

Shadowdog500
05-13-2012, 09:54 PM
When my TORO gas trimmer gave up the ghost last year, I wound up getting a $39 disposable Black & Decker electric to get me through the rest of the year while I researched what new gas trimmer to get. I was surprised that it was no big deal doing the perimeter of my yard with a 100' chord. Last week the B&D toy weed wacker died (as anticipated) and I did some research and bought the Stihl electric string trimmer for $119. it is big and beefy like a gas string trimmer its quality made in Austria, and people seem to keep them for years with no problem.

Chris

Hank McMauser
05-14-2012, 01:34 AM
I've got a stihl commercial model, don't recall the model #, but it has quite a bit of displacement,and is one torquey SOB. I've had it for about 4 years now(got it 2nd hand) and it has run fine since I've owned it. after using this beast, i'll never go back to a homeowner model.

Heavy Metal Doctor
05-14-2012, 07:09 AM
I've got a stihl commercial model, don't recall the model #, but it has quite a bit of displacement,and is one torquey SOB. I've had it for about 4 years now(got it 2nd hand) and it has run fine since I've owned it. after using this beast, i'll never go back to a homeowner model.

same here, 'cept I bought mine brand new --- I hate the homeowner crap they sell in the box stores. My Stihl trimmer got started for the first time since the middle of last summer on Saturday -- 3hrs, 3 tanks of gas and 2 1/2 spools of line in the trimmer head later and the "jungle" is cut back around my place for while.

Dewaynep
05-14-2012, 09:08 AM
That Walbro kit (K10-WYC) only lists for $7.60. Are things that much more expensve in Canada?

petee_c
05-14-2012, 10:32 AM
I only went to one small engine place in a small town close to where I live.... He said it would be about $18 and he would have to order it in.....

Peter

Scotto
05-14-2012, 11:05 AM
I feel your pain. This weekend I rebuilt the carb on my Craftsman string trimmer with a Walbro carb. Got the carb kit off Ebay (Genuine Walbro) for $8 shipped. It started once for a few seconds, but that's about it. I've never had spark problems, but now it won't even start on starter fluid. These things are such a pain to troubleshoot.

I also may have problems with the fuel bubble and the rubber valve under it. I'm only gonna put another $10 into it and if I don't get it working it's going in the trash. The amount of time you spend on these things just isn't worth it.

clarkebd
05-14-2012, 12:02 PM
We've got a cheap Ryobi gas trimmer for 12 YEARS now... had to replace the fuel line and bulb. It does leak fuel between a seal but I only put a little in to trim the yard and then leave it. $49 cost me originally and still going. They are easy to take apart and it came with an exploded parts diagram to order anything you need. I knew it's a cheap brand but it's easy to fix when needed.

petee_c
05-14-2012, 12:26 PM
i am contemplating getting a better quality one.... however, I have the tiller attachment for this Toro, and while we only use it once or twice a year, it's nice to have a working powerhead for it......

Hopefully my carb kit works out... or I'll go with just filling 1/4 tank with each use. 1/4 tank should last me to trim around the yard, Alternatively, I could put a fuel shut off, but we'll see.

P

Jim_No_Garage
05-14-2012, 02:23 PM
Alternatively, I could put a fuel shut off, but we'll see.

My Toro Lawn Tractor did the same thing. I put a fuel shutoff in place - finished! At some point I'll figure out the true problem - but for now it's running!

Jim

petee_c
05-28-2013, 09:38 PM
reviving my thread from a year ago....

Well, I've got a job, and a Stihl Kombi KM55R with the sweeper and a straight shaft trimmer.

I had tried the trimmer head from the Toro which fits, but the trimmer attachment is only 27" long, while the Stihl is 35"(?) You really notice the difference in length.

My Toro powerhead is still not working. I can get it running, but it floods easily. I have taken the carb apart and cleaned it in an ultrasonic cleaner with Shout/Water, and then just plain water. Blew it out with compressed air.

I know it's not worth fixing, but the stubborn part of me doesn't want to lose. I still have the cultivator attachment for it, and being able to use it for that would be a plus.

I think it's the Pump Body Assembly (Walbro part 5-2883-1) that is faulty. I believe this is the part that has a check valve in it? Looks like online it's about $20 - which in Canada means it $30. A new Carb (Toro part #308028001) looks to be about $50 online.... It's in the WYC series of Walbro carburetors.

Is there a better or cheaper Carb I can put on this to win the war so to speak?

Peter

getbent4x4
05-28-2013, 10:36 PM
I find the $70 lowes trimmers in the county trash bin all the time. Piston/ring and cylinder scored because they are made out of junk metal. A few of the trimmer still looked brand new, not even dusty.

