# BG86-C issues



## LonestarStihl (Sep 26, 2016)

I took a Bg86-C blower to my dealer who for $20 shop fee would look it over and see what it took to get running. Bought the blower for $4 so I'm not worried about its condition too much. Dealer called and said it had no compression and needed. Ew piston and cylinder...in its condition that's not happening. 

The problem is I and another guy in the shop were very surprised at this because it "felt" like it at least has some compression. I have my own gauge on the way now to do my own test but the drop test so to speak held for a few seconds by the pull cord fine. I took pictures through the cylinder for y'all to take a gander and see if y'all see anything unusual for me. 


























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## LonestarStihl (Sep 26, 2016)

Anyone? 


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## GrassGuerilla (Sep 26, 2016)

Don't see anything that should keep it from running in the pics. Can you feel that vertical line on the piston? I'd give you $24 for it.


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## diezelsmoke (Sep 26, 2016)

Piston looks fine. How to determine if the ring is fine, take a small screw driver and press on the ring and if you feel a spring to it, it is fine.


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## LonestarStihl (Sep 26, 2016)

GrassGuerilla said:


> Don't see anything that should keep it from running in the pics. Can you feel that vertical line on the piston? I'd give you $24 for it.



If I can't get it running then it'll be a deal if you're serious. I'll let you know. I couldn't feel it but I'll try again. Gauge should be here in a couple days so I'll hook that up too


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## LonestarStihl (Sep 26, 2016)

diezelsmoke said:


> Piston looks fine. How to determine if the ring is fine, take a small screw driver and press on the ring and if you feel a spring to it, it is fine.



Thanks I'll check that tomorrow


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## LonestarStihl (Sep 29, 2016)

Haven't had time to check the ring yet. It I got a gauge and it maxed at 100psi. Is that decent for a blower? I figured it should at least run at that level.






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## diezelsmoke (Sep 29, 2016)

Probably would run with that compression, if you have spark, put a beer cap full of gas down the plug hole and see if it fires. Also since you know nothing about this blower make sure the stop switch is tried in both positions and if it feel goofy make sure it is operating properly.


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## ANewSawyer (Sep 29, 2016)

Hmmm, that is low. But it should start like diziel said. Hey, did you have the choke off when you did the test?


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## LonestarStihl (Sep 29, 2016)

Hmmm I didn't check to see if the choke was on or off but I'd put my money on it being off. I'm at work now but I'll try it with the choke on tomorrow and try the bottle cap test. I'm thinking its having a fuel issue because the primer bulb will not fill up. I can hear it pushing air out but it never bring fuel in to prime


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## ANewSawyer (Sep 29, 2016)

I think the choke is supposed to be off.


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## LonestarStihl (Sep 29, 2016)

Oh well it was. I'll try it both ways for the heck of it. Not hard to do. I do still need to check the rings but the pressure was holding at 100psi. I check the Stihl website and it states the blowers are normally a minimum 110psi but could vary so it doesn't seem too far off. Could be the gauge? It's brand new off the shelf but I need to check it with some air compressors I guess. 


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## ANewSawyer (Sep 29, 2016)

That guage is a problem. Actually, the adaptor it is to long. If the schrader valve is high up, it enlarges the combustion chamber and reduces compression. Post the model of the guage or a pic of the location of the scrader valve. Is it under your thumb in the pic? The schrader valve should be near the pressure release button. I bet that is your problem.


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## ANewSawyer (Sep 29, 2016)

You need to use a short adaptor, it screws directly into the plug hole and has a barb on it. That rubber one is giving you a false reading. I almost guarantee it.


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## LonestarStihl (Sep 29, 2016)

That's a stock photo of mine. I just plug and played with it. The release valve is directly under my thumb yes. As for the valve I am not quite sure


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## LonestarStihl (Sep 29, 2016)

Did I get a bad gauge or am I using the wrong pieces?


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## ANewSawyer (Sep 29, 2016)

Wrong pieces. The ones that are in the upper left of that photo, how do they attach to the guage?


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## LonestarStihl (Sep 29, 2016)

They attach to the short tube which has a quick connect into the tube connected to the head unit. The smallest piece fit perfect into the plug hole. I thought it was all good to go. I pulled it until it maxed out at about 8 but I did 12 to verify


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## ANewSawyer (Sep 29, 2016)

Hold on, I will find a pic. Wrong pieces.


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## ANewSawyer (Sep 29, 2016)

http://www.2040-parts.com/snap-on-compression-tester-6pc-set-kra-124a-i606249/

The second pic, of the head of the guage. See the adaptor to the medal of the head? That is what I am talking about.


