How exactly do you tune a 4mix?

[SawAddictedFarmer]

How would you go about tuning something like a fs110?

 

[ammoaddict]

I was wondering the same thing.

 

[hacskaroly]

How would you go about tuning something like a fs110?

Should be just like a regular two stroke, but you have to also take into account the lash on the valves - get those dialed in first then work on the carb.

 

[Motorka]

rpm meter ?

 

[huskihl]

Highest RPM under load

 

[EFSM]

Similar to a typical 2 stroke, except closer to peak RPM’s. Don't richen the idle much from peak lean.

 

[SawAddictedFarmer]

How do you sufficiently load down a weed eater?

 

[EFSM]

How do you sufficiently load down a weed eater?

Make sure the line is out the whole way against the line cutter if the shield is still in place. If not most trimmers have about 17” total swath.

 

[huskihl]

How do you sufficiently load down a weed eater?

Remove the line cutter and guard and let some line out so that it’s resembling a load

 

[EFSM]

Remove the line cutter and guard and let some line out so that it’s resembling a load

Echo’s service manuals always require the line cutter intact and at least 095 line (except for the high-reduction gear cases—I can’t remember what recommendation is on them). Other brands may vary. I haven’t used a tach to set a trimmer for years and years.

 

[EFSM]

Remove the line cutter and guard and let some line out so that it’s resembling a load

But if the trimmer is bouncing off the limiter, then yes, this^^100%. Some 4-mix models do, some don’t with standard string length.

 

[Chainmale]

I've wondered about tuning these without a tach, is there such thing as 8 stroking to listen for lol.

 

[Motorka]

personly dont linke 4 mix that 8 stroke sound

 

[bogieboy]

I've wondered about tuning these without a tach, is there such thing as 8 stroking to listen for lol.

I usuallt take them just rich enough to stop the "8stroke" with a full swath of line, so it doesnt sound so obnoxious. Then when it starts the 8 stroke you know to tap the head because it isnt loaded down anymore.

 

[Sloughfoot]

Remove the line cutter and guard and let some line out so that it’s resembling a load

Do your string trimmers have guards, @hacskaroly ?

 

[hacskaroly]

Do your string trimmers have guards, @hacskaroly ?

Scythe's don't have guards...

 

[FergusonTO35]

But if the trimmer is bouncing off the limiter, then yes, this^^100%. Some 4-mix models do, some don’t with standard string length.

That's my one and only gripe about my FS-91. I use it exclusively with a blade and it bounces off the rev limiter constantly at WOT. It's not only annoying but I can't imagine it's good for the engine. Runs smooth at about 60% throttle and still has plenty of power. I wonder if there is a way to put the cruise control dial on it like some of the bigger ones have.

 

[hacskaroly]

I wonder if there is a way to put the cruise control dial on it like some of the bigger ones have.

If you don't have the 91 with the bike handles, take a look at the FS 94 handle, it has a variable throttle. I never really understood the need for it on this trimmer, but if as in your application you want to keep it steady at less than WOT, then it might work for you. All this handle does is retard the trigger at certain levels so you can hold the trigger and keep it at the level you set. It might be a direct swap which would be a win/win for you.

 

[EFSM]

If you don't have the 91 with the bike handles, take a look at the FS 94 handle, it has a variable throttle. I never really understood the need for it on this trimmer, but if as in your application you want to keep it steady at less than WOT, then it might work for you. All this handle does is retard the trigger at certain levels so you can hold the trigger and keep it at the level you set. It might be a direct swap which would be a win/win for you.

View attachment 479838

The throttle cables are different (the 91 has a butterfly carb, the 94 a rotary) but you may be able to swap cables or put a different end on it. Or buy a smaller 2 stroke trimmer. A sharp blade doesn’t need torque.

 

[hacskaroly]

The throttle cables are different (the 91 has a butterfly carb, the 94 a rotary) but you may be able to swap cables or put a different end on it.

It looks the same on the outside!!

Good to know about the cable types, but I suppose if he was determined he might be able to find a work around.