Stihl leaf blower leaking from exhaust port

16 years ago

I have a Stihl bg55 leaf blower that at one time leaked gas out of the exhaust port. Upon doing some thinking before I wrote in, I wanted to give the most accurate discription of the problem before I wrote in.

Today I went out to my garage and noticed a very black, sooty fluid that had leaked out of the exhaust port of my leaf blower. Upon examining the stain on the floor, I came up with an almost sure theory that it was not accually gas because it would not had been so black. Iliminating the possibility that it has a faulty needle and seat. If this was the problem the leak would have continued until the tank ran dry. 2. The stain was dry, telling me that it only leaked for so long then quit. The only thing I can think of is that there was a buildup of unburned dirty oil somewhere in the motor. When I went to start the motor it ran just fine throughout the intire powerband with a normal idle. Could someone please tell me where this dirty black fluid could be comming from and how to eliminate this from happening again?

Featured Answer

HU-189792721

4 years ago

Thanks for the input...ill go over the settings ...then look at a synthetic oil mix...it has a new plug and filters are clean...will update ...thank you

Sort by:Oldest

Comments (11)

nevada_walrus
16 years ago
Unscrew the exhaust outlet from the muffler. You will find the spark arrestor screen is mostly clogged up from carbon build up. It wouldn't be long until it would not run worth a spit.

You need to secure this outlet nozzle and screen in a vice or vice grips, use a propane torch to heat up the screen to red hot and brush off with a wire brush. Do this away from any fuel or combustables as the hot carbon sparks brushed off could set something on fire.

This is caused from running at half throttle, dirty air filter or fuel mix that is old or has too much oil in it.
1saxman
16 years ago
OR, you had one or more instances of the needle and seat hanging open a little. Raw fuel/oil mix ran into the engine and out the exhaust port and through the muffler, picking up some black carbon. Add 1 oz/gal Marvel Mystery Oil or Seafoam to your 2-cycle mix in addition to the regular amount of oil. This will clean up the whole system and keep it clean. I don't think any repair is required at this time. All 2-cycle mufflers are full of black gunk.
Related Discussions
STIHL 420C Backpack Blower
Q
Comments (3)
You can check it if you want to;after you remove the screws that hold the muffler on(usually 2, could be more)you can tap it loose, carefully--there may be a gasket underneath,wich you don't want to break. Usually there's an outer shell,screen,maybe a spacer,and another outer shell(attached to the cylinder) .....After you remove everything,either pull the starter handle,or turn the flywheel,and look inside the port with good light,and you will see the piston move.When the piston closes the port fully,you can clean the port,if it does need cleaning.It will be black,but try poking the carbon with a plastic or preferably,a wooden toothpick, If you see flakes coming off,continue poking,scraping,to clean the carbon.Don't use anything harder than a hardwood pick;when you're done,check the screen to see if its clean also. ..........................There are many variations,to taking apart some of theese muffler's.,and some cannot be taken apart,but you can still look inside the port if you want to. Now this is the FUN part; After the port is cleaned,I start the engine to clear any particles left behind...................and let it run for about 10 seconds....................
...See More
Stihl model BR400 leaf blower
Q
Comments (3)
Aha: Check Fuel Filter 1st . Remove Jets , inspect all ok ? Clean Jets with Carb Cleaner Spray reinstall to 1-1/4 to 1-1/2 turns out . Also put some carb cleaner in fuel System approx 1 Oz. If diaphram within carb is ok you should be up and running within 30 Minutes . As always use Fuel Treatments for Storage and Annual Start up . As recommended by other Forum Members new Lines and Plugs as required during Routine Inspections. Let us know how you make out !
...See More
New backpack leaf blower suggestions.
Q
Comments (44)
Heres a good review of Tanakas back pack blower: 23 of 30 people found the following review helpful: 5.0 out of 5 stars Earning Respect, January 1, 2010 By Alan E. Schmidt "Monkey head" (Las Vegas) - See all my reviews (REAL NAME) This review is from: Tanaka Commercial Grade Gas Powered Large Backpack Blower Side-Mounted Throttle 65cc 4.3 HP 2-Stroke (CARB Compliant) TBL-7800 (Lawn & Patio) In one word "DOMINATING". The Tanaka 65cc TBL-7800 has made me king of the cul-de-sac. They now call me the blow king. Autumn. 2009. My Tanaka 65cc TBL-7800 arrived late in the afternoon. 4:16 p.m. A quick scan of the yards in the cul-de-sac revealed that the trees had left an abundance of prey all over. My adversaries, or as you would call them, my neighbors, were also surveying the battlefield. I locked eyes with my neighbor, Francis, I lowered my brow and gave him a "whats up" head nod. He returned my head nod with a demonic smile. Stupid french. It was on now. Oh Yeah. See you on the battlefield Saturday morning. What do the French know about blowing anyway. Saturday morning. 6:55 a.m. Garages opened. The gladiators took the field. We sized each other up. Jaws dropped when I turned to the side and they saw the Tanaka 65cc TBL-7800 strapped to my back. Thats right boys. Drink it in. I just brought a semi truck to a demolition derby full of Hyundais. We all spotted the new guy at the same time and smiled. He wore sunglasses instead of ski goggles. HA HA, hope he likes watery eyes.... amateur. 7:00 a.m. Let the battle begin. City ordinance says no blowers before 7. It was like the gates opening at the Kentucky derby. The action started quickly. New Guy - The TBL-7800 blew the sunglasses clean off his head. As he ran away I blew one of his flip flops off also. Like I said, amateur... Don't come into the wolf den wearing deer antlers, idiot. I took the sunglasses as a trophy. The flip flop ended up on the roof. He can kiss that one goodbye. Francis - The leaves were flying, hot air burned my skin. I sacked up and plowed forward. I knew he was limited by his extension cord. The end came quickly. He surrendered in less than 2 minutes. Imagine that, the French surrendering quickly. Who would have thought. I stood in the middle of my leaf free yard like a King. My scepter was the Tanaka 65cc TBL-7800. They lined up to kiss my ring and acknowledge the blow king. All except the new guy. We may have put him in therapy for awhile. The Tanaka TBL-7800 slayed them all that day. Hands down, the clear winner. I did get a little hot on the back. Wear a good shirt. I wore cut off jeans, tank top, knee high moccasins, and ski goggles. Wanted to look respectful when sporting the TBL-7800. No doubt I did it justice.
...See More
leaf blower repair
Q
Comments (2)
Assumming the carb is rebuilt correctly. 1) Take off the muffler to check the exhaust port for buildups. 2) Close the choke half way and rev it and see whether it help. If so, it is too lean or air leak. 3) Get a can of Deep Creep ( spray Sea Foam), run the engine until it is warm, spray along the seam between the cylinder and the crankcase and the lower crankcase. I think you have the same engine as the HomeScaper trimmer engine. I have one on hand. It has separate cylinder and upper and lower crankcase. Spray along the gasket to observe any bubble while running and reving to check for air leak. 4) Tighter the two screws of the carb to make sure it is tight. 5) If nothing help, check spark. 6) If everything seem fine. Then go back to the carb!!! You're screwed!!!!
...See More
yungman
16 years ago
Is Marvel Mystery oil that good?!!!! They have been around like....forever!!! I used in my car back in the hot rod days!!! It is an oil also? Does it has any problem using with Stabil, Mobil Racing 2T or Stihl Ultra?
indy452
16 years ago
Hmmmm, I have a BG55 and I'm pretty sure it has a diaphram carb and not a needle and seat type.

