Stihl New 4 stroke using 2 stroke fuel mix

[FNFAL308]

Originally Posted By: 660mag
Originally Posted By: Blaze
How often do you have to adjust the valves and how difficult is the job for a typical user?

Very easy.
1. order the special feeler gauge #4180-893-6400 and a new valve cover gasket #4180-029 0500
2. remove the three t27s that hold the orange engine cover in place.
2. remove the sparkplug, and the t27 screw that holds the valve cover on.
3. set the piston to tdc of the compression stroke.(both rockers will be a little loose at this point.
4. using an 8mm wrench tighten the self locking nuts atop the rocker arms while measuring the lash with your new feeler gauge until the lach is corrected.
5. when done pull the rope a few times and recheck the lash, adjust as needed.
6.replace the vc gasket, and vc cover. new plug in.
7.Check the throttle cable at this point to be sure it's opening the carb all the way, adj if needed.
8.install the orange cover and yer off.

The decompression lobe on the cam will now also be back in spec and the rope should pull effortlessly.

The decarb service should be done at this time as well.

Oh yea it should be done about every 125hrs, but will all depend on the way the tool is being used.
clogged air filter, bad adjustment on the throttle cable, poor fuel, poor oil, or oil mix, low rpm use, trim line too long(leading to low rmp use), or short tripping(if you will) will all lead to a shorter interval.

If nothing is ever done wrong they can go much longer than 125hrs.


Quote:
3. set the piston to tdc of the compression stroke.(both rockers will be a little loose at this point.


Also remember to align the "ARROW" on the Flywheel with the leg of the coil...
In a home owner use situation I doubt the VC gasket will need replaced when adj the valves unless a ham fisted owner messes it up..

 

[car54]

hmm, I'm gonna go buy some of this fuel. My huge saws almost never get used and they both need a carb rebuild. Bought them before hurricane Isabel just because, ended up paying for themselves 1000x in a two month period, and now just get occasional use. No matter what the cost, if it keeps the carbs and equipment in top shape, it's worth it.

I had been buying ethanol free 91 octane from a marina, but it's almost $7 per gallon now and a 1hr boat ride from my house, so stihl fuel is almost cheaper and certainly more convenient.

 

[Steve S]

Originally Posted By: Chris142
Originally Posted By: Hallmark
I'll pass...thanks!
He's probly thinking like I am. Whats the point of a 4 stroke if your still mixing gas and oil? The reason for looking into a 4 stroke is to get away from mixing gas and oil.

I'm looking into the Propane fueled stuff but it's hard to find here. With Propane you don't have to worry about fuel gumming up the carb.
In the 23.5 years I was able to work on propane forklifts and a few propane vehicles there are propane carb type problems . There never is any free lunch.

 

[boraticus]

Originally Posted By: 660mag
Originally Posted By: Blaze
How often do you have to adjust the valves and how difficult is the job for a typical user?

Very easy.
1. order the special feeler gauge #4180-893-6400 and a new valve cover gasket #4180-029 0500
2. remove the three t27s that hold the orange engine cover in place.
2. remove the sparkplug, and the t27 screw that holds the valve cover on.
3. set the piston to tdc of the compression stroke.(both rockers will be a little loose at this point.
4. using an 8mm wrench tighten the self locking nuts atop the rocker arms while measuring the lash with your new feeler gauge until the lach is corrected.
5. when done pull the rope a few times and recheck the lash, adjust as needed.
6.replace the vc gasket, and vc cover. new plug in.
7.Check the throttle cable at this point to be sure it's opening the carb all the way, adj if needed.
8.install the orange cover and yer off.

The decompression lobe on the cam will now also be back in spec and the rope should pull effortlessly.

The decarb service should be done at this time as well.

Oh yea it should be done about every 125hrs, but will all depend on the way the tool is being used.
clogged air filter, bad adjustment on the throttle cable, poor fuel, poor oil, or oil mix, low rpm use, trim line too long(leading to low rmp use), or short tripping(if you will) will all lead to a shorter interval.