Skin
05-28-2013, 11:17 PM
Toro doesn't make most (any?) of their gas trimmers. Seem to be essentially the same thing as what the big box stores slap their name on.

theoldwizard1
05-28-2013, 11:49 PM
I'm lazy and retired and too old for those kind of first hand, "learning experiences". (I already learned a few of them; I have a 3/4" spark plug socket.)

Watch Donyboy73's channel on YouTube (http://www.youtube.com/user/donyboy73/videos) for advice on small engine repair.

Passages on small engine carbs are much smaller and easier to clog these days. Filled with all of your new found knowledge, I'm sure you will be tackling other small engine issues. Here are some of the things I have learned.



Diaphragm carbs (what are used on most small 2 cycle engines) must have clean fuel (dump out whatever is in the tank and clean the tank with spray carb cleaner) and perfect fuel lines. If the fuel lines are the least bit hard/soft/suspect, replace them.
Disassemble and soak your carb and parts overnight in ChemDip (http://www.berrymanproducts.com/products/eco-friendly-products/berryman-chem-dip-carburetor-and-parts-cleaner/). A gallon bucket will last you a lifetime, if you remember to put the lid back on.


I am almost ready to go buy an ultrasonic cleaner.


P.S. You are correct. Practice makes perfect. I can pull a carb off of most B&S engines and have it stripped down in less than 10 minutes !

Bronson
05-29-2013, 12:04 AM
Bad crankshaft seal?

theoldwizard1
05-29-2013, 08:52 AM
Bad crankshaft seal?

Possible. Few people (including me) have the proper equipment to pressure/vacuum test a 2 stroke crankcase.

TAMPAGT07
05-29-2013, 08:56 AM
I bought a weedeater featherlite like 10 years ago...It still runs like a champ...Not bad for $70 at a Sears outlet store....

petee_c
05-29-2013, 09:23 AM
Bad crankshaft seal?

I hope not.

I ordered a carb from a local small engine place $52. In the grand scheme of things, probably not worth it. But I will not lose.

Peter

flyng_fool
05-29-2013, 09:29 AM
i am contemplating getting a better quality one.... however, I have the tiller attachment for this Toro, and while we only use it once or twice a year, it's nice to have a working powerhead for it......

Hopefully my carb kit works out... or I'll go with just filling 1/4 tank with each use. 1/4 tank should last me to trim around the yard, Alternatively, I could put a fuel shut off, but we'll see.

P
Many of the attachments are universal if you get one that has the capability of swapping out the bottom part.

Jagmandave
05-29-2013, 11:06 AM
I just went thru a similar situation with a friend and his chainsaw......the kit for his particular Walbro carb was $18 but by looking around a bit on the interwebz he found a new carb for $20. Put it on, fired it up, works perfectly. Job done.

Hope yours is successful too.

Victorymike18
05-29-2013, 01:32 PM
I've tinkered with small engines, with mild success, so I share some of your frustrations.

I wanted to add that I bought a low end 4-stroke string trimmer last summer when the cheap $89 Homelite 2-stroke would sputter and die more than it would ever run...

Buying a 4-stroke was what I should have done in the first place. It feels only slightly lower on power (if I use the tiller attachment) but is a lot quieter and I don't have to screw around with mixing the gas. It has not let me down yet.

Too_Many_Tools
05-29-2013, 01:42 PM
My Toro 51990A weedeater / brush cutter was/is giving me problems. It was a $180 trimmer from Home Depot (Canada) with a build date of 2006. I probably bought it in either 2006/07.

My weedtrimmer is leaking gas into the crankcase through the carbs (of course - where else?) It was in the shed for about a week after the 1st use of the seaon and went from 3/4 tank to about 1/4 tank without using it.) Worse fuel economy ever. When this happens, about 1 oz of gas will shoot out the exhaust when you pull the starter.

1. There are 3 sizes of sparkplug sockets. 5/8 and 13/16ths.... I was using the 13/16ths, but after getting the flooded plug out for the 5th time, I noticed it was loose in my socket... turns out its 3/4" size.

2. A really flooded (like wet spark plug) engine will not start, no matter how many blisters are on your pull hand from yanking on the starter handle

3. Kill switch just grounds the coil to stop the engine. On is open, off is closed.

4. Do not attempt to start a dead weed trimmer engine without the clutch cover on, or the kill switch attached, and it loose on your work bench. It will no doubt start, and it will be held by your starter cord as you try to keep it from bouncing around your garage floor, until the gas in the carb runs dry. (only about 30 seconds or so)

5. When you do #4, the clutch weights will expand outwards from centrifigal force, causing the clutch spring to over stretch.

