Took mine to repair shop and the guy told me just throw it away and get a Stihl. But followed your instructions and had it running in about 2 hours (and 10 swears). Thanks!

4 stroke ... more torque sounds awesome no fuel mixing required

Awesome job. Will be attempting to overhaul mine next week. When parts come in. Been sitting for at least two years. Just got two other ones going really surprised me, and carburetor are cheap instead of buying another one. Thanks for sharing. Update: parts came in cleaned fuel tank, new lines, carburetor, oil change. Pumped the fuel bulb 6 times. On third pull started right up. Runs like a champ. Didn't have to adjust the carb. Glad I didnt throw it away like I wanted to.

1 year of great trimming and 5 years of torture. Bad carb mount. I bought an electric. No problems at all! Thanks for a good video

I own this model and the Xp model as well. I purchased these after a turd stole my older version out of my truck. The older version was I think tb425 it was a beast. I bought it used but looked like new. Cost me $5.25 at resale shop. Replaced fuel lines work like a champ 2 years straight before I had to replace the 1st diaphragm. All in all I owned it 10+ years. And never replaced any hard parts. After that track record I decided. To pull the trigger on the new ones. Was I in for a surprise purchased from home depot web site. $150+ each. Out of the box hard to start. Which in 3 months the factory fuel line in the tank disintegrated . Just after the 90 day warranty expired. The diaphragm hardened. Bought carb kits back in business so I thought. Than Mickey Mouse recoils started to crap out. So I bought the adapter that attaches to my drill. Bad move the tail shaft sheared of of one of them after using the drill start. Bought part to fix this and discontinued the use of the electric start feature. These recoils are a real nightmare the e clips fall off end the spring dogs will stay engaged. In the bowtie on the recoil side. No as this month the are both 2 years old since purchased. And neither one wants to start. So they have been exiled to the barn. Pulled out the old PP335 slapped in a diaphragm swop out the pruned shaft and away we go for now. No more TB 4cycles for me.

Have the exact model with the same problem. Can't believe I was happy to find your video. I had to replace a valve spring not but a year after I bought the machine. Other than that, it's been great. Yes, I would buy another 4 cycle. Just runs at such a lower RPM and sounds much more stout.

I took and replaced that Walbro WYLA carburator with a WYL. It removed a fuel line and since then the trimmer has been working like a champ.

One main problem I have with 4 stroke trimmers is that you can’t turn them sideways, so you can’t store them like how you store a two stroke, I also tend to prefer speed over torque when trimming

I just finished repairing the pull start on one for a friend. She had to take over the yard work because her husband has bad COPD. But when I tried to show her how to use it. it was just to heave for her. I am letting her use my electric Dewalt until I can sell hers. Personally, I would not buy one even if I didn't have a bad back. There just to heave. You do good work by the way!!!

Thanks for your candid explanation.

Great video! I use canned fuel in mine, never any problems.

yep i,d give it a good go and see how it performs in the yard and all cheers from Australia.

I had an MTD 4 cycle trimmer similar to this one (I don't remember which if the many MTD brands it was, maybe whatever was the house brand for True Value hardware stores in the late 90's. As I remember, it lasted 7-8 years and was OK, but I admit when I replaced it, I bought a 2-cycle 25cc MTD straight shaft with the end that allows attachments. I liked not having to use a 2 cycle mix, but as I get older, I appreciate less weight with these things, that a 2-cycle engine gives you. But for a younger person, if a good used 4-cycle trimmer pops up for sale, you might just like it.

Your videos are awsome Very helpful GBY

I had one of these, it was the biggest piece of junk I have ever had. It ran okay for a while, but it did not seem as powerful as a 2 stroke and it bogged down easily and stalled easily. After having it a couple months, the pull rope broke, come to find out this is a common issue... instead of taking time to fix it, I got the adapter for my drill, which was also a pain as it would stall or die on me, so I had to stop what I was doing, got to get the drill and start it that way. Needless to say that got old really quick. My friend also had one very similar and the same thing happened with the pull rope starter. It seems quite handy that this is such a common problem on the models with the extra piece to buy to start it "for convenience". I think her's is still hanging in her shed where it has been for the past 3 years. I got an Echo 2 stroke because I got tired of cheap MTD products that last 1 season or less, and the Echo is the best thing I have ever bought. (besides for my Homelite SX-135 bandit from 1995 that still runs as a beater)

Great video, thank you!