If nothing is ever done wrong they can go much longer than 125hrs.



Ahhhh, yeah.... that sounds a lot easier than adjusting the valves on a two stroke!

Call me old school but, as far as I can see, there is NO advantage to any engine that will require more maintenance and/or expense to do the same job as one with a simpler, efficient and reliable design. Basic logic.

From what I've read so far, it would appear that in their endeavors to produce technically complicated engines, manufacturers are making efforts to boost the earnings for the dealership's service departments. I'm not surprised to see dealers and servicemen ardently endorsing them. Money in the bank.

If these engines are so good, why doesn't Stihl put them in their saws? I'd say the reason is that they'd lose their saw market overnight.

Why mess with a good thing?

I'll stay with my tried a true two cycle engines. Thank you.

 

[Jeepster_nut]

Drift~~~~~~I have had a renewed interest in 2 stroke OPE. I would like to find a lawnboy walk behind mower. Any good ones or bad ones?

 

[660mag]

Originally Posted By: boraticus
Originally Posted By: 660mag
Originally Posted By: Blaze
How often do you have to adjust the valves and how difficult is the job for a typical user?

Very easy.
1. order the special feeler gauge #4180-893-6400 and a new valve cover gasket #4180-029 0500
2. remove the three t27s that hold the orange engine cover in place.
2. remove the sparkplug, and the t27 screw that holds the valve cover on.
3. set the piston to tdc of the compression stroke.(both rockers will be a little loose at this point.
4. using an 8mm wrench tighten the self locking nuts atop the rocker arms while measuring the lash with your new feeler gauge until the lach is corrected.
5. when done pull the rope a few times and recheck the lash, adjust as needed.
6.replace the vc gasket, and vc cover. new plug in.
7.Check the throttle cable at this point to be sure it's opening the carb all the way, adj if needed.
8.install the orange cover and yer off.

The decompression lobe on the cam will now also be back in spec and the rope should pull effortlessly.

The decarb service should be done at this time as well.

Oh yea it should be done about every 125hrs, but will all depend on the way the tool is being used.
clogged air filter, bad adjustment on the throttle cable, poor fuel, poor oil, or oil mix, low rpm use, trim line too long(leading to low rmp use), or short tripping(if you will) will all lead to a shorter interval.

If nothing is ever done wrong they can go much longer than 125hrs.



Ahhhh, yeah.... that sounds a lot easier than adjusting the valves on a two stroke!

Call me old school but, as far as I can see, there is NO advantage to any engine that will require more maintenance and/or expense to do the same job as one with a simpler, efficient and reliable design. Basic logic.

From what I've read so far, it would appear that in their endeavors to produce technically complicated engines, manufacturers are making efforts to boost the earnings for the dealership's service departments. I'm not surprised to see dealers and servicemen ardently endorsing them. Money in the bank.

If these engines are so good, why doesn't Stihl put them in their saws? I'd say the reason is that they'd lose their saw market overnight.

Why mess with a good thing?

I'll stay with my tried a true two cycle engines. Thank you.

Yes two strokes require less maintenance, but it's all a trade off.
Oil/fuel bills are on joke to commercial co. No not the guy down the road that has 150 lawns to cut weekly, but a real commercial co.(750+) Saving 30% on fuel for your fleet of trimmers edgers and blowers will more than pay for the equipment itself if you can make it run for three years.
Fact. Stihl made these changes to adhere to local emissions laws. It's not debatable.
Im sure there margins were higher with two strokes.
Labor rates have only raised along with inflation in my state, and when the fs80 was still being sold it was the same pirce as the fs90.

You take an fs80 and I'll take an fs90(same price), each of us with a gallon of fuel, and watch me kill twice as many acres of plants, easer, and with less noise.(time is money)
The fuel savings more than pay for the tiny bit of extra labor, but cutting the job time in half makes it a no brainr.

