I've not operated on an 85, but here's one thing you may want to consider--try operating the throttle lever on the handle to the wide open position. This may allow a little extra carb movement on the mounting studs. Don't know it this will help but it's worth a shot.

 

dutch, ... I understand what you are suggesting. But, I've done that already. "full throttle" position gives more length at the carb, but not enough for it to slide off the end of the posts.

Thanks.

 

Double nut the studs and remove them or vise grip and replace. I highly recommned a new carb over rebuild. Late model carbs just never seem to rebuild well.
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Patriot, are you sure they are secured with a threaded fit to the block?

I thought that to be the case. However, I did use a ViceGrip on the bare shaft. The post rocked back/forth over a couple of degrees, and was "loose." This is why I made my comment that they may be L-shaped ends, being trapped between the block between the carb and the block. A parts diagram would be very helpful to know for sure what the ends of these posts looked like.

The block between the carb and the block is held in place with a couple of screws. However, access to them depends upon the carb being off first.

 

Roger,

Having not spent more than a minute looking at an 85, I'm not familiar at all with the throttle linkage from the handle. Possibly unhook linkage in handle assembly? Beyond that, I don't have much of a clue without having the blower on the workbench in front of me. On the other hand, manufacturers(design engineers) do some stupid stuff from time to time.

Maybe there's some secret that an authorized Stihl mechanic will share with you. It's too bad that Stihl doesn't want the consumer to have a look at a parts breakdown as they are sometimes helpful.

 

....It's too bad that Stihl doesn't want the consumer to have a look at a parts breakdown as they are sometimes helpful.

Bingo!!! This facet of Stihl is very frustrating to me.

 

That's one of several reasons I use and own Shindiawa equipment. I haven't seen enough of their equipment since the Echo/Shindiawa merger to determine if the quality/performance has changed.

 

I'm going from 20 year ago mental image. You should be able to squeeze to full throttle, hold the blade full open, release the trigger and the cable end extends out of the retainer on the arm. God this is impossible to put in words. Its kind of unversal to most brands. The carb return spring pressure is what holds the cable in the slot.
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Remove the remaining screws from the handle half/grip and you will be able to remove the throttle wire and then pull the carb without having to remove anything else. I would not rebuild a carb with that age and amount of use. Also consider replacing the fuel hose assembly and fuel stone at this time.
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First take compressed air and clean that thing so you can see what you have.My dealer had both the carb kit ($17.00) and the carb ($27.00) in stock.Guess which one I bought.

 

Thanks for the comments and feedback.

MowerMedic, I now agree with the handle disassembly to get the throttle wire out. That seems to be the only way.

I have another source of blower, so the pressure to get this one back in service has been eased. This means I can take it apart, get the numbers, get the parts, and put it back together. I hate taking the steel-to-plastic screws out multiple times (those in the handle). The risk of plastic failure is high. But, now that I can take more time, I need to disassemble and reassemble only one time.

Yes, I made some inquiries about carbs and G & D kits. I got a quote about the same that was mentioned here. So, putting on a new one seems like the way to go.

And, yes, it does need to be cleaned up. When I took it apart, I was hoping to quickly get the carb number, and put it back together, hence the lack of cleaning at that time. I didn't think I would even need to get this far.

Thanks again for the input, and responses.

 

I would check the fuel lines before you order anything. You may get away with a new line and a cleaning of the fuel screen in the carb.

 

Update: I had some time late this afternoon to take the project to the next step. This time, I took off the starter housing, and one half of the handle. This exposed the channel for the throttle wire, and allowed me to pull off the throttle trigger. It is hinged on a post, and captured between the two halves of the handle.

After getting the trigger and wire out, I was easily able to remove the Z-connection from the carb. Then the two hoses to the carb were taken off. The carb pulled right off the posts.

I believe I was right -- the posts are captured pieces with a hook on the bottom end. They are "loose" when I took the carb off, both in the transverse direction as well as the rotational direction.

Here are several pics, from the handle being split, the throttle trigger and wire being removed, and then the carb coming off.

After the carb came off, and I got it cleaned up, I was able to determine that it is a ZAMA C1Q-S68B. I've shown the places where the C1Q is stamped (deep down into the inset), and where the series number is stamped (albeit faint).

I have located a supplier and ordered a new carb (rather than a GND kit). BTW, after the last pic, the next stop was at the air compressor for some cleanup.

During my Google search, one entry came up near the top of the list:

http://www.lawnsite.com/showthread.php?t=256443

This is a thread more than three years old. But, the carb is identified in post #11. While on the goose-chase to find the information, it was right under my nose!!! I thought I had done a search, but apparently didn't look closely enough.

