Fix for bogging and low power with Honda GX25 & GX35 engines.

If you have been having an issue with your little 4-stroke Honda engine bogging or stalling out, especially at wide-open throttle, this may be a fix for it.

[@AshMcSplash]

Thank you SO much for this video. I've had a UMK25E grass cutter with this engine on and it bogged down on full throttle from new, but I unfortunately wasn't in a position to exchange it at the time and had to make do! Everytime I've used it I've limited myself to pulling the trigger half to 3/4's as you mentioned, any more than that it stalled. Its been in storage the last year and pulled it out yesterday to see if it was still doing it. I troubleshooted all afternoon and even noticed the kink in pipe, but didn't think that would cause it! Stumbled on your video today, cut half an inch off the pipe and it runs at full throttle!!!!! Wish I'd found this video 3 years ago! Thanks!!!

[@CanadianDirt]

Thanks for reaching out, glad it helped.

[@dougwachs]

This is the wonder of KZbin! One person figures something out and shares it with the world - I've had the same problem with a mantis tiller and a honda trimmer. You are my personal hero for the day! Thanks for figuring it out and sharing the solution!

[@Fabs_32]

You sir, are a life saver! Thanks for making this video. I didn't even think of the fuel line being the cause. I was leaning more towards a carby issue. But this was it. I cut that plastic sleeve off which had gone hard and also noticed it was squished where it goes into the tank, the rubber around it had compressed it also. Mine is about 5 years old.

[@jamesmoyer1690]

Totally awesome solution and presentation. My 4-stoke Mantis tiller was bogging down at full throttle after it warmed up, and I was totally perplexed. Thanks for the great tip!

[@1Longranger]

Another problem can be a little rubber non-return valve in the fuel cap which can lead to sudden stopping after 10 minutes or so of operation. Also, the fuel line can sometimes double back in the tank, kinking it.

[@keithnoneya]

Best Unit I've owned over the last 6 years. It does require some rocker to valve adjustment every few years but this little thing is a beast when it comes to trimming. It trims well even tall grass without having to clear the head every two seconds. I'll never go back to Craftsman, Echo, or any of those other brands, I've owned them all. It's the Best $300.00 weed whacker ever. Best Wishes & Blessings. Keith Noneya

[@gpetheri]

Mate you pointed me in the absolute right direction to fix my whipper snipper that conked out at full throttle. With mine, there's a plastic clip that pulls the two hoses away from the bulb and holds them against the main motor body. This stupid design kinked the fuel hose almost shut. I snapped off the clip, fitted a new fuel hose (better material), and shortened the return line too. But..... it still wouldn't run. Turns out the fuel hose inside the tank to the filter is such soft garbage material that as soon as the engine draws fuel, the hose just collapses. I fitted new hose there too and now it runs perfectly. Thanks Champ.

[@CanadianDirt]

Thanks Glen.

[@R210288]

Thanks too for this video, you brought me back to basics - on a relatively new engine, if it idles OK there are really only two things that can limit normal power output and that is (a) fuel constriction or (b) air constriction. That fuel feed line was kinked on my GX25, so I replaced it with some slightly bigger id clear tubing and it works great!😃

[@meteora8888]

Where did you get the new fuel line and what is the size? Thx

[@fyc621]

I had the same problem and remedied it by using a steel spring as a sleeve for the fuel line.

[@muddy250]

Brilliant spot. Just trimmed my brushcutter line and for the first time the damn thing will run at full throttle no problem!

[@CanadianDirt]

Thanks for taking the time to comment about another successful fix.

[@desmo8755]

I made the mistake of overpaying for a Honda GX25 in a Honda-branded trimmer. Has not run well since about the second season. Might run one time out, then the next will run for 10 minutes and then die under power and hard to restart then and after cooling off. Intermittent, but mostly won't run. Have gone through the entire carb, checked for air leaks and debris, tried using only expensive canned gas. New plug, fuel lines, gaskets, fuel and air filters, checked the exhaust screen, gas cap venting, and anything else that could be a culprit. The fuel hose is not kinked. Ignition is fine. Doesn't seem to be vapor lock because sometimes it won't run well cold. Have never had a small engine problem I can't get to the bottom off, until this. I think I did finally find the cause, though ... these engines, or perhaps the fuel system but therefore let's call it the engine assembly, are unreliable junk. When you tear into one of these, you realize just what they are ... glorified, under-designed $75 machine. Trying new carb, in case there's a defect I can't see, and if that doesn't work the whole $450 unit is going in the trash.

