I was wanting to tear into a few of my 4mixes and maybe clean the valve seats and faces. What tools will be needed and parts if any? Im mechanically inclined but needing to know if theres anything to be aware of from the ones with experience. I had a guy tell me one time to stretch the intake spring. Posted via Mobile Device
Do a search on here, lots of posts, (some with links) about them!
Stretch the intake spring? WTF is an intake spring? And why would ya wanna stretch it??
That stretch the spring talk better have some amazing reason but it sounds like hocum. Now, the only special tool that I didn't have is the feeler gauge, which was under $1 from Stihl, because it has a narrowed in tip. Adjusting the valves is simple enough. I haven't had any out fully, that means pulling the cover at the bottom of the crank case. Have fun!
Hmmmm, feeler gauge for under $1.00,...? Mine was on a card, plastic wrapped to a card, and I think it was over $5.00. I can't remember. Finding anything with the name Stihl on it for under $1.00 is rare. I realize the gauge isn't much -- but as you point out, the shape is necessary to reach the target.
But, under $1.00 ...?
I will be interested in other posts in this thread, and what tasks the OP does for his machine. So, subscribed.
I have the feeler gage and it was indeed under $1.00. I recently adjusted all of my 4 mix valves lately and it is very easy to do. Weed eater style heads are very easy to adjust. My BR600 Magnums are a bit harder to adjust because there is multiple covers that you have to take off that are hard to line up right when putting them back on. The only tools necessary is the star head wrench that came with all of Stihl products and then a metric wrench(I think it was a 8mm, forgot exactly) to adjust the valve. Pretty simple. Blower took 20-30 mins to do due to having trouble lining up the covers. Everything else took less than 10 mins. Hope everything goes well!
Hmmmm, feeler gauge for under $1.00,...? Mine was on a card, plastic wrapped to a card, and I think it was over $5.00. I can't remember. Finding anything with the name Stihl on it for under $1.00 is rare. I realize the gauge isn't much -- but as you point out, the shape is necessary to reach the target.
But, under $1.00 ...?
I will be interested in other posts in this thread, and what tasks the OP does for his machine. So, subscribed.
First off, what 4-Mix models are you wanting to tear into?
Why do you want to tear into them? Is there a specific problem with each one of them?
If it ain't broke, why fix it?
In my opinion, unless there is a specific problem you are having with ANY unit, only general maintenence would be expected which would include adjusting the valves on the Stihl 4-Mix units.
As with any post/thread/reply, there always seems to be a certain amount of BS sprinkled into the mix, which has been shown here also...
I would disregard any and all information from the person that told you to "stretch the intake spring"!
The "Valve Adjusting Kit" for the BR500,550 and 600 is part number 4282 007 1001. This kit includes the valve cover gasket, sealing washer on the valve cover screw and the feeler gauge. MSRP on this kit is $3.11!
The "Valve Adjusting Kit" for an FS90 is part number 4180 007 1005. This kit includes the valve cover gasket, sealing washer on the valve cover screw and the feeler gauge. MSRP on this kit is $3.60!
The feeler gauge (included in above kits) is the same for ALL Stihl 4-Mix units and is part number 4180 893 6400 and has a MSRP of $0.20!
You also have the option of using EDTA which you could get from your Stihl Dealer. It's sole purpose is to loosen, disolve carbon build up in engines. To use in the 4-Mix units, simply rotate crank shaft to get to the end of the exhaust/beginning of intake stroke (both valves will be slightly open), then fill the cylinder through spark plug hole with the EDTA and leave sit for for upto 24 hours. Then pour out remaining ETDA through spark plug hole, reinstall spark plug, check/adjust valves and then you are good to go!
I do have a complete set of cleaning pads in different "grits", styles and sizes for the 4-Mix units, but NEVER use them unless I am tearing the unit down anyway for another reason!
Jeff, thanks for chiming in here. I stand corrected. Your kit number for an FS90 is not the same as I posted above, but my purchase was several years ago. And, yes, it did not only have the feeler gauge, but also the two gaskets you noted. The larger one can be seen in the package.
As for price, I do remember the larger price paid at the time, but I bought other things at the time. I went back to my QuickBooks records, and found that I had not only the kit, but some other things. So, I was wrong about the price of the kit, but right about having paid more at the time because of buying more things. Thanks for clearing. I still do find the $0.20 interesting for any Stihl part, but will defer to your familiarity. Somehow $0.20 and Stihl don't go in the same sentence.
First off, what 4-Mix models are you wanting to tear into?
