STIHL 4 MIX ENGINE

[lawsonstree]

IS IT 4 STROKE OR 2 STROKE IF SO DOES IT GET MIXED 50:1 THANKS JOHN

 

[TLHamel]

Yes 4 stroke
Yes 50:1 mix
Should say so on the fuel cap.

One of my contractors has the new power pruner with a 4MIX engine. Very cool!

 

[lawsonstree]

thanks for the info i was wondering how that worked being 4stroke and 2 stroke might have to go buy one now.

 

[BostonBull]

Its a 2 stroke, thats why you mix the oil INthe gas. It has valves LIKE a 4 stroke. Its a MIX between the two, hence the name 4 mix. It still only takes TWO strokes to complete a cycle of the engine.
Great machines, we sell a ton of them and people love them. Only issues I have seen lately is valves becoming unadjusted. Your local shop should adjust them every tune-up, we do them for free for our customers.

 

[TLHamel]

What'll they think of next? Thanks for the clarification!

 

[Axman]

Hey Boston, Is adjusting the valves hard to do ??? I have a HT 101 that has been out of of comission most of this season because of hard starting and not running all that good. When I have a little more time I have to get this one going and was going to see to see if I could adjust the valves myself. Which will be a new experience in a way from the ususal small engine repair and tuning I do to my saws.

These are good engines. They lack the speed of a true 2 cycle but make up for it in torque, kind of a trade off I guess.

 

[BostonBull]

They are easy. You need two things from your dealer. The first and most important is the feeler gauge that you put under the valves between the pushrod, these are set at a certain MM and you tighten the nut on top until it is firm to slide in and out. the second thing you'll need is a new gasket.

Heres the procedure;
-First get the covers off and spark plug out
-Take the cover off the valves
-Turn the flywheel until valve overlap is achieved, this is when both valves move freely. Watch them as you turn the flywheel. They will both move, in one position both valve will be stiff to move with your fingers, turn one more time and now they will be loose to move with your fingers, this is overlap.
-Put your feeler gauge, skinny end in, under the valve, there is a little slot for it under there.
-Turn the nut on top of the valve until it is slightly difficult to pull the gauge out, it will be hard to put back in. You should feel it dragging.
-Now do the other valve.
-Put everything back together,and might as well put a new spark plug in since the old ones out already.

 

[Axman]

Thanks BB, sounds simple enough, similar to setting valves on a regular 4 stroke engine only your dealing with smaller parts.

Larry

 

[BostonBull]

[ QUOTE ]
Thanks BB, sounds simple enough, similar to setting valves on a regular 4 stroke engine only your dealing with smaller parts.

Larry

[/ QUOTE ]
Exactly and on this one theres only 2 valves and there side bi side so no having to figure out the firing order....lol