[@CanadianDirt]

Goodness, that is frustrating. This really sounds to me like an intermittent air leak. Sometimes the way a plastic cased tool is held or leveraged on, it can stress a point that allows air in after the carb. I would be using carb cleaner or brake clean to look for a hard to spot air leak. The reality is, EPA constraints on these little engines have made tuning them finicky.

[@desmo8755]

@@CanadianDirt Thanks for the reply and I think you're correct. One of the more recent things I tried is spraying starting fluid at the carb body near the base. The idle drops and the engine will even stall. So I changed the gasket between carb and plenum (even tried Hylomar before new gasket arrived), and the gasket at plunger bulb. No change. If there's a leak, I can't locate it. Even took the plastic plenum off (between carb and engine) to change the o-ring in the intake port. Maybe there's a colored die propellant I can spray and check the leak path? Also seems like a lot of air in the prime / plunger line (return side), but some of that might be normal?

[@CanadianDirt]

@@desmo8755 A little air in the primer bulb is fine. Foaming in the primer bulb / fuel line is not and indicates an air leak in the line or hose fitting. Doing a vacuum test on the engine could help confirm an air leak, but if you were able to stall it out with the starting fluid and are sure that you were not getting any in the intake, I probably wouldn’t bother with the vacuum test and would go straight to using low pressure test and soap in a spray bottle.

[@devinbreeding5412]

I’ll take it if you just so happen to be close to The South Carolina coast…. I’ve had great luck with three of these engines fortunately.

[@devinbreeding5412]

@@j.777hemi2 I thought I’d follow up with an additional comment. 1 of my 3 bogged down at full throttle and I discovered it was a gummed up fuel cap. Easy way to tell. Idle the engine, unscrew cap to release pressure then reinstall and see if it runs strong for a minute before the tank repressurizes. Mine would run for about 5 minutes after releasing pressure, then start bogging again. Replacing fuel cap should solve in that case.

[@bigboybuilder77]

Thank you very much. My weedeater was bogging down too. That was exact issue with my gx25. I wanted to avoid paying 80 bucks to have it serviced. Even thought about replacing carb myself. Finally came across your video. There was a kink in that hose. Removed the sheathing and flipped the hose upside down. Moves hose enough out of the way to access primer bulb and trimmed half inch off the length. Thank you again she runs beautifully again. Yess sir!

[@BumBee22]

Thank you very much. I removed the fuel line sleeve and cut off enough off the fuel line to reach both connection points. I don't use the primer, I use the choke when first starting this trimmer.

[@davemcfadyen7629]

Just checked out my 5 year old Honda mini tiller and noticed the same problem!! I’ve rebuilt the carb and never noticed.

[@davidt1788]

Thanks for this! You totally saved me a trip to the mechanic!

[@JeffBond-l6l]

Having this exact problem and I will try this fix. Thank you!

[@lmgp1941]

Thanks I did it but also I suggest for people like me be advised to replace the fuel hose in a yearly basis whether is used or not to keep it vith out Cracks

[@RussellBooth1977]

Another problem to check is for a partially seized clutch drum, gearbox or the driveshaft as well. I have just received a Chonda GX35 engine today which I am replacing the 22 year old original & had it engine with because it was burning oil due to a scored cylinder, anyhow,I ran the new engine just as an engine without the brush cutter attachment bolted onto it & it kept bogging down at full throttle. Now,I saw rub marks on the new clutch shoes so I am going to run it with the brush cutter attachment tonight before even contemplating touching the carburettor. I think that it's because the clutch shoes are touching the outer housing that it's overloading the engine,it would be the same deal if the clutch drum, driveshaft or the gearbox was partially seized !

[@RaviSingh-zm1oc]

My issue on bogging was the feed line in the tank. This line is supposed to pick up fuel from the lower parts of the tank. This line had deteriorated and was sucking air when the carb was at high throttle. I replaced this tube and the bogging resolved.

[@kentonanderson9409]

thanks from Minnesota. cleared up my issue!!

[@seahippies]

Same on the SX50...thanks from Ausrtralia

[@peterorro883]

I have one of these. Well spotted...thanks for the heads up!

[@davidlewis7382]

excellent video solved my problem

[@williammeszaros3382]

Thanks for that! What's the best way to clean the Honda engine? I've heard of using brake cleaner, but I'm not sure.....

[@CanadianDirt]

I often just use a steam cleaner (high pressure steam) on small engines, but brake clean will work fine. Be careful with some cleaners like Castrol Superclean as it doesn’t play nice with aluminum. Spray Nine is an excellent degreaser that is a little more aluminum friendly.

[@jeremymassimino1176]

Hello, are you still answering questions? Thanks for video, my current issue is after a few seasons, it won’t hold an idle anymore. What is the first thing to try?

