Small engine repair

[Matt Ellerbee]

With all of the equipment I see, thought I could post some helpful hints to keep your personal OPE in tip top shape. Newer Stihl stuff is mostly T27 torx. Sometimes you will find a T20 and T25 on the smaller screws. Old Stihl is pan head screws (Flat head), but was mostly phased out in the 80's.

First will be a Stihl weed eater, or string trimmer/weed whip for them northern folks.
This unit is a runner, just needs some easy maintenance.
I will be adjusting the valves, cleaning and gapping plug as well as re spooling the trimmer head.
For the valves, we have to remove the engine cover.


That gets us here.

 

[2Glocks]

Yassssss!

 

[Matt Ellerbee]

I pull the plug and recoil assembly next.

Next is the valve cover. Be careful, there is a cork gasket there. If damaged, unit will not run/or will run very badly, possibly burning up the piston and cylinder. They are cheap from dealer p/n 4180 029 0500. Fits all FS models.
Spin motor by hand clockwise. You can see the rockers move. You want the magnet at the coil pickups. Both valves should be fully seated.

 

[Matt Ellerbee]

Jab your feeler gauge in there. P/n 4180 893 6400 is same for all Stihl 4 mix engines.

The rocker nuts are 8mm. Tighten 1/8 turn at a time. You want just slight resistance while pulling feeler gauge out. I go just a touch more. The gauge should go in and out with some resistance.

Remember this was a runner, I wire brush plug and set gap to .025-.028.
Reassemble everything, valve cover has torque spec, I just hit all bolts with a few battery Ugga duggas.

 

[EugenFJR]

Did you check the water pump? Might be the reason is running hot...

 

[Matt Ellerbee]

Let’s move on the the trimmer head. You would think that was rocket surgery, after watching people struggle.... Stihl auto cut heads are easy. Push the two tabs to release the cover, push in and twist the spool to remove. You end up with this. I pull an arms length, hand to hand stretched out of line, plus about a foot. Insert into hole as shown.

Now bend back over itself. And wind fully. You have to do the bottom first.


Repeat for top section.

 

[Matt Ellerbee]

Insert full spool into assembly. Note where line exits, line up and twist to lock in.

Insert line as shown.

Replace bottom cover and I pull both lines to lock into place. You are ready to wack some weeds!

 

[dial1911]

Awesome! I'll be looking forward to more tips.

I think an old spark plug has sent more than one tool to the dump.

 

[Matt Ellerbee]

Awesome! I'll be looking forward to more tips.

I think an old spark plug has sent more than one tool to the dump.

Indeed! Usually the first thing I change if something isn't running.

I will try and do a blower next, same maintenance. Show off my spark tester too.

 

[EugenFJR]

Indeed! Usually the first thing I change if something isn't running.

I will try and do a blower next, same maintenance. Show off my spark tester too.

Can I just bring you my broken lawn care shit and pay you in 9mm/ .223 ?

 

[Matt Ellerbee]

Can I just bring you my broken lawn care shit and pay you in 9mm/ .223 ?

Of course! I accept payment in beer also.

 

[erkinator]

With all of the equipment I see, thought I could post some helpful hints to keep your personal OPE in tip top shape. Newer Stihl stuff is mostly T27 torx. Sometimes you will find a T20 and T25 on the smaller screws. Old Stihl is pan head screws (Flat head), but was mostly phased out in the 80's.

First will be a Stihl weed eater, or string trimmer/weed whip for them northern folks.
This unit is a runner, just needs some easy maintenance. View attachment 114318
I will be adjusting the valves, cleaning and gapping plug as well as re spooling the trimmer head.
For the valves, we have to remove the engine cover.
View attachment 114319
View attachment 114320
That gets us here.
View attachment 114321

got one in the attic I need to get running.Daughters old boyfriend left it. Not run in years.this will be helpful thanks.

 

[erkinator]

Jab your feeler gauge in there. P/n 4180 893 6400 is same for all Stihl 4 mix engines.
View attachment 114331
The rocker nuts are 8mm. Tighten 1/8 turn at a time. You want just slight resistance while pulling feeler gauge out. I go just a touch more. The gauge should go in and out with some resistance.
View attachment 114332
Remember this was a runner, I wire brush plug and set gap to .025-.028.
Reassemble everything, valve cover has torque spec, I just hit all bolts with a few battery Ugga duggas.

Piston at what part of the stroke before adjusting?

 

[Matt Ellerbee]

Piston at what part of the stroke before adjusting?

While rotating engine, when the exhaust valve starts to open, stop and rotate counter clockwise 1/4 turn or so. Should put the magnets just at the coil. That should have you in the middle of the power stroke.

It doesn't make sense reading it, but once you see everything it will.

 

[Bigigloopt2]

Of course! I accept payment in beer also.

I can attest to this

 

[Kobayashi]

Interested in maintenence tips for my chainsaw, a Stihl MS 290. It hasn't been run for a couple of seasons and I need to get it ready for spring.

 

[Matt Ellerbee]

Interested in maintenence tips for my chainsaw, a Stihl MS 290. It hasn't been run for a couple of seasons and I need to get it ready for spring.

Was it stored with fuel in it?

 

[Kobayashi]

Was it stored with fuel in it?

I believe it's empty, but it's probably best to consider the worst case scenario.

 

[Matt Ellerbee]

I believe it's empty, but it's probably best to consider the worst case scenario.

Hopefully it was drained and ran dry. If not, I would tear down and get carb off, check membranes, if still flexible they are probably ok. If any crack or are not flexible, replace them. Ultrasonic the carb, but Brake clean in all the holes will work in a pinch.

Before tossing carb back on, check impulse and fuel line, should still be rubbery and strong, ethanol will turn them to mush. Prob wouldn’t hurt to do a fuel filter too.

If that checks out, put in some non ethanol fuel with your choice of mix. Bar oil. Fire it up.

Every Stihl saw I’ve messed with, is particular of its starting procedure. With a cold saw, place master lever in choke position, 3-4 pulls or until she pops(almost fires up). Place master lever in fast idle and pull till running. If saw is warm, place master lever in fast idle and pull till running.

 

[Matt Ellerbee]

This seems fitting here.
Chainsaw came in “not running right, if at all.” Hmm, ok. First check the fuel. Ahh! Well that was easy. Dump it and refuel with known good. Fired right up.

There was more water than gas.