OP
TractorLegend
Platinum Member
4 mix is a 2 cycle---maybe they should have called it 2 mix--lol
Stihl gas powered equipment--rev limit increase?
- Thread starter TractorLegend
- Start date
- Views: 16899
Propertymaint
Silver Member
I thought so, a little play on words for advertising purposes I guess. Did you have any luck adjusting the high speed mixture screw? That should wake it up a bit.
</font><font color="blue" class="small">( 4 mix is a 2 cycle---maybe they should have called it 2 mix--lol )</font>
Check this: Stihl 4-mix
My take is that the 4-mix is a 4-stroke engine (even has valves!!) that runs on pre-mix. This eliminates the need for separate lubrication.
Both the standard Stihl 2 stroke engines AND the 4-mix run on 50:1.
I own both, and the 4-mix is definately a 4 cycle. And that's the rest of the story. /forums/images/graemlins/wink.gif
Check this: Stihl 4-mix
My take is that the 4-mix is a 4-stroke engine (even has valves!!) that runs on pre-mix. This eliminates the need for separate lubrication.
Both the standard Stihl 2 stroke engines AND the 4-mix run on 50:1.
I own both, and the 4-mix is definately a 4 cycle. And that's the rest of the story. /forums/images/graemlins/wink.gif
OP
TractorLegend
Platinum Member
I haven't had the opportunity to hot rod my saws---I need to bring them back from my rec property yet. I think Im going to remove, clean, and port match the muffler inlet, and then check mixtures.
The brand new backpack blower BR 550 model, went back the same day I bought it---it starved for fuel at half tank. I could tip it and get it to respond---the pickup screen was fully submersed, so I suspect a pickup tube issue---I'll know tomorrow, dealer called too late for me to know whats up---I almost suspect they will say it worked great for them cause you'd have to run it a while really using it on slopes etc. I'll report tomorrow...
The brand new backpack blower BR 550 model, went back the same day I bought it---it starved for fuel at half tank. I could tip it and get it to respond---the pickup screen was fully submersed, so I suspect a pickup tube issue---I'll know tomorrow, dealer called too late for me to know whats up---I almost suspect they will say it worked great for them cause you'd have to run it a while really using it on slopes etc. I'll report tomorrow...
OP
TractorLegend
Platinum Member
My take is that the 4-mix is a 4-stroke engine (even has valves!!) that runs on pre-mix:
-----------------------------------------------------------------------
Well I'll be go to.... I think you are correct---I didn't even study what I bought this time, I just assumed since the oil and gas are mixed--it's a 2 cycle. And since it said Stihl, I said SOLD!
It starts easy, its quiet and all---but I'll see whats up with the starvation issue mine has before opining.
I thought it would blow with a bit harder force being the big boy model---thats why I was hoping for a couple hundred rpm top end increase after break in.
I havent used backpack blowers before to compare with to give a real opinion on force of blowing. Maybe they don't want sissies blowing over backward when hitting the throttle /forums/images/graemlins/shocked.gif
-----------------------------------------------------------------------
Well I'll be go to.... I think you are correct---I didn't even study what I bought this time, I just assumed since the oil and gas are mixed--it's a 2 cycle. And since it said Stihl, I said SOLD!
It starts easy, its quiet and all---but I'll see whats up with the starvation issue mine has before opining.
I thought it would blow with a bit harder force being the big boy model---thats why I was hoping for a couple hundred rpm top end increase after break in.
I havent used backpack blowers before to compare with to give a real opinion on force of blowing. Maybe they don't want sissies blowing over backward when hitting the throttle /forums/images/graemlins/shocked.gif
MessickFarmEqu
Super Member
If you read the landscape forums most everyone agress that the Stihl BR600 - only marginly larger is one of the top blowers available. I'm sure you'll be impressed once its running properly - they put that static discharge wire down the tubes for a good reason.
Propertymaint
Silver Member
Well I'll be daw-gone. I didn't see this info when I went to the Stihl site but your right - the combustion cycle runs on a four stroke principal. I never worked on one of these before but I heard they were coming out with 4-stroke trimmers etc the past couple of years - I think Honda is the other company. I always wondered how they would lubricate the engine while it was upsidedown. That was the beauty of the two stroke engine. For those who are unfamiliar with two and four stroke cycles try this site www.keveney.com. Nice job!
Thanks for the scoop on the BR550. I currently have a BR340 (2-stroke), and plan to upgrade to the BR600. Supposedly, there is a significant performance increase over the BR550 for only $70 more.
I bought a FS110 trimmer (4-mix)last year and have been thrilled with its performance. I love the starting ease, low end torque, and less noise. After using 2-stroke trimmers for years, I'm completely sold on the 4-Mix!
Good luck with that BR550. Maybe it does need tuning from your dealer.
I bought a FS110 trimmer (4-mix)last year and have been thrilled with its performance. I love the starting ease, low end torque, and less noise. After using 2-stroke trimmers for years, I'm completely sold on the 4-Mix!
Good luck with that BR550. Maybe it does need tuning from your dealer.
OP
TractorLegend
Platinum Member
I got the defective BR550 back today still defective---starving for gas or drawing a vacuum in the tank---they said they ran two tanks thru it with no issue---but I had it back and after running only 12-15 minutes it did the same thing, back it goes to their shop. Maybe they just let it idle...its BRAND NEW, so I'm not personally fixing it--it's someone elses prob.
The Stihl blower has poor fuel economy I think, and after this one gets the bugs worked out of the fuel starvation issue by my or another dealer, I will trade it to someone for labor on some home improvements and I will get a Red Max brand blower---likely a 7000 or 8000 series.
If I bought this at a home center (which Stihl doesn't do) I would have taken it back for a refund.
The Stihl blower has poor fuel economy I think, and after this one gets the bugs worked out of the fuel starvation issue by my or another dealer, I will trade it to someone for labor on some home improvements and I will get a Red Max brand blower---likely a 7000 or 8000 series.
If I bought this at a home center (which Stihl doesn't do) I would have taken it back for a refund.
OP
TractorLegend
Platinum Member
Heres the scoop on the fix for my brand new BR550 blower. It was starving for fuel when it would get to about 1/2 tank. The techs apparently couldn't get it to act up for them. The Stihl tech line told them to lenghthen the pickup tube and put a larger pick up filter in the tank, they had some reported issues of this. The dealer did the modification and it feels like it has more power to boot and not a hickup.
Likely Stihl will come out with a bulletin on these.
If you have one of these, you may want to do this just for the runability/ power improvement, even if its not dying out like mine was. Maybe they all starve a bit, but not to the extent of dying.
Likely Stihl will come out with a bulletin on these.
If you have one of these, you may want to do this just for the runability/ power improvement, even if its not dying out like mine was. Maybe they all starve a bit, but not to the extent of dying.