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## LonestarStihl (Sep 29, 2016)

So you can put the plug end directly into the head unit?


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## ANewSawyer (Sep 29, 2016)

Right! There is a video I need to find but won't get until later tonight. I will post it if I can find it.


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## LonestarStihl (Sep 29, 2016)

Awesome I appreciate all your help. I'm thinking compression isn't my issue. Is the adapter an aftermarket thing I could maybe put on or should I return this one?


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## backhoelover (Sep 29, 2016)

i have had alot of them blower come in with coil problems. the coils has stages in them etc. i had them spark not run with everything else good . not run at it full throttle etc. what about the gas pour in plug hole etc,did you get it to fire. also the spark arrester screen is known for clogging up on that model just take it out and throw in trash and put the tip back on , i have also seen alot of dirt dabbler building a nest in the tit that you screw off the muffler to get the arrester screen out


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## backhoelover (Sep 29, 2016)

there is a tech bulletin about coil change. i cant get it to load up. new coil number is 4241 400 1307 which should be stamped on the coil if it has been updated . but you need to do some checking before going and buying a coil


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## LonestarStihl (Sep 29, 2016)

I haven't had time to do the gas pour in test yet I will do it probably tomorrow morning. How do you test the coil?


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## LonestarStihl (Sep 29, 2016)

I did use an inline spark tester which showed to be receiving a charge 


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## LonestarStihl (Sep 29, 2016)

backhoelover said:


> i have had alot of them blower come in with coil problems. the coils has stages in them etc. i had them spark not run with everything else good . not run at it full throttle etc. what about the gas pour in plug hole etc,did you get it to fire. also the spark arrester screen is known for clogging up on that model just take it out and throw in trash and put the tip back on , i have also seen alot of dirt dabbler building a nest in the tit that you screw off the muffler to get the arrester screen out



I check the spark arrestor screen but it seemed open I will probably remove it anyways. It will not turn over at all. The only thing I can see is the plug probably needs to be changed and the air filter. But the main concern I have is the primer bulb not filling. Maybe build up in the carb somewhere? I'm a rookie and I'm enjoying earning all this. It started as jut a whatever project and now I'm into it and want to get it going. 


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## ANewSawyer (Sep 29, 2016)

You mean won't start when you say won't turn over?

I would replace the carb whole, I believe that an OEM carb might be under $30. New fuel lines, air filter, spaker and fuel filter.


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## LonestarStihl (Sep 29, 2016)

ANewSawyer said:


> You mean won't start when you say won't turn over?
> 
> I would replace the carb whole, I believe that an OEM carb might be under $30. New fuel lines, air filter, spaker and fuel filter.



Yes it won't start. When you pull you can here the piston compress air but never even tries to fire. I hear they were about 50-60 but I'll check with my dealer. They owe me one anyways for telling me there wasn't compression when there is 


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## ANewSawyer (Sep 29, 2016)

Here is your problem: 

That adaptor I mentioned has a schrader valve at the end. I didn't realize it until now!


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## ANewSawyer (Sep 29, 2016)

Nah, don't pay that much. http://www.ebay.com/itm/New-Carbure...647071?hash=item1eaa81b8df:g:eqEAAOSwxp9W-PAm

Infact, don't go back to that dealer. Did you have to screw a hollow adaptor onto the lower hose to do the test? Like what he was talking about in the video? I see I was wrong about some of what I said, but I think we are on the right track!


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## LonestarStihl (Sep 29, 2016)

ANewSawyer said:


> Nah, don't pay that much. http://www.ebay.com/itm/New-Carbure...647071?hash=item1eaa81b8df:g:eqEAAOSwxp9W-PAm
> 
> Infact, don't go back to that dealer. Did you have to screw a hollow adaptor onto the lower hose to do the test? Like what he was talking about in the video? I see I was wrong about some of what I said, but I think we are on the right track!



Watched the video and that explained it all. So it is reading low because I'm using the exact set it said not to which was helpful. So really it's pulling good compression


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## LonestarStihl (Sep 29, 2016)

What gauge do y'all use for testing? The craftsman doesn't have the schrader valve fitting. I don't know if I can buy a fitting for it. Seems like I just need to shop around to find one that works. Shame because I liked the craftsman one


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## GrassGuerilla (Sep 29, 2016)

The Chi-com carbs work fine on those. Been running one for a couple years now. Replace fuel lines with OEM and I'd wager it'll be good to go.