[@CanadianDirt]

First thing is to clean or replace the air filter and spark plug. Next would be to clean the carb and if needed bump up the idle a hair.

[@jeremymassimino1176]

You Rock!!!! Thank you

[@markrosinski4814]

Hi Could you help me to locate idle screw on gx25 please @@CanadianDirt

[@CanadianDirt]

@@markrosinski4814 on the carb body, looking at the pink or clear fuel return line, go up about 1” and you’ll see two screws. The left hand one will be the idle set screw

[@mickwolf1077]

Mine has been dying even randomly at times, I push primer and bulb doesn't recover as like it can't suck fuel. It has a few hours and I'm assuming filter isn't blocked because it eventually works again. So I'll be checking the pipe tomorrow, the thing only has a few hours. Thanks for the tip

[@CanadianDirt]

I hope it helps. Your thumbnail looks like a friend of a gold panner I know (Chris B.) Wouldn’t happen to be the same Mick Wolf would it?

[@mickwolf1077]

@@CanadianDirt nah not me, I'd like to get into panning around here, lots of Goldfields in the hills close by.

[@mickwolf1077]

@@CanadianDirt the pipe wasn't the problem 😔 mine appears to be a revised model, I think its in the carby somewhere. Fuel (air by blowing) can go in when the diaphragm is pushed but not normally. I'm thinking they weren't clean when putting it together at the factory as it looks a bit dirty inside 🤷‍♂️

[@CanadianDirt]

@@mickwolf1077 Check that the gas pickup is not hanging up inside the tank. Honda uses too large of a pickup filter for the size of the tank.

[@mickwolf1077]

@@CanadianDirt fuel was coming through the pipe freely but while the carb was apart i took out the needle valve and cleaned it then put it back together and then fuel flowed through the primer again, it started first go and has full power again ☺ It must have been the needle being dirty and not letting anything in when operating its normal range. Hopefully it doest happen again as I need it for work.

[@walterskinner527]

I bought a GX35 and it has an issue when I'm using it' it will run ok for aprox 15 to 20 mins and stop, I have retuned the motor to the supplier and they say it was dust in the flywheel. When they returned the motor I used it for 20 mins and it still done the same thing and it is difficult to start again. I will look at that fuel line and see if it is the same. Thanks for uploading the video.

[@CanadianDirt]

Hi Walter, another issue that sometimes happens with small engines like these which have complex gas tanks is that the gas pickup inside the tank, which is meant to be able to flop around and always end up at the lowest point where the fuel is, irregardless of the motors orientation. Well, sometimes it will get stuck in a higher position and as such the engine will only run on a full tank of fuel. I’ve had to get in there with a thin pair of needle nose and untangle the pickup hose.

[@walterskinner527]

@@CanadianDirt Hi, thank your your reply, I had already looked at the fuel pickup, in this case I had filled the tank thinking I was going to do a few hours work however I will see what I can do with regard to to pickup, Cheers thank you.

[@Booki89]

I just bought a brand new Honda blower, HBB25 and irs bogging out same as you describe. I can't see any fuel line kinks though...

[@CanadianDirt]

The kink might only be evident at full throttle when the suction from the carb is collapsing the hose.

[@raulrivera94]

Great video thanks a ton!

[@K162d]

hello, I saw your video and it actually was slightly kinked. Thanks! But there's a twist, the machine still stalls out and then proceeded to cut off... any tips or tricks?

[@CanadianDirt]

Check to see if the pickup tube and filter are freely moving in the gas tank or if they are stuck in a higher position. Does that make sense?

[@markpinther9296]

I will look at this. Mine is on an ice auger... very new. I believe my bogging is caused by my gas cap not venting properly OR me overfilling the fuel tank and causing my own venting issue with too much fuel. As soon as I open the tank cap, I can drill a hole or two. Annoying.

[@CanadianDirt]

Tank venting is always a good idea to check.

[@Jazril]

i have an european version of this, same engine, called the umk 435. the kink is even bigger since they placed the tube behind some sort of clip. not quite the same as your issue, but the root of the problem was exactly that same piece of tube. thank you very much! Edit - Can you please tell me the diameter of the tube in milimeters?

[@CanadianDirt]

I think it’s 3mm line.

[@tstabno]

Great video! I had this problem with a GX35. The engine is on an ice auger. I would drill two holes and it would stall. Much better performance after shortening the fuel line as described in the video. My engine is about 5 years old with light to moderate use. Do I need to clean my carb? Will a carb cleaner such as Seafoam clean the carb? I still bog a little bit and it will kill if I drill 5 ice holes in a short amount of time.