The reason Stihl has not yet put a 4mix in a saw is because there fleet currently meets emissions, but when it does not they will start transitioning more of there product line to more efficient designs I assure you. Take a look at there ms211 chain saw, it's strato charged, and the ms441C-M has an electric controlled carb.
The enforcement of environmental protection policies are usually two fold with some of the benefit going to the end user. The ms441cm can ber run at sea level hot one day, and altitude cold the next with not one adjustment made to the carb.

 

[boraticus]

Originally Posted By: Jeepster_nut
Drift~~~~~~I have had a renewed interest in 2 stroke OPE. I would like to find a lawnboy walk behind mower. Any good ones or bad ones?


I own four old LB machines. Two with the D-400 series engine (points ignition), one with a D-600 engine (CD module ignition) and one with an F engine (CD module ignition).

The D-400 and D-600 engined machines are running fine. The F series engine ran for a while then it's 3rd CD module failed....

As much as I like CD modules, the Lawn Boy mowers with them have a dismal record of failure. My D-600 engine with the CD module is running great (for now), but who knows how long that will last. The other two machines a '65 and a '70 with point ignition are running as good as new. The problem nowadays is trying to find functional CD modules for these old mowers that will last and for a reasonable price. I bought two used ones and both failed. I'll probably shell out the $50.00 or $60.00 to buy an new one on ebay which is ironic considering I bought three of the mowers for $40.00.

Personally, I'd stay with something that has points ignition. Old technology but in a lawn mower, that's more than good enough.

 

[FNFAL308]

Originally Posted By: boraticus
Originally Posted By: 660mag
Originally Posted By: Blaze
How often do you have to adjust the valves and how difficult is the job for a typical user?

Very easy.
1. order the special feeler gauge #4180-893-6400 and a new valve cover gasket #4180-029 0500
2. remove the three t27s that hold the orange engine cover in place.
2. remove the sparkplug, and the t27 screw that holds the valve cover on.
3. set the piston to tdc of the compression stroke.(both rockers will be a little loose at this point.
4. using an 8mm wrench tighten the self locking nuts atop the rocker arms while measuring the lash with your new feeler gauge until the lach is corrected.
5. when done pull the rope a few times and recheck the lash, adjust as needed.
6.replace the vc gasket, and vc cover. new plug in.
7.Check the throttle cable at this point to be sure it's opening the carb all the way, adj if needed.
8.install the orange cover and yer off.

The decompression lobe on the cam will now also be back in spec and the rope should pull effortlessly.

The decarb service should be done at this time as well.

Oh yea it should be done about every 125hrs, but will all depend on the way the tool is being used.
clogged air filter, bad adjustment on the throttle cable, poor fuel, poor oil, or oil mix, low rpm use, trim line too long(leading to low rmp use), or short tripping(if you will) will all lead to a shorter interval.

If nothing is ever done wrong they can go much longer than 125hrs.



Ahhhh, yeah.... that sounds a lot easier than adjusting the valves on a two stroke!

Call me old school but, as far as I can see, there is NO advantage to any engine that will require more maintenance and/or expense to do the same job as one with a simpler, efficient and reliable design. Basic logic.

From what I've read so far, it would appear that in their endeavors to produce technically complicated engines, manufacturers are making efforts to boost the earnings for the dealership's service departments. I'm not surprised to see dealers and servicemen ardently endorsing them. Money in the bank.

If these engines are so good, why doesn't Stihl put them in their saws? I'd say the reason is that they'd lose their saw market overnight.

Why mess with a good thing?

I'll stay with my tried a true two cycle engines. Thank you.


It's pretty obvious you miss the advantages so I won't waste a bunch of time trying to explain them to you.. They have been very well documented already by another poster/s but it appears you didn't read that part??

