Leaf Blower help.

DuckyDave

Six Pointer
At risk of starting WW3 about which Brands are best (I favor Stihl, Echo 2nd, Husqvarna 3rd) i was given a Husqvarna 125BVX handheld blower that defies almost every fix I can think of. Failure symptom is it runs for 30-60 seconds after priming via bulb, then it quits unless i periodically pump the bulb--all this while on either half or full choke. I have installed all new fuel lines, bulb, filter, carb and tested with fuel tank cap off/open. Fuel lines are transparent type so i can see fuel is not flowing to the carb. I have adjusted coil to flywheel gap so it gets a strong spark. I don't have a compression tester, auto store i usually borrow from isn't loaning due to Chinese Virus. I strongly suspect the Crankcase Seals are bad, especially the one opposite from Recoil Starter side (see photo). Cylinder walls are not scored, but piston shows some blowby. I figure as long as i am ordering new Seals for another $22-25 i will replace cylinder and piston and rings. Should be less than $50 to fix this blower which was given to me for free. A couple questions: 1) does the blowby/carbon on side of piston look normal? Unfortunately I have no idea how many hours this blower was used. 2) i have used arboristsite.com forum in past with some success, although replies have been slow/limited. Anybody know a better site? 3) do you think i am on the right track replacing Crankshaft Seals (as well as piston and rings and cylinder)? Gonna have a practically new machine! Thanks in advance for any input.
 

DuckyDave

Six Pointer
File Type .heic that my new cellphone camera uses is not recognized on this forum website. there is probably a way to convert .heic to .jpg but that is yet another project...

Anyhow I took a couple pictures after disassembly to show the piston carbonization/blowby and the Crankshaft Seal leakage. the leakage photos were more impressive before disassembly but unfortunately all thos photos were taken with my new cellphone therefore .heic FileType.

Here are some photos I took with an older camera (after disassembly) and Jpg filetype. The 2nd and 4th picture are the Seal opposite the Starter side and Orange Cover on that same side. This does not look normal/" healthy", right?
 

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Ol Copper

Twelve Pointer
Air leak in the carb somewhere.

Here at the shop my man wont fool with one any longer than you have. Just order a new one. Might not be the best option in your case but a new carb is cheaper than our hourly labor rate.
 

DuckyDave

Six Pointer
Thanks guys, sorry I wasn't clear but replacing the carb was one of the first things I did:

"I have installed all new fuel lines, bulb, filter, carb and tested with fuel tank cap off/open."

I agree 100% about not bothering to fool around too long with these carburetors--I have fixed/resold probably 15 lawnmowers/trimmers/blowers over past 5 years, often needing just a new carb . And I don't recall ever spending more than $20 for the part., often carbs are less than $10. As I recall this particular carb order included fuel lines, a bulb and a filter, all for only $10-12...amazing. I do feel bad supporting China though. Only carb rebuilds I bother to do are on small outboards...

So I am thinking if this is not an air leak or some other problem with the carb then it must be insufficient vacuum drawing from the CrankCase to the Carb. I believe this would behave similar to an air leak in the carb. A Leakdown Test would be the proper way to diagnose before just doing more "swapping parts" but again I don't have a tool for that...unless you know a cheap and dirty way to test that??? I think that oil seepage from the righthand seal is the best smoking gun I can go by.

Any other thoughts/advice?

Thanks again.
 

darenative

Twelve Pointer
From what i can see, the piston crown looks like the engine is running lean. If you are sure your carb settings are close and you dont have air leaks on that side, the crank seals would be my next item to replace.
 

41magnum

Twelve Pointer
this place says they talk about Husky mowers to blowers!
 

DuckyDave

Six Pointer
Thanks Mike, i tried this initially but didn't work, went back in and found it.

Hi All, here is something else i observed...below the muffler this plastic was melted...possible overheating??? If overheated could this have cooked the one Crankcase/Crankshaft Seal? Or the other way around, meaning a failed Crankcase Seal resulted in overheating? Photo is with cellphone now in jpg mode...20200503_061159.jpg
Change the type at Settings->Camera->Format.
 

DuckyDave

Six Pointer
this place says they talk about Husky mowers to blowers!
41magnum, thanks for pointing me to this other site. It has WAY more info and activity than the firum/site where i have been looking.

Darenative, interesting on this other site someone mentions a cracked Crankcase Seal causes a lean condition. All this seems to point toward one smoking gun--bad Seal.

BTW another thread at the other site indicates there is a small circuit board within Husqvarna coils (and this circuit board can go bad--or worse yet intermittent). Can anybody confirm they have seen/dissected such a coil/circuitboard?
 

nccatfisher

Old Mossy Horns
Contributor
Thanks Mike, i tried this initially but didn't work, went back in and found it.