[@CanadianDirt]

Hi Todd, I’m hesitant regarding the use of sea foam in 2 strokes, just for concerns about reduced lubrication. It might be perfectly safe, I just can’t say one way or the other. The first thing I would check on your ice auger is where is the location of the pickup tube in the gas tank when your auger is in the working position. The pickup tube and filter on these little engines doesn’t change positions very well and due to the strange gas tank shape, the pickup can get lodged in a position that leaves it sucking in some air when the PTO / output of the motor is pointing downwards.

[@marknye51.thefixitguy]

I replaced the hoses and made sure they weren't kinked and it's still bogging down on full throttle

[@Booki89]

You ever fix it?

[@CanadianDirt]

Next to check is that the fuel filter in the tank is clean and not lodged somewhere high in the tank where it’s sucking air. Then also check the spark arrester screen if your unit has one.

[@roryrathbone]

Absolute legend

[@CanadianDirt]

Thanks!

[@Billster1955]

Thanks

[@mlaopiuayhszalaoiusyh]

Lewis Sandra Hernandez Daniel Lee Kenneth

[@AussieDazza]

Good video, I just wonder why so many Americans mispronounce Husqvarna. They say it like Husq - a- varna ?

[@Shirley-hr8tx]

Good to know,thanks

[@jaydanhazelton3190]

I did this to my gx25 and it had no effect on it at all also tried taking out the spark arrestor mesh in the muffler and still no fix... What could it be??

[@Olemil69]

You my friend are the answer to my prayers!! I bought a brand-new Honda HHT25SLTAT last summer since I have been a true Honda fan for decades, no matter what it is. Well, I had the same problem right out of the box, minus the stalling. It would run fine up to half throttle or a hair more, beyond that it would start to stumble, miss and lose power. Well like others commented thought it just needed to break in, nope. So glad I found this video, I just trimmed 1/2" or less off the line and it runs like a Honda now!! I tried it in the yard cutting almost to the dirt and didn't even begin to stumble. Thanks again for this great tip, I am a little disappointed they would engineer the hose in such a way. Maybe use a formed hose or even put a spring on the inside to keep it from kinking. Thank you and keep up the great work!!

[@CanadianDirt]

Thanks for the feedback. I agree, there’s multiple ways they could have prevented this issue with a little more thought and time spent in R&D.

[@scottmckee5316]

thank you for this fix. i am by no means a mechanic. this engine is on my ice auger and i have had it into the shop twice, both times i was told all fixed and working well. NOPE. watched this video last night and did the alterations tonight when i got home from work. AWESOME!!!!!!!. THANKS AGAIN...

[@walterskinner527]

I looked at my Honda fuel supply and it doesn't have that rubber piece. my Honda GX35 runs for aprox 15 to 20 mins and stop, have you any idea what els should I look for, I have only had it for few months and had the problem since new.

[@CanadianDirt]

Hi Walter, I replied to your other post in the comments here.

[@atomikrobot300099]

This just happened to my 2 year old GX25!

[@wingnutbert9685]

Thanks for this Eh. Just about to buy one. I'll check the tube and clip if needed right outta the box. ???= What kind of gas is best to run in these? Premium? TruFuel? I just got a water separator filter after discovering the inside of my 2200i gen fuel cap was rusty. Thanks for this video!

[@CanadianDirt]

I prefer premium (91 octane) with no ethanol in it.

[@winter4uandme]

Good video. I have that exact issue with my Honda GX25 engine. Can’t wait to see if your solution fixes my problem. Thanks

[@alexhogan1]

Mine doesn’t have a sleeve it is folded behind a small plastic clip and still has this problem

[@CanadianDirt]

You may want to try replacing the fuel pickup hose with a new transparent (and stiffer) hose.

[@ARTComputerRepair]

Thanks, i think this may the the issue I'm having! ill have to check it in the morning!

[@Darklightbulb]

I bought a Honda UMK425E. Same issue. Followed this video but still bogging out. Wonder if its a fuel filter or carb jets. First summer it worked beautifully. This summer it's bad. Not what you expect from Honda machines after just a few hours use. Any advice would be much appreciated. Thanks for the vid.

[@briana325]

Great video. I tried this fix on my gx25 but still had problems. Turned out the spark plug was falling out, the carburetor was loose, and the resonator needed cleaning. There definitely was a severe kink in my fuel line that was hampering performance. My husqvarna weed eater runs like new again, even though it’s 6 years old.

[@CanadianDirt]

Hey Brian, glad to hear you got all the bugs worked out of it! They’re tough machines.