I will however say that your perspective is way off.. I've worked on thousands of pcs of handheld equipment and will say without reservation these are some of the best handheld engines I've worked on.

I don't base my opinions on earnings, I own no STIHL stock and quite honestly I take offense in your implication that my comments and endorsements are somehow income driven. Your comments are way out of line and not only unfounded but quite simply untrue.. My thoughts, opinions, endorsements or whatever you choose to call them are based on nothing but years of experience and actual usage of the products I service.

Truth be told I make "WAY" more $$ on 2-Stroke repairs then I do on the 4-Mix stuff, so BY ALL MEANS "PLEASE" Keep on buying them. These engines are so good that most of the repairs I do are caused by abuse and neglect.. 2-Stroke engines have "issues" of their own and to assume any different shows your ignorance..

STIHL is head and shoulders above other companies in this industry and their application of significant R&D shows in their product line. I suspect there is a reason these engines are not in SAWS (may change at anytime?) but I seriously doubt you have insight enough to know why STIHL does anything they do?

BTW, (because I'm kinda interested) what brand 2-Stroke equipment do you own? What "types" of 2-Stroke equipment do you own? And lastly what's your application IE: Homeowner, or Commercial user?

 

[Steve S]

So the motor doesn't blow gas out of the exhaust port = less HC?

 

[FNFAL308]

That's part of it and your right 2-stroke engines are not very efficient as they "DO" send unburnt fuel out the exhaust.. That is but one of the drawbacks of 2-strokes, if you saw how many Spark Arrestor screens I clean a year you would be impressed I'm sure.

Here is a link that touches on a couple features:
http://www.stihl.com/isapi/default.asp?c...mix/default.htm
There is something in particular I would like to post up here and hope that I can find it? Will be sure to do so if I'm able..

Here is ONE I was looking for:
http://www.youtube.com/watch?v=yN5BWxXo1cc

 

[engineerscott]

Originally Posted By: boraticus



Personally, I'd stay with something that has points ignition. Old technology but in a lawn mower, that's more than good enough.


Points ignition??? You've got to be kidding. While there were issues with solid state ignition systems when they were introduced, oh 30 odd years ago, they are quite reliable now, and maintenance free. More reliable than mechanical points systems that suffer from wear and contact degradation. Electronic ignition systems are the reason you can walk up to the average piece of outdoor power equipment and expect it to crank on the 1st or 2nd pull without having to adjust the points every season (or even more frequently in many cases). Solid state ignition systems are a huge advancement in engines of all types.

 

[660mag]

He's recommending points are more reliable than solid because that's just how bad Lawnboy coils actually are. Totaled two Lawnboys today with failed coils.

 

[boraticus]

Originally Posted By: engineerscott
Originally Posted By: boraticus



Personally, I'd stay with something that has points ignition. Old technology but in a lawn mower, that's more than good enough.


Points ignition??? You've got to be kidding. While there were issues with solid state ignition systems when they were introduced, oh 30 odd years ago, they are quite reliable now, and maintenance free. More reliable than mechanical points systems that suffer from wear and contact degradation. Electronic ignition systems are the reason you can walk up to the average piece of outdoor power equipment and expect it to crank on the 1st or 2nd pull without having to adjust the points every season (or even more frequently in many cases). Solid state ignition systems are a huge advancement in engines of all types.


It would appear that in your enthusiasm and eagerness to bash "points" systems, you failed to observe that the discussion was about old Lawn Boy lawnmowers. Many of which are much older than the advent of CD modules. My preference to "points" ignition is for these machines only because their CD modules are famous for rate of failure.

I also own a few vintage Yamaha RD two stroke motorcycles that originally came with points ignition. The two machines that I have restored/modified no longer have points ignition. I have replaced them with state of the art programmable digital ignition systems. Why? Because these RDs will run to 11,000 rpm vs. 3200 rpm in a lawnmower. Things can go sideways in a hurry at 11K rpm. Not so much at 3200 rpm.