6. When your clutch spring over stretches, it will not go back into shape by squishing the coils back with needlenose pliers.

7. If you squish the stretched springs with the needle nose pliers, held in place in your vise, and then heat them to a dull red colour with your propane torch, and then cooled with a wet rag it holds its shape.

8. The more times you take a Walbro WYC carb apart, the easier it gets. I still do not understand everything about this carb, but I am way ahead of 2 days ago.

9. My rubber diaphragms and gaskets from a 2006 engine look to still be in good shape (no tears) and seem flexible to me, but I can't get the engine to stop flooding. I have a rebuild kit coming.

10. Ebay has Walbro rebuild kits for about 50% cheaper than my local small engine place who would have to order them in. (under $12 with shipping (and probably no tax) vs $18 plus tax from the local shop.

11. My piston, ring and cylinder look good. Ring moves freely in the slot, no marks on piston or cylinder. (1st time taking apart a 2 cycle engine)

12. I spent 4-5hrs over this weekend working on this weed trimmer. If I was employed, it wouldn't be worth it, but I learned 11 things for free....

13. A local store has refurbed Ryobi units which should fit my attachments for $80 (curved shaft) and $120 4 stroke

Peter
(with weed trimmer that still floods)....

LOL...good post.

Education is never free.

Good luck with the effort.

Too_Many_Tools
05-29-2013, 01:50 PM
same here, 'cept I bought mine brand new --- I hate the homeowner crap they sell in the box stores. My Stihl trimmer got started for the first time since the middle of last summer on Saturday -- 3hrs, 3 tanks of gas and 2 1/2 spools of line in the trimmer head later and the "jungle" is cut back around my place for while.

LOL..FWIW...the Stihl trimmer I have (commercial model) is the most troublesome engine I have..always a major PITA to start but runs once it gets going.

Major Ramifications
05-29-2013, 02:08 PM
The Toro trimmer that you describe is a good little unit, despite being made in China. We sell that same unit as a reconditioned product under the Ryobi Commercial brand. They are $110 for the curved shaft and $130 for the straight.

You can get a new powerhead only from Home Depot for $120 and use your current attachments. http://www.homedepot.com/p/Toro-2-Cycle-25-4-cc-Power-Head-51945/202524827#.UaZRzH4o6Uk
FYI, the attachments also work on Ryobi and Homelite trimmers.

superspec
05-29-2013, 02:28 PM
stihl FS76 here and it is going on 17 years old. never been rebuilt other than the gas bubble and a new bump head. it runs all year long and it spins the big boy black line in the .130" diameter.

KJ4VYI
05-29-2013, 04:42 PM
The Toro trimmer that you describe is a good little unit, despite being made in China. We sell that same unit as a reconditioned product under the Ryobi Commercial brand. They are $110 for the curved shaft and $130 for the straight.

You can get a new powerhead only from Home Depot for $120 and use your current attachments. http://www.homedepot.com/p/Toro-2-Cycle-25-4-cc-Power-Head-51945/202524827#.UaZRzH4o6Uk
FYI, the attachments also work on Ryobi and Homelite trimmers.

hahahahahaha orig poster - i had the same issue with my toro -- fresh gas new lines new pump -- no go 2 hours of my life i will never get back !!-- old worn out ryobi my boss gave me cuz it had rotted out fuel lines and broken pump-- lookd at the card -- same as the toro -- few screws for the card ant pull off the throttle link pull off the muffler put on the ryobi muff replace fuel lines -- and damn does gass hurt on an open blister from yanking on the toro -- pump and crank ran all day!!! tilling and cutting i hate week wackers but at least it works

petee_c
06-05-2013, 01:51 PM
Well... $58 later (after tax)... I have a new carb.

Damn thing is still not running.
I can prime the sh*t out of it, and get it started after about 10 pulls. (new blister on hand - thx), and it will run at WOT, but as soon as I release the throttle, it dies, then I can't get it restarted.

I will check the muffler again, to make sure the Spark Arrestor isnt clogged - (I'm pretty sure it isn't. I kinda remember taking the propane torch to it.) I don't remember an actual removable screen.

At this point, I've looked at the engine diagram at toro. This is a 2005 manufacture date trimmer. There is no crankcase seal available as it's own part. The crankcase is sold as it's own assembly. ($$$)

Hee's the parts manual link.
https://lookup3.toro.com/classes/doGetPub/?pubid=30376

I may have lost the battle.