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## LonestarStihl (Sep 29, 2016)

Yeh I figure at $16 if it lasts a few years I'm good. I don't want to throw a bunch of money at it because it only cost me $4 up front


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## LonestarStihl (Sep 30, 2016)

I looked at the compression tester again because I was thinking about how it has a field service kit which included a replacement core. The short adapter tube has a schrader valve on the end right before the smaller adapter goes on.





So there actually is a schrader valve then. Now is it the extension upon extension that throws it off or the tubes themselves? I'm just trying to greater understand what actually make it read low if there is a valve in there. I will try the bottle cap of gas in the morning and check some other stuff


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## 95custmz (Sep 30, 2016)

Your adaptor is throwing off the readings. Like gas guerilla said, replace your fuel lines. I bet if you'll look, you'll find that the one for the primer bulb has disintegrated or has a hole in it, which is why it won't prime.


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## ANewSawyer (Sep 30, 2016)

The hollow adaptor is what is throwing the readings off. I had to rewatch the video, as I hadn't realized that the valve was actually in the end of the adaptor, till I looked at mine last night.

I have a vintage snap on tester I got off Ebay. I have only used it once or twice. I guess I should check it with my compressor.


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## LonestarStihl (Sep 30, 2016)

I'm going to take my tester back since I'm using it primarily on small engines. Is buying a used snap on tester I'll advised since there is no warranty or is it good enough that I'd be alright?


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## ANewSawyer (Sep 30, 2016)

That is what did. You could price a new snap on guage kit but I bet you wouldn't like the price. Why not first try to find the adaptor I am using by itself? It is an M26 (metric). I will get the full deminsions later.

If you do get the Chinese carb, open it up and check out the insides before you run it. Just to make sure that there isn't a problem. I had one with a misplaced screen.


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## LonestarStihl (Sep 30, 2016)

ANewSawyer said:


> That is what did. You could price a new snap on guage kit but I bet you wouldn't like the price. Why not first try to find the adaptor I am using by itself? It is an M26 (metric). I will get the full deminsions later.
> 
> If you do get the Chinese carb, open it up and check out the insides before you run it. Just to make sure that there isn't a problem. I had one with a misplaced screen.



Well I paid over $70 for mine so buying another adapter and whatever else would get me close to 100. I might as well find a good used snap on for that. I'm going to check a couple of Stihl dealers to see what OEM carb will cost me first then I'll go with the communist carb


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## ANewSawyer (Sep 30, 2016)

I think I paid a hair over $50 for my tester, four adaptors and some misc stuff. On the bay.


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## LonestarStihl (Sep 30, 2016)

ANewSawyer said:


> I think I paid a hair over $50 for my tester, four adaptors and some misc stuff. On the bay.



I'm starting some searches on there to monitor for some good stuff


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## LonestarStihl (Sep 30, 2016)

diezelsmoke said:


> Probably would run with that compression, if you have spark, put a beer cap full of gas down the plug hole and see if it fires. Also since you know nothing about this blower make sure the stop switch is tried in both positions and if it feel goofy make sure it is operating properly.



Alright I did a small capful into the plug hole and let er rip. It was a success! It fired up and puttered out as I would expect with little gas. So that points to carb and fuel lines correct?


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## ANewSawyer (Sep 30, 2016)

Yes, it would point toward carb and lines.


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## LonestarStihl (Oct 1, 2016)

Another update for all who have helped. I haven't been able to go by another dealer yet to ask about parts so I decided to look inside the carb. It looks nice and clean so I checked all my lines. Couldn't see any issues so I actually just filled the gas tank until there was no air. I started pumping the bulb only to find gas was coming out of a hole in one of the lines. So it would appear the gas line is causing it to lose suction


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## ANewSawyer (Oct 1, 2016)

The carb can be clean but what do the diaphrams look like? Are they hard and stiff or soft and flexable?


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## LonestarStihl (Oct 1, 2016)

ANewSawyer said:


> The carb can be clean but what do the diaphrams look like? Are they hard and stiff or soft and flexable?



Diaphragm being the rubber gaskets on each side? I'm not savvy to all the technical terms. If so they appeared soft and flexible but I didn't pay as much attention


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## GrassGuerilla (Oct 1, 2016)

txtroop said:


> Another update for all who have helped. I haven't been able to go by another dealer yet to ask about parts so I decided to look inside the carb. It looks nice and clean so I checked all my lines. Couldn't see any issues so I actually just filled the gas tank until there was no air. I started pumping the bulb only to find gas was coming out of a hole in one of the lines. So it would appear the gas line is causing it to lose suction
> 
> 
> Sent from my iPhone using Tapatalk


As I said before, fuel lines...