Sounds like an overly rich condition, and I'll bet that the stain was fuel. Sounds like too much fuel entering then washing out the exhaust onto the floor.
Whats the spark plug look like? Is it clean or wet and oily?
What ratio of fuel/oil do you run? Should be 40:1.
Have you turned any screws on the carb?

You say it ran good last but has it always?

Neal
whizzer75
16 years ago
Diaphram carbs have a needle and seat.
g-mann
16 years ago
After reading Neil's response,the problem got me thinking. At one point it ran like crap. No power and no high speed. I then tried adjusting the idle screw and both the High speed and Low speed screws with no results. Come to find out, the spark arrestor screen was plugged so I cleaned it and it ran just fine after more adjusting.I feel at this point it is likely the thing is running too rich and collecting unburned gas and oil in the muffler.It will collect a certain amount until it starts spilling out again. My question is this: Can anyone tell me the factory settings for all three adjustments so the thing runs normal again. I do not live above sea level and no it does not have a catalytic converter.
indy452
16 years ago
My bad, I was thinking float type.
Anywho, g-mann I tried sending you a PM but the postmaster keeps sending them back. I have the info from my manual on carb settings. I'll try later.

Neal
singlebbl
16 years ago
Are there any "tricks" to removing and reinstalling the muffler? Or is it just unscrewing the two bolts that hold it in place? I notice that there appears to be some kind of flexible rubber gasket material under the heads of the bolts.
HU-189792721
4 years ago
Similar issue ...I have a bg55 with oily residue clogging the spark arrestor...after cleaning ... it cloggs after 30 min of use at max rpm....i us 95 octane gas... standsrd certified 2 cyc oil ...2.6 oz per gal...unit 4 yrs old... use..1-2hrs per week...have another same model 2yrd old with no issue...it seems like its not burning the fuel / oil mix completely..anybody got any ideas
ssewalk1
4 years ago
721 , The most important issue is to ensure you have proper air / fuel ratio . This will ensure a optimium fuel burn . Your high and low jets should be set between 1-1/4 to 1-1/2 out from seated . Also your air filter must be clean to ensure a non rich fuel air mixture . Secondarily fuel filter and exhaust screen must be inspected and cleaned at least seasonally . Last but not least a Premium Synthetic oil will provide maximum engine protection with the least oily film and carbon accumulation . Your current ratio of 2.6 ounces of oil to a gallon of fuel ( 50:1 ) is the best ratio for today's new 2 cycle engines . I recommend Amsoil Sabre however Ultra or Opti- 2 are other fine oils . A new spark plug annually will provide a colour ( medium brown to tan ) indication of proper engine protection . Any darker and either to much oil or fuel !

Stihl leaf blower leaking from exhaust port

HU-189792721

Comments (11)

nevada_walrus

1saxman

Related Discussions

yungman

indy452

whizzer75

g-mann

indy452

singlebbl

HU-189792721

ssewalk1

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US