Picked up a used BR 430 - wont start.

FredBacher

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1. 0.5mm plug gap sounds small. Hope this is the OEM recommendation. - Yup, this is right out of the Sthil manual.
2. I don't see much smoke when it's running. You said you put Stihl oil in. How much oil did you dump into the gas? - 1 gallon of ethanol free fresh gas to 1 little bottle of sthil mixture.
4. You said you didn't want to put a lot of money in it until you hear it run. I've seen several videos of it running. - $100 on a carb for this old machine is a quarter of a price of a new machine. I could try putting the original back on if I can figure out how to stop it from leaking.
6. I'll fess up and tell on myself. Is there any chance you are operating the choke lever the wrong way? Yup I'm guilty...... LOL - I sure hope not. Looked right when I had the air filter cover off.
7. Does it have a strong spark? Get a spark tester and see. Or ground the plug on the block and check it that way. Make a video of your spark test. - I have a Harbor Freight spark tester that lights up but its not a very bright test kit, whenever I use it on lawnmowers and such it needs to be done in the dark, this one lights it up as well. I don't know if my camera will pick up the video in a dark garage.
8. Muffler seems wide open. Look elsewhere. - This morning I decided to have one more go at it, took off the entire muffler to see if it would run without it. It does, same issue though. Despite being loud enough to wake up the entire neighborhood when I was running it with no muffler same exact thing happened, so thats not the problem.
9. How about a vacuum leak at the carb? Most guys over torque those tiny bolts that secure the carb and warp that black block slash manifold deal. - The two tiny screws that hold the carb on?
10. Order new exhaust gaskets to replace the one that crumbled. - Can it run with no exhaust gasket at all?
11. Strip it down to verify intake and exhaust ports IN the block are clear. Might need to decarbon that little fella'. - So you're talking about taking off everything leading into the engine block and checking the other side?

The machine now starts up super easy, one of two pulls max, it's great. No matter what I do though, throttle kills it. For giggles I also took off the fuel filter (desperation) to see if maybe that was causing the engine to be starved of fuel. Same issue. I am going to put things back together and check into the carb again, the post above yours has the air test, I'll guess I will do that now, turn L all the way in and see if anything comes out the H.

I wonder if someone will buy this for $100 and I'll cut my losses.. I will try the next few suggestions today and see what happens.

It's just that the trigger kills it so quickly, it doesn't even try to rev up, there isn't even an attempt. Pulling it just shuts it off immediately. $100 for a Sthil carb still scares me as I wont be able to get my money back on that if it doesn't work. I have used a lot of knock off carbs before and have had issues, rough idling, never really perfection, but at least enough to get the various mowers and edgers and stuff running to the point where they were functional. Having this be this bad is something new.
 

FredBacher

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Again, I'll ask.
Is the primer/purge bulb hooked up correctly?
It can be hooked up backwards.

It's hooked up like this.

UKsk1Md.jpg


And, did you ever look at the piston on the intake or exhaust side?

That part I don't know how to get to. How do I see the piston?
 

Fish

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This looks like a decent video.
 

Fish

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To see the piston, one takes off the muffler and the intake, or on most, the piston skirt can be seen by just looking into the intake with the carb removed.
 

FredBacher

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This looks like a decent video.

Purge bulb! I learned something new from that. I had no idea.
Okay, so with that, then yes, I have the purge bulb hooked up correctly. Short side (In) connected to the carb, the long side (out) connected to the line going to the fuel tank.

I went and found the piston now too while the muffler was off. Here is a video for you. There is no easy to see scoring or scratches, it looks very smooth, goes up and easy, and appears to be coated with a proper amount of oil to keep it moving very smoothly.

Click here: Link to the video

 

Fish

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Hard to see the other side, from what I can see, it looks a tad rough, like some dirt ingestion. Look at the other side to see the piston.
 

FredBacher

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Haven't been around for a while but have a potentially exciting update.

While out there putzing around with it as always, I went back to the original carb after taking it apart and screwing it back together again, a large shock was felt, hand was on top of the spark plug rubber boot. Opened it up and didn't see any frayed wires but added a few inches of electrical tape to the connection point where the wire reaches the rubber.

It started.

Pulled the trigger.

It blew full force.

Was able to walk around with it for a while blowing things around.

Eventually it died.

Still, progress? I got it going a few more times, eventually it now dies after blowing for a while but this is a huge change from before of when any attempt to touch the throttle kills it instantly.

Thoughts?
 

Born2Mow

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Regular-grade pump grade Ethanol fuel will gum up a carb and block passageways during even short storage. If you can consistently get the engine to run, then simply adding a fuel system cleaner in with fresh fuel will sometimes clear the last remaining issues. I use StarTron myself, but others here have their favorite cleaners/fuel conditioners.

Put in a half tank of gas-and-cleaner, take it to an out of the way location so you don't have to listen to it, and simply allow it to run out of fuel. That's going to cost you about $2 and take nearly zero effort. What have you got to loose ?
 

FredBacher

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I only am using ethanol free after cleaning the carb and using the new one. It's sold everywhere in Florida, its very convenient.

Adding the cleaner to what I have in there now might flush out other parts of the system?
 

Born2Mow

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Then the interior of the carb is clean, but the tank, lines and filters will also be coated and similarly clogged. You can either clean or replace. Replace means getting the parts, then a lot of labor to remove covers, cut lines to the correct length, and fish filters into the tank.... which you may ultimately need to do.

On a customer job where you need to guarantee all the work, then go everything new. But on a personal job, I start with the simplest way first.
 
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