[@jamestreanor182]

Awesome, fixed my problem 🎉

[@stitchjones7134]

Thanks for solving my whipper snipper issue!

[@carltonjones947]

Thank you sir! It worked on my GX25 string trimmer.

[@tjmooney4181]

Awesome thanks so.much i was getting so frustrated using at 1/2 throttle lol

[@honewaatamokepumipi8135]

shot brother , looking everywhere

[@MrCroissantBucher]

Doode, cool insight. Thanks!

[@hufy11]

I have a replacement carb. when I prime the ball, ]i can't get it to pull fuel thru the carb and return fuel. I don't think the ball leaks, what would stop the fuel to circulate

[@CanadianDirt]

First thing I would check is the condition of the fuel pickup line and the pickup filter.

[@theborglord]

Can’t wait to see if this is my issue

[@TeronYazzie]

Thank you for much!!!! My graco field paint sprayer - honda gx35 is not bogging down no more. I straighten out the line and ran the engine at full throttle. No low power or did it boggle the engine down. I now have a back up in case my field paint spayer I am using goes down.

[@CanadianDirt]

Great to hear! Thanks for letting me know it helped.

[@Kim_Miller]

Thanks for this tip. I checked mine and both fuel and return tubes sit behind a clip on the motor. The black one had the sleeve and the sleeve had hardened and forced the kink tight. I had to cut the sleeve off as it was also glued underneath. My tube seems to be made with a double wall, the inside layer is harder plastic and it didn't want to expand and go onto the spigot again. It took some pushing with pliers. Then it wouldn't prime and I could hear it sucking air. Unfortunately, when pushing it I punctured the tube. So, tomorrow I'll chase up some new tubing. The only time this motor has caused me problems was a year or so ago when it would run OK if I held it with the filler cap tilted down. if I rotated it clockwise in use it stopped. I figured it was the fuel supply tube not picking up fuel. Sure enough, inside the tank the tube had perished. A new tube fixed it. The thing was then only 2 or 3 years old. I'm not really impressed with these silly faults. My mower is an old Rover with a Suzuki 2 stroke motor. I bought it when my son was 15, he's now 41 and the mower is still running strong. Here in Australia Honda has a pretty good reputation but mine is not living up to it.

[@CanadianDirt]

I agree, here in Canada Honda is also well respected, which is why I’m surprised that they keep trying different small fixes instead of redesigning the carb and fuel pickup. The double wall tube with a glued sleeve is a new one for me, and it is now the 4th variation I have heard of Honda trying to fix this issue without incurring the costs of a redesign.

[@Kim_Miller]

@@CanadianDirt my neighbor is a lawn care guy and i asked if he had tubing. He said he had a graveyard of whipper snippers in the shed and he gave me a replacement from an old motor. It's green rubber that won't kink and fits perfectly. Don't know what brand motor but a lot better than the honda one.

[@JacobMelancon]

I have adjusted this and cleaned the carb but under load with full throttle the unit is killing. Any idea on fix? maybe fuel filter dirty?

[@CanadianDirt]

Next to check is that the fuel filter in the tank is clean and not lodged somewhere high in the tank where it’s sucking air. Then also check the spark arrester screen if your unit has one.

[@DM1977_]

Thanks mate it worked,had this problem with mine went and done this after watching it..😀

[@CanadianDirt]

1977 DM Great to hear! Thanks for the feedback.

[@Farang_Lifestyles]

fantastic info,,, thanks so much,,,

[@CanadianDirt]

Thanks Andrew.

[@CarlMadsen]

WOW! Thanks. That's so obvious, and such an easy fix. I really appreciate it. Mine was kinked half shut.

[@jackkobus300]

Thank you !!! after two years of putting up with half assed performance , your trick fixed it 100% Ha have a great day !!

[@andysmith3518]

When you say bogging down can i ask what you mean?

[@Darklightbulb]

It means as you increase the throttle the power fades out and eventually cuts out.

[@machaf]

Thanks for this. I've been dealing with this for 7 years. Going to go take a look.

[@MadTuning01]

I got a gx50 and it bogs down and dies when I hit full throttle but the fuel line seems fine could it be anything else ?

[@glennhawkins7915]

Thank you for taking the time to share this issue unlinked the fuel line and away she went👍

[@davidhallett7826]

Great tip thanks worked very well.

[@CanadianDirt]

Glad to hear, thanks for the feedback.

[@shanetbird1]

Good pick up sorry for the punn

[@wurzelle1999]

Great tip!

[@AussieDazza]

It is pronounced Husqvarna, not Husk-a- varna