Has anyone replaced or cleaned a carb on a Sthil BR430 leaf blower?

JacksonRobertson
Picked one up from someone pretty cheap, $75.  Starts up fine but then dies after running for a while.  He didn't know what to do with it so I figured I could try taking it apart and starting with the carb give it a once over.
 
I dont see anyone on YouTube who has accomplished this, lots of videos on a lot of things but nothing around the carb.  Does anyone have any guides or pointers on how to get into it?  I know I need to take off the large panel and it is going to be mounted on the left hand side behind the air filter, but anything anyone can point to that would help.  

Hmmm, I done a lot Zama C1Q carburetors. There is very little that can be disassemble and most of the cleaning of internals are done with ultrasonics; No carburetor cleaners or compressed air as they are destructive on these carburetors.
 
The three different carburetors that used on this blower uses the same carburetor repair kit which is Stihl PN 7010 871 0222. The problem is most dealers don't stock it and some can't even get it. Most will just try to sell you a new carburetor instead.
 
Stens does have a kit that will fit . Their pn 615-441 per my internal notes.
 
As far a service guide here what Zama has on it.
http://www.zamacorp.com/d...lyservicing-as250.html
 
 
 

JacksonRobertson

AVBThere is very little that can be disassemble and most of the cleaning of internals are done with ultrasonics; No carburetor cleaners or compressed air as they are destructive on these carburetors.
 

 
Can you talk a little more about that?  What makes these different from the small ones I have normally seen?  Normally I just spray them down with cleaner and things start working once its all blown clean.  I cant expect to do that here?

No because there are delicate spring loaded rubber check valves. Many of which are under 2mm in diameter. Once one these check valves is blown out of position by compressed air or the rubber destroyed by the carburetor cleaner the game is over. These are none replaceable components. Once damaged it is a new carburetor time.
 
Now you are lucky if you haven't damage one yet.
 
Note: I have been cleaning and rebuilding these cube carburetors for over 12 years now. When I first started I too thought it was a simple as larger carburetors to clean these.  In last 8+ years I clean solely using an ultrasonic cleaner. I currently on my third machine as I had increase the tank as I added larger carburetors to list of carburetors I clean in one. These machines uses mainly soap and water to perform the cleanings.

That can be an ignition problem as electronic gets heat soaked they can fail. But really hard to advise on this the problem can be one several things that only an experienced 2 cycle tech can diagnose properly.
 
As for compression these unit usually in the 140+ psi range when in good condition.
 
As for those after market carbs it is hit and miss with more misses than hits. IF you are considering a replacement check with the Stihl locally as they are fairly reasonable on carburetors and not on the repair kits. I have seen carburetor to be only $10 more than kits at times.

JacksonRobertson
Okay I have hit a snag, so pausing for a bit.  I don't have a socket thin enough to get into the well for the carb cover:
 

 
That.  It's an 8mm nut according to the breakdown diagrams.  I have a couple of 8mm sockets but they are too thick to fit in there.  Need to go hunt around to see if any stores have something like this in stock.  I found this at Home Depot but it's not in stock:
https://www.homedepot.com/p/Klein-Tools-8-mm-Nut-Driver-with-3-in-Hollow-Shaft-Cushion-Grip-Handle-630-8MM/203310567
 
This says it might be in stock locally: https://www.harborfreight.com/metric-nut-driver-set-7-pc-69110.html
 
I can go check on that this weekend then if its what I need.

I got the driver set and the whole thing opened up in a a jiffy.  Inspected the carb, sprayed what I could, was gentle on the rest.  Put it back together.
 


Same spot, it starts up fine and works well but as soon as you pull the handle or pop the choke it revs up loudly and then dies.
 
Here is a video with sound that shows what now happens:
https://imgur.com/a/7hUjTFB Click it and then click the sound button on the top right of the image to hear.  Not sure why it's upside down.

Sten's website says I need to be an authorized dealer to buy the kit.
 
Will anyone sell to us commoners? 

This?
 
Stens 615441 Carburetor Kit Replaces Zama RB100 - Jacks Small Engines
 
I also found it on Amazon, I hate to use them but the shipping on Jack's make's it double the price unfortunately.  The "Sten's Store" as you mentioned on Amazon has the part.
 
That's not too bad.  I did call the local dealer and they did not sell any kits of carbs on hand for this model.  Would I replace the jets that come with the kit as well?  I didnt take any of those out when cleaning as I didn't have a way to get to them.
 
So as I was still messing around with it after reassembling it I started to muck about with the L and H screws.
 
Video here with audio again:https://imgur.com/a/Qm3VPNl
 
I am now able to get it to run with the choke off and in the RUN position.  Took way too long and too many pulls.  Now that it's doing that the throttle on the arm still has it shut right off.  No luck at all with that.  Does that mean the H screw is where my issue is now?  I have never adjusted a two stroke carb before so I am just turning things until something happens. I know L is the low speed one and when it's idling and the H is when the throttle is engaged.
 
If you watch the video with some sound you can hear it rev when I close the choke again and then go back to idle when it's back to RUN.  I gave the throttle a shot and it said nope.

Ordered the kit so I will try that out either later this week or on the weekend when I have a day off.
 
Do I need special tools to replace the pins and other small parts?  When I took it apart like the picture above shows I wasn't able to get anything else out that you don't see. 
 
Was thinking about the fuel filter as well.  Would that have anything to do with this or since I see the gas flowing is that good for now?
 
What do you mean by this part, I am not sure I understand:
IF you haven't the limiter caps you will within 3/4 of turn of the original adjustment.
 
What's a limiter cap?  What I did was just put a screw driver in the hole in the orange shell and start turning.  Nothing was working before so I figured I couldn't make it worse.  I will tell you these are turned much farther out from seated than 1 turn for L and 1 1/2 for H.  I did put them back to fully screwed in and started to back the L out to try to get it started, many more for the H but throttle isn't working so it's still not set right.

Okay thanks.
 
Is there anything I can do now or just wait for the rebuild kit to get here?  With the screws all mucked up which should I focus on?  The L or the H?  It wouldn't even start with the choke fully set when I had it screwed in and backed out only slightly.  I had to unscrew quite a bit more to get it to get going.