Hi All, here is something else i observed...below the muffler this plastic was melted...possible overheating??? If overheated could this have cooked the one Crankcase/Crankshaft Seal? Or the other way around, meaning a failed Crankcase Seal resulted in overheating? Photo is with cellphone now in jpg mode...View attachment 44445
Overheating comes from running lean.
 

Mack in N.C.

Old Mossy Horns
Thanks guys, sorry I wasn't clear but replacing the carb was one of the first things I did:

"I have installed all new fuel lines, bulb, filter, carb and tested with fuel tank cap off/open."

I agree 100% about not bothering to fool around too long with these carburetors--I have fixed/resold probably 15 lawnmowers/trimmers/blowers over past 5 years, often needing just a new carb . And I don't recall ever spending more than $20 for the part., often carbs are less than $10. As I recall this particular carb order included fuel lines, a bulb and a filter, all for only $10-12...amazing. I do feel bad supporting China though. Only carb rebuilds I bother to do are on small outboards...

So I am thinking if this is not an air leak or some other problem with the carb then it must be insufficient vacuum drawing from the CrankCase to the Carb. I believe this would behave similar to an air leak in the carb. A Leakdown Test would be the proper way to diagnose before just doing more "swapping parts" but again I don't have a tool for that...unless you know a cheap and dirty way to test that??? I think that oil seepage from the righthand seal is the best smoking gun I can go by.

Any other thoughts/advice?

Thanks again.

only advise i can give right now it to not buy those cheap chinese carbs. you get what you pay for. they are crap.
 

BarSinister

Old Mossy Horns
I had one once do something similar and the muffler was clogged , not totally but enough. Can happen with improper 2 stroke mixture. But to me it sounds like carb issues. I just changed a carb on a push mower I have. It cut off one day, wouldn't start unless I opened the choke (???) then would run fine for a 5 minutes to 2 hours. Changed the carb and back to one pull start.

I had another that I tried everything on and ended up selling at a garage sale for $10. Only so much frustration I was willing to put myself through for a sub 200 blower.
 

DuckyDave

Six Pointer
I had one once do something similar and the muffler was clogged , not totally but enough. Can happen with improper 2 stroke mixture. But to me it sounds like carb issues. I just changed a carb on a push mower I have. It cut off one day, wouldn't start unless I opened the choke (???) then would run fine for a 5 minutes to 2 hours. Changed the carb and back to one pull start.

I had another that I tried everything on and ended up selling at a garage sale for $10. Only so much frustration I was willing to put myself through for a sub 200 blower.
I haven't tried running it with the muffler removed yet, although i did remove and inspect the muffler and the spark arrestor (separately). I might reassemble and try running with muffler off--i once had a Homelite blower with clogged exhaust port that ran poorly until i cleaned it.

I hear you on cheap Chinese carbs although they worked ok for me on several lawnmowers.

Thanks
 

Eric Revo

Old Mossy Horns
Contributor
Look at the intake and make sure it's not cracked or sucking air, sometimes that can be the culprit.
 

DuckyDave

Six Pointer
Look at the intake and make sure it's not cracked or sucking air, sometimes that can be the culprit.
Eric, thanks for the reminder--yes I believe a cracked intake would behave like this. But visual inspection doesn't reveal anything cracked either on the Intake portion of the Cylinder or on a composite material Carburetor Boot that press fits onto the Cylinder Intake area.
 

DuckyDave

Six Pointer
QBD2,

I hear ya about the free stuff!

I have learned the hard way that the trick is to find and work on the free stuff that nobody has even attempted to debug/fix because there COULD be an easy fix, i.e. low hanging fruit. But any free item that a reasonably skilled person has worked on is a whole 'nother level of challenge. First of all, it is making a bet that I am smarter than the previous fixer person. Secondly that fixer person might have screwed up something that wasn't broken/wrong in the first place! So that creates a second (or more) Root Cause that has to be identified/remedied.

I retired a couple years ago and I miss the technical challenges (but not the "people challenges") that I had at work. So working on small engines fills a void for me. And I get a great sense of satisfaction when I fix/resell something. On the other hand, it frustrates me greatly when I can't fix something (which is usually because I don't have enough firsthand SubjectMatter knowledge). Forums like this one help greatly.

Thanks for the input.
 

nchawkeye

Old Mossy Horns
Try spraying some Carb cleaner around the intake and shaft seal to see if it changes how it runs...That will indicate a leakage problem in that area....
 
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