Yes -- had an earlier version of this trimmer and it was awesome. Trouble free with minimum maintenance.

hey man if i seen your video on the craftsmen 4 stroke why its bogging down is because the carb is gummed up with ethanol you want spray wd40 or seafoam to free it up mine had the same problem but i sprayed wd40 in it and it ran better than ever since then

I would need to know more information before answering Your question. 1 did You use conventional or full synthetic? 2 did you change the oil on a regular bases? Engine oil breakdown in a 4 cycle normally leads to catastrophic engine failure. I personally own a Wemars 4 cycle brush cutter and up to this point I've only had one issue and that was a broken fuel hose. I only use full synthetic Mobile One and I keep a close check on the oil level. I have hammered this cutter through everything imaginable and it hasn't failed me yet. I have noticed with the 4 cycle there is more heat build up as You say. I love the torque of a 4 cycle at lower rpm's over a 2 cycle and the quietness. I would really like to know why so many are breaking and mine hasn't yet? (knock on wood)....!! The Wemars that I own may go down tomorrow but as of now it's still as strong as it was new.

All my lawn tools are 4 cycle. Yes they are heavier but I do not need to worry about mixing oil in the gas. For me if my lawnmower was 2 cycle then all my tools would be 2 cycle. The need to have two different gas cans has always been a deal breaker for me.

I have both and with the four stroke they sell a strap that you put over your shoulder and you can barley fell the weight of the trimmer .

Helpful video. I just completed the same full service on a $10 yard sale TB635 EC that previously wouldn't start no matter what you tried, and can say that your video also applies to my model. I bought a replacement carb + kit and followed your steps plus some others: New carb + fuel lines (with filter), also cleaned and re-oiled air filter foam, changed engine oil SAE 30w, installed new trimmer line, fresh gas protected with Stabil Marine 360, etc. I find that this TB trimmer seems to run hot so far but I haven't used it yet for an extended period. I do prefer my Honda 35cc 4 stroke cutter/trimmer, which is very reliable. I have nothing against 2 strokes at all. Note: Folks may want to consider that some spark plugs that will show up in your replacement carb kits can be the incorrect thread meant for a different machine than yours, so don't force it in and ruin your motor case. And, when replacing a carb, it can take a while priming and pulling to get fuel into the cylinder to get ignition, so take your time. To prevent future fuel related troubles, I recommend using fuel stabilizer with all your smaller gas engines.

Thanks, great video

Nice fix.

Great video

Yes I would buy one. I hate having to mix oil and gas.

I'm on the fence. They seem to run good and sound cool. The extra weight isn't a deal breaker for me but I am not impressed with the quality of the Troybilt models.

Thanks for a good video

Very helpful!

I bought a pricey 4 stroke for the kids. Nothing but problems early on… my great value 2 cycle only needs minor adjustments to stay working for years ( they are both troy bilt

After fixing equipment, I would love to see you use them.

you ask about a 4c vs 2c well i have a different model troy bilt and i HATE it.((when cold))..new out of the box its a pain on a first start to keep running...no carb adjustment....still tho once warmed up like it a lot...i recently bought a ryobi and love it!! yes like you say they are a little heavier but man do they work...and i use a shoulder strap to help with holding it so yes for me i have a LOT of weed eating to do weekly not having the hassle of using mixed gas is a plus...4c all the way

4 stroke engines are lots of work, 2 cycle are much quicker but i think they get wore out just a little bit quicker. I just bought the new Egopowerplus string trimmer with the carbon fiber shaft, and a auto self wind feature. Let me tell you man, you gotta watch a. Video and check it out on their website, its really power beyond belief.i will be testing it out tomorrow on some of my lawns.

What's the 3rd fuel line for? Thanks good video quick to get to the point.