In a low revving machine such as a lawnmower, points ignition will work more than sufficiently and maintenance of same will be minimal. I doubt that in a lawnmower that's operated annually under normal conditions will require any points maintenance for years on end. The '65 I own is still running original parts. All I had to do to it was clean and adjust the points. As far as I'm concerned, points are simple, reliable and durable in any low speed OPE application.

 

[660mag]

Bet you a dollar I can adjust the valves on a 4mix faster then you can points on a lawnboy.
I'm thinking about 120sec is all it takes.

 

[FNFAL308]

Originally Posted By: 660mag
Bet you a dollar I can adjust the valves on a 4mix faster then you can points on a lawnboy.
I'm thinking about 120sec is all it takes.


WORD...

I didn't want to mention my best clocked times (easily under 120 sec) for fear it would spawn more comments and insinuation that we are STIHL Mouth pieces preying on the masses..

As to L/B Mowers..
LOL!! If I NEVER have to work on another POS L/B 2-Stroke mower I'd be thrilled..

 

[boraticus]

Originally Posted By: 660mag
He's recommending points are more reliable than solid because that's just how bad Lawnboy coils actually are. Totaled two Lawnboys today with failed coils.


Not failed coils. It's failed CD modules. There is a significant difference. Coils are used with points ignition and on the Lawn Boys, coils are fine. It's the "newer" CD modules that c-rap out on an all too frequent basis. Despite the bad CDs on the LB machines, they are without a doubt, fantastic mowers and I certainly wouldn't be trashing them simply for a bad CD. Lawn Boy is one of the best American OPE products ever produced.

Simple, light, strong, reliable and enduring. Anyone badmouthing Lawn Boys obviously has no understanding of the history of the product nor appreciation of the fact that there many thousands of them well over 40 years old still in active use. I doubt that there is much being made today that will stand the same testament of time.

 

[Steve S]

I hired one of the neighbor kids to weed wack one of the rental properties I own . For two days he used my Husky 325. Saturday he purchaced!!!! a Sthil 4 mix weed wacker and today I watched him use it ,sounds good and he said it was not as peaky powerwise like the Husky and used the 2 stroke vs 4 stroke dirtbike power feel as a comparison..

 

[660mag]

My only complaint about the 4mix is the usable power band is a little narrow for fine art like trimming. But the throttle plate type carb is after all made to run at wot. It would be interesting to test a barrel type throttle like the Walbro on a Honda 4stroke on one of these. The 4mix is a little jumpy for some homeowners.

 

[MBDiagMan]

Well I did something out of character yesterday. My Stihl Dealer is a one man operation and an Elite Dealer. I have dealt with him for several years and you won't find a better, more trustworthy small business ANYWHERE!

So, since I trusted him, after going in for a new, CHEAP line trimmer, when I started asking questions about adding a pole saw to it later, he started telling me about the FS 90 R which is the least expen$ive pro machine that can accept a pole saw.

When he said it was a four stroke, I thought he was pulling my leg. After some demonstration and him saying that it had been out since 2001 IIRC, I laid down the $319 plus tax.

I went straight home and started eating up some really tall, wet, heavy Rye grass. My old trimmer was a 1.2 HP 2 stroke Red Max that I always thought was powerful. This machine was like comparing a 6 foot shredder on a 65 horse tractor to an underpowered 19 inch lawnmower.

The torque of the four stroke is amazing. The cutter head does not wrap long cuttings around to jam it up as did the Red Max.

THEN, this morning I started googling about it and came across this thread. It started worrying me at first, but between some of the pro Stihl guru's posts and my trust for my dealer, I think I made a great decision.

I will be using high octane gasoline and the silver bottle premium Stihl oil.

Thanks for all the time spent posting in this thread. EXTREMELY informative.

 

[Kruse]

Is this 4-stroke model heavier than a 2-stroke?