Why do you want to tear into them? Is there a specific problem with each one of them? Was wanting to tear into a fs 110. I found out about the bottle of decarbonizer today. Does it work 100% ? I used to build race engines for racing go karts. I just find stuff to keep me busy this time of year. I stay on top of my valve maintenance but have seen carbon on the face of the valves on a br 600.
If it ain't broke, why fix it?
In my opinion, unless there is a specific problem you are having with ANY unit, only general maintenence would be expected which would include adjusting the valves on the Stihl 4-Mix units.
As with any post/thread/reply, there always seems to be a certain amount of BS sprinkled into the mix, which has been shown here also...
I would disregard any and all information from the person that told you to "stretch the intake spring"!
The "Valve Adjusting Kit" for the BR500,550 and 600 is part number 4282 007 1001. This kit includes the valve cover gasket, sealing washer on the valve cover screw and the feeler gauge. MSRP on this kit is $3.11!
The "Valve Adjusting Kit" for an FS90 is part number 4180 007 1005. This kit includes the valve cover gasket, sealing washer on the valve cover screw and the feeler gauge. MSRP on this kit is $3.60!
The feeler gauge (included in above kits) is the same for ALL Stihl 4-Mix units and is part number 4180 893 6400 and has a MSRP of $0.20!
You also have the option of using EDTA which you could get from your Stihl Dealer. It's sole purpose is to loosen, disolve carbon build up in engines. To use in the 4-Mix units, simply rotate crank shaft to get to the end of the exhaust/beginning of intake stroke (both valves will be slightly open), then fill the cylinder through spark plug hole with the EDTA and leave sit for for upto 24 hours. Then pour out remaining ETDA through spark plug hole, reinstall spark plug, check/adjust valves and then you are good to go!
I do have a complete set of cleaning pads in different "grits", styles and sizes for the 4-Mix units, but NEVER use them unless I am tearing the unit down anyway for another reason!
The 4-Mix blowers are the "4282" series units, so the kit you have shown in your picture is for a BR500,550 or 600 only.
The 4-Mix shafted products all use the "4180" series kits.
On a side note, I would recommend using 2 feeler gauges stacked on the exhaust valve only on the BR product. Not needed on the hand held units.
I have been amazed also at the retail price of some of the parts for a Stihl unit. You would be surprised at how many spare parts that are under $1.00!
I agree however on the flip side that there are some items that are priced sky high!
I worked at a stihl dealer ship for about a year as a mechanic
first the guy that says stretch out your valve spring should never touch a machine
stihl recommends using one feeler gauge on the intake and 2 on the exhaust valve
I would not recommend taking apart unit unit until it dies to learn the machine . If you run synthetic mix oil it keeps the carbon build up to a minimum.
usually the main service things to do to a 4 mix are a valve adjust ( the best indicator is when it gets hard to turn the machine over from extra compression ) change the spark plug , fuel filter ,air filter and make sure the spark screen is not plugged (if it is plugged use a propane torch the heat till red and use compressed air to blow out the charred carbon out )
if you do decide to take apart the motor the basic tools are the 2 torx bits I forget the sizes and a 8 mm socket for the valve adjust and a tube of ultra black silicon or ( dirco is what stihl dealers use )
I'm not sure why the double on exhaust, I saw it on Youtube... :laugh:
Actually, the real reason is that there was an issue with excessive carbon build up on the exhaust valve years ago. Then they changed the exhaust valve to a "bi-metal" valve. This helped with the excessive carbon build up for the most part. Even with the changes, there is still a unit from time to time with carbon deposit issues. However, today it is mostly due to their fuel or running with a broken tube and not getting the RPM's/engine temp up to burn off the deposits.
The thought process or reason to double up on the exhaust valve on the BR units is to allow a longer seat time to help keep the valve cooler. Even though it is only nano-seconds that it is closed longer, it has made a big difference, combined with other changes to help minimize carbon deposits forming on the valve face and seat. There has been no issue with the trade off of doing so which will cause a slightly lower lift height to the valve when open!
Abrasive pads to remove carbon deposits from valves and seats on the 4-Mix units as well as a pad I use on any and all engines with silicone/RTV sealant...
I'm not sure why the double on exhaust, I saw it on Youtube... :laugh:
Actually, the real reason is that there was an issue with excessive carbon build up on the exhaust valve years ago. Then they changed the exhaust valve to a "bi-metal" valve. This helped with the excessive carbon build up for the most part. Even with the changes, there is still a unit from time to time with carbon deposit issues. However, today it is mostly due to their fuel or running with a broken tube and not getting the RPM's/engine temp up to burn off the deposits.
