Stihl BR 600-Z Blower: service help please!

[pdqdl]

My blower keeps having valve problems.

First time: ZERO compression; the rocker arm for the valve popped off its position, and it was holding the valve open.

2nd time (now!): monster compression, we can't start it because it can't hardly be turned over.

I believe the valve adjusting nuts are creeping loose, and the valve timing is all wrong. Right now it feels like about .040-.050 clearance, and we would like to re-adjust.

Unfortunately, I don't know how. The gap is tiny, and nothing we have can measure the gap. Also, I have no idea what the proper valve lash is.

View attachment 177293


Any advice?

Does anybody know what Stihl has to say about keeping the valves from changing, and is there a history of this problem from other owners?

 

[blsnelling]

I just went through 6 of these. Four had broken exhaust valves. One had two bent pushrods. The problem is lack of maintenance. Those valves have to be a justed every 50 hours. I seriously doubt they're backing off. It is possible that your plastic camshaft lobe is worn. Adjusting them is simple. A single bolt holds on the valve cover. Then you simply turn the adjusting nut clockwise to reduce the clearance. Spec is .004".

 

[Trigger-Time]

My blower keeps having valve problems.

First time: ZERO compression; the rocker arm for the valve popped off its position, and it was holding the valve open.

2nd time (now!): monster compression, we can't start it because it can't hardly be turned over.

I believe the valve adjusting nuts are creeping loose, and the valve timing is all wrong. Right now it feels like about .040-.050 clearance, and we would like to re-adjust.

Unfortunately, I don't know how. The gap is tiny, and nothing we have can measure the gap. Also, I have no idea what the proper valve lash is.

View attachment 177293


Any advice?

Does anybody know what Stihl has to say about keeping the valves from changing, and is there a history of this problem from other owners?

Are you setting it with ignition at TDC?.........also with engine cold.

TT

 

[Motorsen]

Valve adjustment

As long as the corresponding valve is not actuated by the cam. You can measure and adjust. TDC at the compression/combustion stroke. Or TDC at exhaust stroke? At comp/combustion stroke yes. Exhaust stroke no. Almost all engines have valves adjusted cold. Allthough some japanesse manufactures specify a warm clearance too.

 

[pdqdl]

I CAN"T set the valve lash. The teeny tiny valve is shielded on both sides with tabs on the rocker arm that keep a normal feeler guage from being inserted.

It would take a feeler gauge about 1/8" wide to be able to insert it.

Even if I had the right tool, I still wouldn't know what setting to adjust it to, either. Well...until blsnelling told me 4 thousandths!

 

[Trigger-Time]

I CAN"T set the valve lash. The teeny tiny valve is shielded on both sides with tabs on the rocker arm that keep a normal feeler guage from being inserted.

It would take a feeler gauge about 1/8" wide to be able to insert it.

Even if I had the right too, I still wouldn't know what setting to adjust it to, either.

Both valves are set at 0.004

Stihl sells a valve adjusting kit, it comes with a feeler gauge made
just for the job.

TT

 

[Motorsen]

0.004???

Brad you mean 0.04 not 0.004??? If 0.004 is correct it damn tight. Or it´s just me thats old fashioned. Like the first time i saw a caterpillar piston for a new generation industrial engine. I thought the guys want pullig a joke. It looked like a racing piston. Almost no skirt!

 

[Aaron441]

No they're right, its .004. 4 thousandths.

 

[blsnelling]

Both valves are set at 0.004

Stihl sells a valve adjusting kit, it comes with a feeler gauge made
just for the job.

TT

I made my own from a standard feeler guage. When I bought seal and gasket kits for the two I just put new valves in, they came with the feeler guages. Do I've got three of them now.

 

[honda12967]

Check the valve seats when your in there, We had tons of valve seats move on the br600. Stihl didnt believe us when we warrentied them, they sent a rep down and he looked at the valve seats and it was clear that they moved. Its looking like it is getting to be a big problem with valves on the br600s. Just offering some advice, i see these everyday at our store.

Chris

 

[pdqdl]

Thanks guys! We will be sure to check the valve seats, too.


...We might not have checked that one!

 

[FATGUY]

I just adjusted the valve clearance on my neighbors br600. Is it normal to hear the valve train "tick"? If I back off the nuts the ticking goes away, when I re-tighten to spec., they click. Anyone?

 

[FATGUY]

the other thing I forgot to mention is the exhaust valve seems to stay ever so slightly open while the intake is opening/closing. It appears after the intake closes completely, the exhaust valve then closes completely. Is this a faulty cam or some sort of complicated compression release system I don't understand?

 

[lone wolf]

I CAN"T set the valve lash. The teeny tiny valve is shielded on both sides with tabs on the rocker arm that keep a normal feeler guage from being inserted.

It would take a feeler gauge about 1/8" wide to be able to insert it.

Even if I had the right tool, I still wouldn't know what setting to adjust it to, either. Well...until blsnelling told me 4 thousandths!

Take a pair of scissors and cut the feeler gauge more narrow no big deal as the dealer would have you believe.

 

[Roll Tide]

Part number 4282 007 1001. Includes a feeler gauge, new gasket and copper washer. If Im not mistaken they are no more then about $3. Comes with everything you need to set your valves.

 

[lone wolf]

I just went through 6 of these. Four had broken exhaust valves. One had two bent pushrods. The problem is lack of maintenance. Those valves have to be a justed every 50 hours. I seriously doubt they're backing off. It is possible that your plastic camshaft lobe is worn. Adjusting them is simple. A single bolt holds on the valve cover. Then you simply turn the adjusting nut clockwise to reduce the clearance. Spec is .004".

Plastic cam lobe huh?

 

[FATGUY]

they're a light powerful unit but it seems they've had their fair share of issues. From what I understand, periodic maintenance along with running good fuel will go a long way...

 

[Roll Tide]

they're a light powerful unit but it seems they've had their fair share of issues. From what I understand, periodic maintenance along with running good fuel will go a long way...

Running Ultra oil and good quality fuel, also adjusting valves after every season is good practice.The biggest problems with the 4 mixs is the carbon build up sticking the valves and valves not being adjusted. Other than that they are great units.IMO

 

[FATGUY]

Running Ultra oil and good quality fuel, also adjusting valves after every season is good practice.The biggest problems with the 4 mixs is the carbon build up sticking the valves and valves not being adjusted. Other than that they are great units.IMO

did you happen to read the 2 questions I had on page one( ticking and an extra movement of the exhaust valve)? I'd like to get the blower back to my neighbor as soon as I can, but I certainly don't want to give it back to him if it needs to be repaired.

 

[Roll Tide]

did you happen to read the 2 questions I had on page one( ticking and an extra movement of the exhaust valve)? I'd like to get the blower back to my neighbor as soon as I can, but I certainly don't want to give it back to him if it needs to be repaired.

The ticking is not normal, could be excess carbon build up. They make a decarbonizer, you remove the plug with the piston at TDC and fill it to the top of the spark plug hole. Let it sit for 24 hours, turn it upside down to drain it out. When you first start it, it will not wanna idle and you will get black smoke then it clears up. That would be my first guess.