4 Stroke much quieter than 2 stroke don’t mind either, have a Honda UMS435 Brushcutter besides my Stihl 2 Stroke. Warning ⚠️ when storing 4 Stroke Brushcutters do so Flat, horizontally, not vertically upright, Oil will fill in exhaust and you may not be able to start.

Yes,I would prefer to buy a 4 cycle line trimmer over a 2 stroke one. My compression tester kit comes with the adapter kit to test those smaller engines !

Thanks,very good video. I ordered the same replacment kit and I was able to follow along & change out the parts without issue. BUT, I do have a question. Troy Bilt has a sticker that says push the primer bulb 10X . When I push this primer bulb, gas does fill the primer bulb but only about a 1/4 of the bulb AND with continued pushing the fuel gets dumped back out of the bulb, I assume into the gas tank?? Here's the crazier part, I am able start it & it runs with the primer bulb only a scant of gas in it. Just enough fuel to wet the floor of the bulb when its running. Most of the time primer bulbs fill up and your done pushing it. IS THIS NORMAL OPERATION FOR A PRIMER BULB??!!!!

If grass gets out of hand you want the four stroke trimmer. If using the strap, it's too heavy for you? Work at it in several tries or hire a young person. You can also get a used DR trimmer mower for less than a hundred if you do some searching. They do an amazing job and get the new style multi line head to use thicker lines and use multiple.

I think 2 cycle will last longer so long as you don't forget to mix 2 cycle oil. Much simpler design, less parts to go wrong. No oil to change. Most home owners will never check oil level and never change oil. I haven't seen a single person who changes oil in their lawn mower. Many don't even know it has oil. But then, I have seen 2 people destroyed 2 cycle engine by running it on straight gasoline, so maybe 4 cycle will last longer for those kind of people.

I have done probably 100 of those for warranty reasons and I have seen about half of those exact models catch fire that were horrible units

Awesome, I just got the same one and the diaphragm looks bad got it ordered you couldn't find just a diaphragms or replacing the carburetor then I'll see if it runs thank you

The 4 stoke easier to start hot or cold especially as the engine ages.. weight isn't that much of a factor considering people are gravitating to battery cordless which is way heavier especially when paired with a big battery to get decent run time.. 2 stokes are more finicky

I just bought a used 4 stroke trimmer even though I already had 2 stroke trimmer. Because its 4 stroke. 😁

Might wanna slightly adjust the mixture as when you applied the gas to maxx it choked a bit, just a tiny turn on the screw I'm sure would fix it..FYI

Mine blew the piston and rings and I can’t find a short engine block anywhere.It’s a TB525CS

I know you can do it on a trailer when it rains but, after you use a weed eater, blower, edger, etc. and you put it in the shed when it’s empty, can you use a plastic bag to cover the engine while it’s inside the shed?

i have the same trimmer , its awesome , however im looking for a 3 port primer ball . any info is appreciated

Have one just like this. It quit running because the in tank fuel lines actually deteriorated. No I didn’t use ethanol gas. New fuel lines and it runs good again. Don’t really care for it. Kind of heavy and clunky. Not really easy to start either, but it works ok. Good video.

I did all that but I don't get any fuel on the top where the bubble is. Any help. Thank

Did you ever put the new primer bulb in, and reattach the 3rd line?

If I have that EXACT SAME trimmer and it will NOT prime. Is replacing the carburetor the best option??? When I poured gasoline in the spark plug it fired up VERY EASILY! I’m at a lost atm! Lol

I got this trimmer for 70.00, the exact same one except it is a craftsman which is the exact same company. I got it for 70 because it was a return item and marked 50% off even though it as brand spanking new. LOL no joke. it;s even the same color. If you dont want to have carb problems ever, use clean non ethanol fuel.

Mine will not run at high speed. I have adjusted the valves to .004 and checked the spark arrestor screen. It was not dirty. Blew through muffler so it’s not that. WTF this is driving me crazy. New carb, new 3 port primer bulb. All fuel lines connected properly. It will not take off and rum on high.