As to the comp tester. It's all relative. If having an exact compression is important to you, find either the right adaptor, or buy the cheapo tester from Baileys (site sponsor). I've had mine a couple years now and it seems to be fine. Alternatively, accept that your tester is giving a falsely low number. (Wild speculative guess here), but I'd bet your blower is closer to 140-150 actual psi. For me, I could live with that. Or send it back, get the Baileys unit and pocket the $20-30 difference.


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## ANewSawyer (Oct 1, 2016)

The diaphrams are the thin pieces that take most of the carb space when you take off the covers. The gaskets just go around the edge.


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## LonestarStihl (Oct 1, 2016)

GrassGuerilla said:


> As I said before, fuel lines...
> 
> As to the comp tester. It's all relative. If having an exact compression is important to you, find either the right adaptor, or buy the cheapo tester from Baileys (site sponsor). I've had mine a couple years now and it seems to be fine. Alternatively, accept that your tester is giving a falsely low number. (Wild speculative guess here), but I'd bet your blower is closer to 140-150 actual psi. For me, I could live with that. Or send it back, get the Baileys unit and pocket the $20-30 difference.



I'm going to return the craftsman one and find a decent price on a snapon on eBay. I found a decent one now I'm waiting to see how the bidding goes. If I'm going to have a tester that's off then I'm. It paying 70+. I'm going to do the fuel lines first and if it runs I'll leave it alone. I'm not going for gold on it just silver will do


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## LonestarStihl (Oct 1, 2016)

ANewSawyer said:


> The diaphrams are the thin pieces that take most of the carb space when you take off the covers. The gaskets just go around the edge.



I didn't completely disassemble the carb yet. I'll check it next


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## LonestarStihl (Oct 20, 2016)

Alright gents I haven't forgotten y'all and I needed to update. I got fuel lines and installed. Bulb filled with gas and it started on the 4th pull. It did not run well so I let it go at idle speed and slowly give it gas and it seemed to build up speed slowly. The muffler appeared to get very hot fast as it ran less than a minute and seemed to smoke a tad but from heat. I cut it off and my 3 year old got but as he tried to help at the muffler shroud. I cannot get it to run again except for a short bit in full choke. I ran compression test on it again and now it will not register any compression. Guidance?


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## LonestarStihl (Oct 20, 2016)

Oh and I did get a used snapon compression tester off eBay. I've checked it on my Husky 450 and it shows 140psi so I'd imagine it's good to go. It has separate tubes with schrader valves on the end of each so no further adapters


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## diezelsmoke (Oct 20, 2016)

The smoking is because the engine was flooded and needs to just get cleaned out, let it run a while longer and adjust up the H side of the carb, probably a 1/4 counter clock and see if that improves, may have to go more. Might want to bump up the idle temp. to help in the process.


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## LonestarStihl (Oct 20, 2016)

diezelsmoke said:


> The smoking is because the engine was flooded and needs to just get cleaned out, let it run a while longer and adjust up the H side of the carb, probably a 1/4 counter clock and see if that improves, may have to go more. Might want to bump up the idle temp. to help in the process.



Thanks. I was leaning towards carb needing adjusted and maybe some burn off. It was in rough condition when I got it so I figured that could be a possibility as well. I'll do that tomorrow. Thanks!


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## LonestarStihl (Oct 21, 2016)

So it hit me today that the compression tube I bought may not have come with a valve installed. Low and behold I was correct. So I need to find schrader valve cores and a tool. Do y'all know if it's the same size core as a tire?


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## LonestarStihl (Oct 21, 2016)

Got it running but it doesn't feel like it has much too end. It stalls if I try to go to fast on it sometimes. I have adjusted the low speed but then it feels as though it'll be good for a while and changes. The top end really is where it seems to be missing he power


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## ANewSawyer (Oct 21, 2016)

Sounds rich to me but I am on a tablet with cheap built in speakers. I would pressure and vacuum test, if it were me to make sure there isn't a leak. Optional, if you want to. But that is the only reason I could think of for the high speed changing. Unless, you haven't rebuilt or cleaned the carb yet. If you haven't, I would definitely open the carb and clean it with spray carb cleaner.

Also, how old is the fuel you are putting in it?


