Stihl Pro trimmer REALLY hard to pull when starting... how-to fix!!! (Stihl 4-mix valve adjustment) 

Hey Fitch! Thanks for the kind words. Let me know how it turns out! I have the HT131 saw too and I LOVE it!

@@DavesSmallEngines The valves on my HT101 are perfect. Identical light drag on both. Buttoned it right back up with out adjusting anything. Not bad considering we bought it in 2006 when I was 64. I'm still using it fifteen to twenty hours a year, though it seems a little heavier than when I bought it.

These comments are why I make the videos!

Yep - that way shows you at TDC as well but doesn’t guarantee you are on the right stroke. Sometimes hard to see as well so I wanted to show this way with the plug out!!! Thanks for the kind words, Jerry!

Yes it does! Cheers!

Thanks Nina!

My pleasure!

No problem Aaron!

That’s great! I have a few to go over this winter. Need to get my inventory and projects under control!

Let me know how it goes!

More to come! Cheers!

Hey!Thanks!

Hey John! Thanks for the kind words. I have a Kombi KM55 setup I quite like, but if you need more power the next step up is the pro level (KM90, 91, 94 + etc). My Fathers FS85r still runs the same as it did in 2001 when he bought it too!

Hey No Limit! 2 strokes don’t have the same issue. They use ports instead of valves - way less moving parts. If it was hard to pull over and it was a 2 stroke, you were likely correct at the piston being scored from lack of oil in the mixture.

Glad you enjoyed it

Awesome! Let me know how it goes!!!

@Dave's Small Engines I pull the plug and the engine spins easy. I put the plug in and loosened the valves and it is still very hard to pull. I should have the kit next week to set the valves just right.

Hey Jeremy! Thanks for the kind words!

Thanks Jeff!!!

Hey WildeFox! Let me know how that goes!

@@DavesSmallEngines The valves were still in spec, it looks like the crankcase may need to be resealed though, the bottom of the engine is oily. That's usually a sign of a leak, I found a video Don made on how to reseal a Stihl 4 mix backpack blower engine crankcase so I'm going to tackle that next.

@@wildefox1478 yep! It’s a great video. I’ve reseated 3 or 4 in the last couple days based on his video.

@@DavesSmallEngines Just finished resealing the 4 mix on my BR600 backpack blower and man that made a world of difference! Before and as long as I've had it, it had slow acceleration when the trigger was squeezed and had poor idle, must have been lacking in power too because man it runs like a top now! Lots more power, smooth idle and very responsive throttle, it accelerates immediately, so resealing the engine was definitely needed, first time doing a repair like this on a 4 mix.

Hey John! Thanks for the kind words.

Anytime bud 👍🏼

Hey Nash! Good to hear, I’m going to put it to work!

@@DavesSmallEngines I can't remember but if it has a solid shaft do not put any blades on it

They are pretty sweet, eh?

Thank you! Cheers!

Thank you Sir!

Hey Mick! Good to see you in the comments. Hope all is well!

Cheers!

The intake gets adjusted at 0.004 and the exhaust @ 0.008

Ahh okay! Cool!

That way works too!

@@DavesSmallEngines I am a Stihl Platinum Certified Tech 40 years experience , Stihl expresses to follow the procedure to a Tee , because you will be adjusting the valves just prior to TDC very slightly. These are interference engines if the valves open even slightly to much they will contact the piston and break a ring land or a valve keeper and then drop a valve causing a catastrophic failure, there is a reason for the arrow casted onto the flywheel and it not for dummies...!

@@cbnx82703 yes sir! I’ll make that adjustment to my methods. Thanks so much for your time

@@DavesSmallEngines Dave , sir it’s your machine you do as you like but for customer equipment repairs while working in the industry for a cash paying customer and you do it your way and it comes back with a issue related to your described method that I described all of your fellow colleagues are going to know exactly what happened believe me I’ve seen it with new hires ignoring procedures and taking short cuts and ends up biting them in the Ass... I understand your procedure on your own equipment is your prerogative...!

