My new (OLD) BR600, questions

[WildnCrazyGuy]

Need help. Idle issues. But seems to respond and blow hard as it should. Trying to figure out what this means.

"The upper edge of the inlet control lever must be flush with the top of the carburetor body." A? or B? or ???

I think A, because I think that's where it's closest to now, but didn't want to start bending that puppy too much. I haven't looked at it since the other night, and I can't recall where exactly it was sitting, but just looking for some clarification. Thanks!

Also, when I looked on the carb, I didn't see really any markings except for Stihl. I know it's probably a Walbro, or more likely a Zama if it's a BR600, right? Guesses? Still looking for an IPL. (shhhhh)

 

[rmh3481]

When you look across the casting or use a straight edge you can set the lever height from there.

See if this helps,
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[Brad101]

The answer is "B", and it is a Zama carb.

 

[WildnCrazyGuy]

Thank you Brad. I just got back in from checking it and to my surprise, it was a hair under flush with B as you stated. So close, literally a hair under, so I didn't mess with it. But looking at it with the eye, I wouldn't have guessed it. I put the straight edge on it and no more optical illusions. Thanks again.

So, the metering lever is good, carb has been through and seems clean as a whistle. (was actually a little dirty on the pump side, but has been thouroghly cleaned as good as I can with the spray carb cleaner. And yes, trip to the dealer tomorrow to get a new fuel filter. Although the current one looks great. Was probably changed by previous owner, but no history, so to be safe...)

One thing I notice, is that when I press the primer, I don't get a bulb full of fuel. I only get approximately 1/3 full, AND it fills to the point where the line comes into the bulb. Sort of level with that side of the carb. Hard to explain, but doesn't want to fill the bulb as I'm used to. I read something about a check valve going bad in these carbs. Anyone confirm or deny? If confirmed, is my only option to purchase a new carb? AND, could this be my source of issue for idle problems? A stuck/broken check valve on the primer?

 

[WildnCrazyGuy]

Sorry about the size and lighting, cellphone pic, but I finally got to run my BR600 last night. Seemed ok, would idle down allright, not great, probably 8-10 seconds before it settles down ok. I'm apparently running rich and carbon is flying. I've made a call to my local Stihl deler this morning to get me some of that decarbonizing stuff. I bet the previous owner never heard of Ultra.

Couple of questions. Brand new plug and spark arrestor screen all very black. Run only about 30 minutes. Would the decarbon procedure help this or am I still running rich? Fresh 89, Stihl ultra by the way.

Idle still iffy. I can get it to idle ok at 2300, but I try to tach it at 2500, just barely turn (maybe 1/16-1/8) to bump the idle to 2500 and it jumps straight to 28-2900. So I can either get a good consistent 2300 or 2800, but nothing in the middle. The question is my WOT max rpm seems high as well. It's maxing at 7600. I think I read this blower should be around 7200. H is against the stop out, should I pull the limiter and see if I can get it down to 7200ish? But it looks like it's already running rich...

What do these running symptoms seem to indicate? Carb issues, fuel line issues, heavy carbon buildup, air leak(s)... Thanks.

 

[WildnCrazyGuy]

Well. I broke down and spent the money for a new carb, after fighting and tinkering with the existing carb... Best 65.00 I've spent in a while... Idles perfect, seems very smooth now. Hope to run it a little tonight and see how it runs in the real world. (Was raining last night so I was relegated to smoking up the garage.) Actually didn't smoke up the garage...

My only concern is the tach was still reading 76-7700 RPM WOT. I know these should run at around 7200 +-200. I remember Lakeside stating there is a 1000 range. Does anyone know if that's ok on 4-mix units too? Should I be concerned running this thing at 76-7700?