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## 95custmz (Oct 23, 2016)

I had similar problems with my blower. It ran a little rich, therefore, I was cleaning the muffler once a year. But once I did the muffler mod, adjusted carb, and changed the spark plug I have not had problems with it. I believe the correct spark plug for yours is NGK CMR6H or the equivalent.


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## LonestarStihl (Oct 23, 2016)

ANewSawyer said:


> Sounds rich to me but I am on a tablet with cheap built in speakers. I would pressure and vacuum test, if it were me to make sure there isn't a leak. Optional, if you want to. But that is the only reason I could think of for the high speed changing. Unless, you haven't rebuilt or cleaned the carb yet. If you haven't, I would definitely open the carb and clean it with spray carb cleaner.
> 
> Also, how old is the fuel you are putting in it?



I do need to at least clean the carb. I was considering the 16$ eBay carb to just replace it. The muffler is pretty bad shape should I change it or will it make a difference? I'm using trufuel and it's not very old.


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## LonestarStihl (Oct 23, 2016)

95custmz said:


> I had similar problems with my blower. It ran a little rich, therefore, I was cleaning the muffler once a year. But once I did the muffler mod, adjusted carb, and changed the spark plug I have not had problems with it. I believe the correct spark plug for yours is NGK CMR6H or the equivalent.



What kind of muffler mod did you do? Mine is all rusted up from who know what the person before me did


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## ANewSawyer (Oct 23, 2016)

A lot of muffler rust because there aren't stain less steel. Just rip the cat out or punch a hole in it. I bought one of those ebay chinese carbs for my EB802 but I am not terrible impressed with it. It does work but the internal screen was not placed properly in the carb body, which would have allowed dirt into the carb. Also, a lot of flash internal. Which could break of, maybe, and create a big problem. I cleaned the factory carb, bought the small d tool and am putting it back on. The gaskets and diaphrams were good.


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## LonestarStihl (Oct 23, 2016)

ANewSawyer said:


> A lot of muffler rust because there aren't stain less steel. Just rip the cat out or punch a hole in it. I bought one of those ebay chinese carbs for my EB802 but I am not terrible impressed with it. It does work but the internal screen was not placed properly in the carb body, which would have allowed dirt into the carb. Also, a lot of flash internal. Which could break of, maybe, and create a big problem. I cleaned the factory carb, bought the small d tool and am putting it back on. The gaskets and diaphrams were good.



Alright I'll stick with original carb and just clean it real well. I may play around with the muffler and open it up a slight bit for giggles


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## 95custmz (Oct 23, 2016)

I soaked the whole muffler in carb cleaner overnight to clean off carbon build up. I removed baffle and opened up the muffler opening at the cylinder exhaust port with a router bit to let the engine breathe better. You will need to adjust the carb as the air/fuel ratio will change once you do the mod.


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## LonestarStihl (Oct 23, 2016)

95custmz said:


> I soaked the whole muffler in carb cleaner overnight to clean off carbon build up. I removed baffle and opened up the muffler opening at the cylinder exhaust port with a router bit to let the engine breathe better. You will need to adjust the carb as the air/fuel ratio will change once you do the mod.



Great I'll try that out on my next days off. Worst thing would be I have to buy another muffler if I screw it up somehow .


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## 95custmz (Oct 23, 2016)

Let us know how it works out.


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## LonestarStihl (Oct 23, 2016)

I will for sure. I'm kinda having fun with it. It'll still blow alright right now. But it's not running well and I can tell it's not putting out all it's got


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## 95custmz (Oct 23, 2016)

You'll be amazed at what a muff mod will do. The EPA has such strict regulations these days. With a little bit of tinkering, you can get your chainsaw, blower, motorcycle, etc. to run extremely better with a better flowing air filter (K&N), muff mod, carb adj., timing, etc.


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## LonestarStihl (Oct 23, 2016)

95custmz said:


> You'll be amazed at what a muff mod will do. The EPA has such strict regulations these days. With a little bit of tinkering, you can get your chainsaw, blower, motorcycle, etc. to run extremely better with a better flowing air filter (K&N), muff mod, carb adj., timing, etc.



Yeh I found the tool to take the limiter caps off on eBay. I haven't become that intense yet but I'm sure I'll get there


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## ANewSawyer (Oct 23, 2016)

Just wait till backhoelover gets ahold of you. I have never seen so many carb tools in my life!


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## LonestarStihl (Oct 23, 2016)

ANewSawyer said:


> Just wait till backhoelover gets ahold of you. I have never seen so many carb tools in my life!



so he is the carb guy? It amazes me the equipment some of y'all have  I have tool and saw envy


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