Could you show me how to change weedeater line on this particular model, I have one and not sure if im doing it right

Does it have an automatic sensor if the oil gets too low

I received a Troy-Bilt TB525es 4-Cycle Gas Trimmer from Father-in-Law family upon his passing and It's in excellent condition. I would like to ask if there is a substitute oil I can use for this Trimmer's motor as the Operation's Manual states on page 4 under the title RECOMMEDED OIL TYPE "Failure to use the correct oil... can cause premature engine wear and failure. Use a high-quality SAE 30 weight oil of API (American Petroleum Institute) service class SF, SG, SH" I am unable to locate any oil with the API service class of SF, SG, or SH. Thank you for any help anyone may be able to provide.

I have one only about one year old used it one time never worked again. Filled with non ethanol gas. Think it’s an electrical problem no time to sort it out

I have the same model and it leaks gas from the gas tank when I tip it backwards and I can’t figure out what’s causing it. It’s definitely coming somewhere between the tank and cap.

Did it Started right up Runs sluggish But is leaking gas from carburetor Checked all fuel lines What's happening here?

What’s the link for the kit you got? It looks like everything I need. I have a TB625EC

What indicates that a user may "overfill the engine"? Since it doesn't have a dipstick, how can one determine if it's enough pouring out a quart container? Is there any physical signs that it's over or underfilled?

Good for light homeowner use only. These trimmers are made to run 75-100 hrs before problems start happening. About 4-5 years of use.

I have a 4cycle TroyBuilt trimmer. I picked it up second hand. When started it would not get to full power (would not get a blower going). I replaced the carb with a new one and it still does the same thing. Since there are no high or low on the carb do you have any idea how to adjust it so t will get to full power?

What kind of oil does it need?

Can you please tell us what the compression should be?

I had one of these for a couple of years and the recoil broke constantly over and over I swore to never buy another one. Junk cheap made I switched to stihl and echo pays for it self when you think about it for tears and years of trouble free service

Where did you buy this carb kit?

This was a good video. My only thing is would it have been just as simple to replace the rubber bulb on the original primer bulb and used the plastic portion from the original for all 3 lines to be used!? personally I would not like to use or own a 4 cycle, they are more expensive and heavier. Moreover I think the 2 cycles are much better and if you buy the right fuel you can get it pre-mixed ethanol free and not have to worry about mixing or adding oil. Good job on this fix. Oh also another note I got a similar thing when I bought a new carb kit for my Troybuilt trimmer, it came with many things like you got... lol

Hello there! I'm working on tb685ec 4 cycle engine. Starts and runs for about 3 minutes and then shots off. Starts right up after it dies. I put a new carb in it, adjusted valves, and still doing it. Any clue what it might be????

Where can I find that electric starter gadget at??

How many cc is that trimmer

Mine only idles.now new carb and fuel line filter? Doesn't run

mine starts with the electric start but not with the pull rope... any ideas?

While my specimen might have cheated death (SOMEHOW it still runs), I'm not going through the trouble of getting replacement parts. The poor thing is TRASHED. Missing parts and the recoil does NOT inspire confidence. It's just not worth it.

I have one

Set valves a .004

Only if Stihl made a 4-cycle trimmer, maybe. Otherwise I don't mind having to mix gas and oil.

I use my trimmer to edge, so unless it was left lighter and had a split shaft, I wouldn’t be interested at all. Besides, there’s just something about the way a 2 stroke sounds…

My troy-bilt tb35ec has 9 psi

Yes, 4-cycle trimmers are better if the oil is changed often. Go electric if you want everything easy.

The power switch went bad on my electric starter and had to replace that, but it is an awesome trimmer! Love mine.

I have had this sam trimmer for years and it is a big piece of junk! However, like a clueless hack I keep repairing it.

👏👏👏you have lucky in your goofy 🥴 job s

2-stroke for sure

2 stroke for me I think there more reliable and sound better.

Nope ill stick with 2 cycle.

I'd pay more for a battery powered trimmer

These things are junk. The pull start mechanism breaks and has no parts available. Beware

Yes to 4 cycle