Stihl Km 130 R (4 Mix Engine)

I'll be watching this post closely. I have 2, 4 mix BR600 blowers that I bought in late 2012.
My string trimmer is a FS250 which is the last of the two strokes.

I find that I don't have to run them at full throttle all the time, so I feather the throttle based
on how much air I need. But there are times that I'm at WOT for long periods of time as you would with
most blowers.

I never had any trouble with them. Starts on usually the first pull and runs flawlessly. I always use
synthetic oil mix.

I use mine for everything, but bought them for getting the leaves up in the fall. It will blow them wet if needed.

If I remember right, the dealer said that the valves need to be adjusted at 130 hours and I probably put about 15 - 20 hours a year on each.

 

Right before I quit landscaping the boss bought a 4-mix brush cutter...I don't remember the model but it was a beast. We had a big hillside to clear that even the dumbest/bravest wouldn't attempt with the tractor and bush hog. It was way more than our curved shaft trimmers wanted.

I have not adjusted the valves before, but I have seen it done once. It looked pretty easy to do...well within your mechanical capabilities. I think the only thing is you need a special feeler gauge (narrower than usual). I think you do it once after break-in (20-40 hours) then every 100 hours or something after that...but don't hold me to that.

I've heard you'll know when they need adjusted because they get hard to start.

 

Coils are limited and I've had a couple act up and do wacky things. I adjust the valves in the spring on ours at the city. Haven't had a problem with any mechanical wise but have heard the early BR 600 had engine probs.

 

I heard the same thing. I'm OK with mine (date of manufacturing) from what I researched.

The dealer told me about $42.00 bucks to adjust the valves and said you will know when its time when their hard to start. Said it acts like the compresion is increasing when you pull the cord? No other maintence other than the air filter on mine.

Mine have about 30 hours or so and they run like a swiss watch. So far so good.

 

I've been running an FS90R string trimmer for 7 years now, a BR600 blower for 2, and an HT101 for 2. All three have the 4-mix engine. I've also worked on several pieces of equipment powered by the 4-mix.

The trimmer & pole saw do have limited coils as verified above (same as your kombi). All of them will purr right along at WOT loaded or unloaded as long as you want to keep them there with no issues. The valves are very easy to adjust, but I would recommend getting the special Stihl feeler gage; it's the correct gap and also the correct shape (and cheap!). To gap the valves is tough with a standard feeler gage due to the width. The tool from Stihl has a width around 1/8" or so which makes it easy to slide into place on the 4-mix valves.

After many hours of use I've never had to adjust the valves on my trimmer, but I've worked on other pieces of equipment that did need adjusting. When determining if adjustment is needed you need to think about throttle response, how smooth it runs at WOT when under load, and how easy it is to start. As mentioned above, higher compression is a bad thing on these. You won't find a Stihl publication that indicates desirable compression on a chainsaw, but with the 4-mix engines you will - I think the range is somewhere in the vicinity of 78-104 psi or something like that. There is an adjustable compression release not terribly dissimilar to other four cycle engines, so that's independent of the intake & exhaust valves.

On a side note, I have a love/hate relationship with the 4-mix engines. They have a ton of power & torque, but they're also heavy and at times can be challenging to diagnose and work on. The hardest part about getting used to them is if you're accustomed to traditional 2-stroke engines; the 4-cycle seems slow, rough, and low pitched in sound.

 

Run it full throttle all you want. I have a couple fs90r trimmers that are unstoppable. The only repairs have been pull cords and primer bulbs.

Pole saw attachment is great...get an extension too.

Mine are due for a valve check.

Maybe mm will give us a linky to the feeler Guage needed?

 

Its a stihl part so you would have to get it at a dealer ....at least that is what I am picking up from this.

 

It's no problem Dex. Just get the feeler gauge from the Stihl dealer.

 

I'm glad to hear that you like it. I just got a HT131 today, I think they have the same engine. I still want to get a KM130.

 

I've had a FS110R for 6-7 years and it been great, never adjusted the valves though, never any problems.
First and only Stihl I ever owned...

 

I've had a 130 trimmer for two seasons now. It's heavier than comparable two strokes, but it's like string trimmer with a small block attached to it. I love it. Doesn't bog down in anything with .095 line but will break the line pretty quickly. It turns .105 line just fine. That stuff lasts much longer. I was thinking the valve adjustment interval was over 100 hours. After two years of home use(probably 20-25 tanks) I don't think I'm anywhere near that many hours.

edit: stihl says 139 hours