The thought process or reason to double up on the exhaust valve on the BR units is to allow a longer seat time to help keep the valve cooler. Even though it is only nano-seconds that it is closed longer, it has made a big difference, combined with other changes to help minimize carbon deposits forming on the valve face and seat. There has been no issue with the trade off of doing so which will cause a slightly lower lift height to the valve when open!
Good to know on the valve adj!
Yeah, it's been awhile since I worked for a Stihl dealer, so have not heard much in the way of tech info. The last 4-mix info I got concerned the valve change,( Sept. 09 or so) but no mention of the clearance increase. Thanks again for sharin'.
Good to know on the valve adj!
Yeah, it's been awhile since I worked for a Stihl dealer, so have not heard much in the way of tech info. The last 4-mix info I got concerned the valve change,( Sept. 09 or so) but no mention of the clearance increase. Thanks again for sharin'.
It is not "published" to double up on the exhaust valve clearance in the Service Manual.
But in some tech info it states the following:
The adjustment setting for all Stihl 4-Mix engines is 0.1 mm (.004) when engine is cold.
This is the minimum gap to use for setting valves, but a gap as wide as 0.3 mm (.012) is acceptable.
It has only been an issue on the BR's as opposed to shafted product, and only on the exhaust valve.
I'm not sure why the double on exhaust, I saw it on Youtube... :laugh:
Actually, the real reason is that there was an issue with excessive carbon build up on the exhaust valve years ago. Then they changed the exhaust valve to a "bi-metal" valve. This helped with the excessive carbon build up for the most part. Even with the changes, there is still a unit from time to time with carbon deposit issues. However, today it is mostly due to their fuel or running with a broken tube and not getting the RPM's/engine temp up to burn off the deposits.
The thought process or reason to double up on the exhaust valve on the BR units is to allow a longer seat time to help keep the valve cooler. Even though it is only nano-seconds that it is closed longer, it has made a big difference, combined with other changes to help minimize carbon deposits forming on the valve face and seat. There has been no issue with the trade off of doing so which will cause a slightly lower lift height to the valve when open!
This is not just for Stihl or 4 mix. When adjusting the valves on my car, the procedure is to tighten the intake to minimum spec and adjust the exhaust to maximum spec. This is SOP for all 4 stroke engines. Posted via Mobile Device
read this last night, interesting on the adjustment numbers. gotta remember this and re-read, thanks. with my machine getting up in the yrs and countless hrs. it's been a great machine btw, seams it never gets a rest, in use all 4 seasons here. anyway me being not the most experienced in working on these machines and learning as i go. do see at some point me having to possibly going and replace some internal engine parts (for lack of a better way of putting it, tearing it down). so atm trying to learn what i could without them but gotta ask, without any diagrams or something to reference, is they a way to get such. is there a way to get these? can i get these from a dealer, are they for sale?
This is not just for Stihl or 4 mix. When adjusting the valves on my car, the procedure is to tighten the intake to minimum spec and adjust the exhaust to maximum spec. This is SOP for all 4 stroke engines. Posted via Mobile Device
Just to keep on track here, this discussion is not about automobile engines or their specs. This discussion IS on Stihl 4-Mix engines and the specs. that pertain to them.
In my opinion, the SOP is to follow the manufacturers specs. unless other wise noted, such as in this case, which is to double the exhaust valve on the BR engines only!
read this last night, interesting on the adjustment numbers. gotta remember this and re-read, thanks. with my machine getting up in the yrs and countless hrs. it's been a great machine btw, seams it never gets a rest, in use all 4 seasons here. anyway me being not the most experienced in working on these machines and learning as i go. do see at some point me having to possibly going and replace some internal engine parts (for lack of a better way of putting it, tearing it down). so atm trying to learn what i could without them but gotta ask, without any diagrams or something to reference, is they a way to get such. is there a way to get these? can i get these from a dealer, are they for sale?
thanks jeff much appreciated. hope the op doesn't mind posting on this, was thinking of starting a new thread but for now will keep short, hopefully could add to it something of use. where i at is used the bp blower (only own one) the other day after some light snow for clean up and at one point had the machine die out on me. fuel issues, idk but do want to go in and give it a going over at some point. like mentioned before it's been used constant since 07 and not sure what the norm is on the compression or really remember what it was like new but it seams when the machine warms up and i restart there is hardly any at all. recheck of the valves seams in orders later this wk but have been thinking with its age and use of looking into the de-carbonizer procedure mention earlier. never really explored getting into the machine past getting to the point of adjusting the valves getting it back together but now curious about how to go about it, see what the internal looks like (cam etc.).
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