Stihl BR700 leaf blower oil

[e30m3pilot]

Good Morning! I am curious if anyone has a Stihl leaf blower (BR700 or close) and has experience with what oils and mix ratios work best. As a former engine design and testing engineer I always stick to the books but I just so happen to some OEM recommendations are cost based and pass internal tests vs. are actually better long term. That stated and what sparked this thread is I have two BR700's right now, right next to each other creating a very simple A-B compassion test. His is significantly smoother running than mine. He doesn't know the oil or mix ratio yet as he just got it but I think that could make the difference. Also, both have new ethanol free gas.


Has anyone played with these and found a difference in operation with oil types or mix ratios? I wold never go leaner on the mix but maybe a 40:1 vs 50:1 smooths things out? heck I might just need a new plug too...

Thoughts?

 

[irad]

I have an old br700, probably over ten years. I use a 32:1 ratio. I use this ratio in all my 2 cycle equipment.

 

[JHZR2]

How do you know that its the oil versus something else?

Id start something simple, maybe a plug swap. Then fuel swap.

Id have my doubts that the difference in dilution makes a difference in smoothness.

 

[CT8]

I use 32 to 1 on all my 2 stroke ope. The exhaust ports are clean. They run for several hours continuously when wacking 3 acres of hill side for fire safety.clearance. Is the carb adjustable on that model?

 

[e30m3pilot]

Originally Posted by JHZR2
How do you know that its the oil versus something else?

Id start something simple, maybe a plug swap. Then fuel swap.

Id have my doubts that the difference in dilution makes a difference in smoothness.


So do I but both are roughly the same hours and in very good condition. Will do a plug swap to knock that off the list but there is no indication of poor running/misfires etc. Fuel is a week old both ethanol free... It's one of those things where you have to see and feel it and you do that .."huh...why is that so different" head scratching thing...

 

[ragtoplvr]

Since an open loop carburetor meters the same amount of fuel for E0 (Pure) and Ethanol laced fuels, the engine runs a little leaner on ethanol. Since right now ethanol cost more than gasoline, not all E10 is really E10

A carb adjustment is always good. Special screws, Ebay has the screwdrivers you need.

I use only E0 fuels on all outdoor power equipment. I have not had to readjust anything.

Rod

 

[e30m3pilot]

Thanks Rod! I will clean up the other unknowns (plugs, ratio and oil type) and finally compare the settings as well. I which I has some good instrumentation so I could log data before and after....

 

[thastinger]

I have a BR600. I run the VP 2 stroke oil at 40:1 in non ethanol fuel, which I get from my local marina.

These blowers have valves, might want to adjust them if you never have.

 

[BAJA_05]

For my Stihl Blower and Stihl Weed Wacker -- I run Exxon 89 octane with Stihl 2 stroke oil or Husqvarna low smoke 2 stroke mixed at 50:1 or 2.6 ounces to 1 gallon of gas. Both machines are 7 years old and zero issues.

 

[e30m3pilot]

Good stuff thanks all! Yeah I have never adjusted or done anything but a new plug every few years. Maybe time to look into that. The darn think just works and runs so well I've never had to do anything! Great product.

 

[ironman_gq]

50:1 stihl ultra in all my 2-stroke OPE with 91 non-ethanol fuel. In the last 10 years I've changed spark plugs in my chainsaws maybe once or twice and the mufflers and ports are clean. Only issue I've ever had with running was one of my saws needing new crank seals, changed those out and readjusted the carb and it's back to like new. That particular saw is 20 years old and was rebuilt with a new top end and ported about 10 years ago, insides looked the same as they did when I rebuilt it and it's still blowing 185psi compression.

In my experience getting the carb tuned properly is going to have a much bigger effect on how an engine runs and the lifespan of the motor than the difference between 32:1 and 50:1 assuming you use a good premium oil and fresh fuel.

 

[Kawiguy454]

+1 the get carb adjust tool. air cooled 2-strokes are sensitive to temperature and work load. Get the oil mix you want then adjust the carb next time it does real work. Always err on rich side.

 

[Rand]

I use the best Jaso FD rated 2 cycle oils at 50:1 sometimes a little more maybe 45:1

 

[bmwpowere36m3]

BR600 bought new along with FS90R trimmer, purchase of Stihl synthetic oil double warranty, so first 6 gallons used it a 50:1. I occasionally ran Echo powerblend at 50:1 and now I run Amsoil Saber 80:1 exclusively.

 

[OIL_UDDER]

80:1 holy smokes! ...³

 

[e30m3pilot]

I'm def going to check valves and change plug. Need that tool now 🤔ðŸ§

 

[super20dan]

i have used stihl 600.s for many years. not supposed to use regular 2 cycle oil in these. synthetic only! it will gum up the valves if non synth is used. I have used amzoil at 80/1 and stihl ultra at 50/1 with great results.