Good morning all.

Over the years I have seen several of these threads here and ignored them because they weren't relevant to me. Now, I am going to buy one of these machines and I cannot make up my mind which one I want.  I am looking at the KM 91 R and the KM 94 R and the reviews seem mixed on the 4 mix and long term starting issues but, I like the extra power and fuel capacity. I haven't found many people with bad things to say about the KM 94 and I am leaning in that direction. Does anyone that own one these and have an opinion?

GD always has the answer.

Thank you

I haven't had any issues with any of my 4 mix stuff. I run a FS 90R (same engine as the KM 91R) and it has been flawless. My BR700 is also 4 mix, and runs great.

ETA - you can't go wrong with either - however once I switch over to the kombi system next spring, I'll be getting a KM 111R...more power for not much more money.

Thank you for the reply. The KM 111 R could definitely be a contender if I go with the 4 mix. It's only $10 more than I was ready to spend on the 94.

4 mix engines NEED a valve adjustment at ~60-70 hours or you will have serious issues, many people don't know this.  Lots of complaints of failed 4 mix motors because owners never did this.  You can tell the valves need adjustment when the pull start has increased resistance.  10 minutes to do it yourself or $35 for the shop to do it. I like my 4 mix equipment a lot, I do the valve adjustments and have zero issues.

Stihl recommends at least 89 octane non-ethanol, which is what I run and haven't had any problems at all. No one sells non-ethanol 91/93 octane around here, unless I buy cans of the TruFuel which is 92 octane (however it works out to be around $30/gal if you buy that).

I've had a 4Mix edger for about 6 years now and I have had no issues with it whatsoever.  The only problem I have is when someone hits the primer bulb trying to start it.  I've maybe had to use the primer once since I've owned it.  Otherwise, turn the choke on and two pulls at the most.

I have a fs90r 4 mix.  Had it serviced after a couple years of service, lashed the valves. I like the torque and power of the 4 mix, I did get a bunch of water and shit in the carb, couldn't get it running, literally just pulled carb and put a new one on. Fired right up and has run for several years after that. 

The fuel was my fault, can't blame stihl for that. Otherwise it's been an awesome engine and trimmer. 

Thank you all for the feedback. I do like the power of the 4 mix. I want to be able to run the pruning attachment for some of the taller palms. There is no storage or off season in south Florida to worry about. I have a local gas station and several boat docks where I buy non ethanol gas and I also get a deal on the True Fuel 50:1 from time to time. I don't think I will have an issue with doing valve adjustments myself and I have a great local shop if needed. It looks like I am headed into town to buy the KM 91 or 111.

Great day.