Peter

superspec
06-06-2013, 07:53 AM
maybe it doesnt have enough compression?

jabin
06-06-2013, 09:33 AM
Does it matter if what type of gas? My grandfather was OCD about fresh 93oct gas in all his small engines. I have problems with old 89oct gas.

I really can't image that gas would produce such consistent issues.

theoldwizard1
06-06-2013, 09:46 AM
Well... $58 later (after tax)... I have a new carb.

Damn thing is still not running.
I can prime the sh*t out of it, and get it started after about 10 pulls. (new blister on hand - thx), and it will run at WOT, but as soon as I release the throttle, it dies, then I can't get it restarted.

But it does start and it does not leak gas out of the carb, correct ?

I think the carb needs to be adjusted. If you aven't messed with the high and low speed screws on the old carb, turn them in gently counting the turns as you go, until the needle seats. Use this as your initial setting.

If you carb has adjusting screws like below, you might need a special tool. I have heard that the red electrical butt splice connectors will also work.


Watch this video, especially at about 1:40

HOW TO ADJUST The Carburetor on Weedeater XT260 Grass Trimmer (http://www.youtube.com/watch?v=ZQ-kFqGeyMU)

Scotto
06-06-2013, 11:16 AM
I find the $70 lowes trimmers in the county trash bin all the time. Piston/ring and cylinder scored because they are made out of junk metal. A few of the trimmer still looked brand new, not even dusty.

Scored probably because homeowners put in straight gasoline without adding the oil.

petee_c
06-08-2013, 10:34 PM
Last weekend I put the new carb on, and it still not running right.

Progress!

Last night, I was tinkering in the garage, and decided to take a look again at the weed trimmer, to see what I could see about the crankshaft seals. Note. I couldn't find the crankshaft seals in the parts diagram for a Toro 51990A (damn I've been doing so much research, I know the model number of this 7+ yr old trimmer!)

Anyways, I got the pull starter recoil off. No obvious signs of crankcase goo leaking out on that end. Took the muffler apart (I actually never got to the spark arrestor screen last year, but looking again at the diagrams, I realized it is on the exit side of the muffler, not on the 'intake' side of the muffler.) The SA is clear. no blockage.

I start taking a look at the 'drive side' of the crank and get the handle and shaft off. One of the bolts that holds the clutch weights in place has backed off almost completely, only held in probably by the drum side of the clutch.

I put a dab of blue locktite on it and tighten it to spec.

I'm thinking that there is too much drag on the engine when it's at idle because the clutch is engaging too early which is causing the engine to stall at low speeds.

Remember back to the OP? I started the engine once without the handle attached, and the centrifical force of running it for 10 seconds caused the clutch weights to overstretch the spring. I used heat from a propane torch to put the spring back as close to original size as I could, and it holds the clutch weights in at rest. I think the spring is now too weak, and is allowing the clutch to be engaged at low speeds, when proper operation would be for the clutch to be disengaged. I can stop the trimmer head by pressing it against the fence, and then the engine would likely stall.

Anyways, the trimmer now runs, but the trimmer head doesn't stop spinning on it's own at idle. I turned up the idle screw 1 turn, and I can get it to continue running at idle.

The spring is still likely over stretched a bit, because I can hear the clutch weight knocking a little bit in the handle at 'low' speeds.

I try to wear down the clutch a little bit, but holding the string head in place by pressing it up against the fence, and throttling up for about 10 seconds -- to burn off some of the clutch material. Didn't seem to make a difference.

I can start the trimmer cold on the choke on 1-2 pulls, and then hit the throttle to get enough gas in it to overcome the drag of the trimmer head. I was able to trim for about 10 minutes in the 'back 90' of our yard tonight, and still restart it even when the engine was hot. For the most part, I am getting good throttle response, which should be a sign that the jetting on the new carb is in the ballpark.

I'll see how it runs for the next couple weeks, and put my Stihl trimmer aside for now. If the engine still continues to run, maybe I'll splurge the $20 on a new clutch assembly to to see if my theory is right....

Things are looking up.... :)

Thanks to everyone for their input, and internet diagnoses

petee_c
06-09-2013, 07:47 AM
But it does start and it does not leak gas out of the carb, correct ?

I think the carb needs to be adjusted. If you aven't messed with the high and low speed screws on the old carb, turn them in gently counting the turns as you go, until the needle seats. Use this as your initial setting.

If you carb has adjusting screws like below, you might need a special tool. I have heard that the red electrical butt splice connectors will also work.



This machine uses a Walbro WYC carb.... no screws to adjust. It has a spring lever to adjust inside the carb.

Peter