Perhaps all this information will help the next BG85 blower user needing to make a repair.

 

Roger.

Although, I've never had a Stihl down that far, my guess is that the two carb mounting screws are simply hex headed capscrews retained in hex recesses in the isoblock.

 

Roger.

Although, I've never had a Stihl down that far, my guess is that the two carb mounting screws are simply hex headed capscrews retained in hex recesses in the isoblock.

They are. That is why it is important to make sure they are indexed properly before you start tightening down the carb/filter assy nuts. I have seen more than one of these intakes cracked. Same on all of the FS/FC/HL/HT 75/80/85 series.

 

I know this is a very old thread, but I'm having trouble with this particular blower. It hasn't started or run well in awhile, so I replaced the carb with a brand new one today. It still won't start. Just won't turn over. Any ideas on getting it going?

B

 

Start with the basics. Fuel, air, spark. Then compression. Check for spark and add a spray of cleaner. You should get at least a pop. If not, check kill switch and coil.
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... It still won't start. Just won't turn over. ...

B

Do you mean by "won't turn over," it is locked and the crankshaft will not turn? Or, can you pull the cord, and it turns, but won't fire?

If the latter, is there any hint of combustion? Any small sign of "catching?" Or, it is just turning, but "dead?"

As suggested, what about spark? Do you have an inline tester to determine if a pulse is getting to the spark plug? If not, then perhaps you have a bad ignition module. How old is the blower? Lots of use, or just an hour each week?

 

My BG85 has started to degrade in performance and now does not run well enough to continue use. The pattern of "flameout," poor starting, and irregular power (fluctuations in rpms) tell me that the carb has degenerated diaphragms. It seems to me like it is not getting enough fuel. It is 6-7 years old, run daily for the season (mow/blow about 1,200 properties per season), and has been used hard for leaf work every Fall.

I wanted to get a G & D kit, but need to know the Zama carb number. Like all STIHL products, the only way to get the numbers is when the carb is off and one can find the stamped numbers on the existing carb.

When I went to take the carb off, I found the carb does not slip off the posts because of restraint by the throttle wire. It appears that the only way to slip the carb off the Z-connection at the end of the throttle wire is to rotate it, but this only can happen when the carb is off the posts. Sure, I can take a plier, or some tool, to bend the wire, but I am concerned about getting the wire out of shape, never to be fitted up right upon remount.

The attached pics show the carb in the fitted position, then slipped down the posts to the extent allowed by the wire. The sliding down the posts is not far enough for the carb to be removed. I think it needs another 3/8" or so.

I though that perhaps the posts could be unscrewed, removed, and then the carb would be free to rotate as necessary to get the Z-connection unhooked. But, even though the posts seem a bit loose to unscrew, they seem "hard" connected. Perhaps the end of the posts have an L-shape, engaging in a slot, and are not screwed into the engine head.

I seemed to be at a "chicken-egg" stage. I can't get the carb off, so can't get the numbers to get a G & D kit.

Anybody know how to resolve this dilemma?

Pic 1 is the carb slid down the posts to the normal postion. Pic 2, 3 and 4 show the carb slid up the posts, with the throttle wire still engaged in the throttle.

Thanks.

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you gotta take the 3screws off the handle then you can get to the trigger and take it right apart the right way

 

Holy moly that thing is filthy, no wonder it's not running right...
Don't be like every other shop mechanic and just replace one part you think will fix it, look at how dirty it is... I used to buy them in that condition (all caked and dirty) for like $30 and fix them all up again, couple of hours labor, blam $150 blower.

So I would give that thing a complete tear down (except the engine, take it out but keep it together) to every last piece and clean each and every part until it's squeaky clean.
You can get carburetors for these on Ebay for like $15, make sure to get one with gaskets.

Here's me doing one of my own...
Actually it might be parts for two?
But anyway take it all apart and clean it all up real good, throw a new carburetor and gaskets, new air filter, new spark plug, replace the fuel filter, might need new fuel lines, see if the recoil rope needs replacing, what about the vacuum vent on the tank... You might can get away with spraying a lot of compressed air into all the nooks and crannies, but I would take it all down to its components.
That or just buy a new one.

 

You sir have FAR too much time on your hands!! LOL

 

I know I am day late and a dollar short on this one here, but I just had to do this with my BG85 three days ago. In order to remove the throttle linkage, the original poster could have:

1. Removed airbox. (I removed starter case for easier access to the general area as well)
2. Pulled throttle while sliding the carb back towards the end of the studs
3. Gently pulled up (or push up on underside of throttle linkage) on bent throttle linkage where it connects to throttle plate lever
4. Finished pulling carb off studs.