@@cbnx82703 I appreciate it, I’ll do that from now on! I am learning every day.

Exactly right, too tight means less compression.

Hey Ryan - I highly recommend the T27 torx bit. Saves so much time! My Irwin bit *bit* the dust last night, have to order another!

@@DavesSmallEngines I just put one in my cart,it's not that I do much anymore,but the bit I have has been too short when I do need one.

That’s great!!!

Hi Rein! Thanks for the sub! Did you get into the 4 mix? The tension on the valve spring and the nut keeps the proper tension on the rocker arm. Not sure about the Poulan, I have only worked on a couple of those and realized I would rather work on Stihl/Echo/Husky stuff. I would be looking at the flywheel like you did… no key? How is it aligned? If that’s all good I’d check out the coil. I’m looking into a lapel mic! Cheers

Dave's Small Engines Haven’t gotten into the 4-mix yet - working on 3 Poulans and a Craftsman all the same except for cc and bar/chain configuration. Got the 2nd one going and it’s also really difficult to pull but at least it doesn’t jerk back so timing is ok. I’ve done a lot more research and suspect these all come with two issues from the factory. One is plug gap in owner’s manual is.025 and they start cold and hot better at .030. The other issue is air starvation due to bad filter cover design. The fix seems to be creating one or more holes in the filter cover more or less aligned with the strat throat. I’m going to try the larger gap first this morning to see what difference that makes and then drill a 3/4 inch hole in the filter cover. There is no separate crank/flywheel key on these - the flywheel has a place where there is an odd looking protrusion which aligns with the crank slot. One other thing that occurs to me is that because the engine isn’t firing right away on first or second flywheel revolution maybe the starter sprocket isn’t being disengaged immediately because the flywheel pawls aren’t retracting yet. Thoughts on that? I had a Stihl 028 many years ago that was not nearly so difficult to pull over.

@@Rein_Ciarfella hmm… I’m not overly sure. Does the chain move when you pull it over?

Dave's Small Engines I’ve tried with brake on for safety reason but then tried with brake off and there seems to be a very slight improvement, but not enough to really make a difference. In between my other work today (pastry prepping - I’m a baker working out of my home) I’ll be doing the mods already mentioned to see what differences may happen. I should also mention I cleaned this 2nd Poulan up completely prior to starting to work on it and did a full service including fuel lines, primer bulb, fuel filter, cleaned magneto and flywheel surfaces and gapped at .010, pulled and disassembled carb, cleaned by spraying carb cleaner and inspected diaphragms which were both good. Washed out air filter multiple times and dried well. Cleaned out the dry fuel tank, filled with fresh 40:1 premix, filled bar oil. Bar and chain cleaned as well. Once I get this thing running right the only other thing I need to do is sharpen the chain. Waiting now for arrival of my first Stihl 2 in 1 sharpening tool and a 15L ultrasonic cleaner! 😁👍🔧🧰 Oh, and I’ve also got a tach and T-handled Torx drivers on order. Every time I think I have enough tools I realize I want to do a more professional job. 😉

Hey Matt! I believe that is a 2 stroke unit, correct? Pop off the muffler and see if the piston is scored up at all. Keep me posted, we can figure it out!

@@DavesSmallEngines not that bad but I ordered a new one this week along with a cylinder. When I remove the old one anything I should look for?

Hmm, could be a few things. Clutch seized, bad bearings maybe? Or valves very tight.

South paw!

Sounds like the piston is scored up!

Yes its in the back on the round cam gear behind that 4 bolt cover is,,plus scrotched cylinder walls can cause this problem to

Hey Jaime. Thanks for the kind words! Sounds like a carb adjustment issue to me. How old is it? What kind of fuel do you use (ethanol added or non?). Have you checked your fuel filter?

@@DavesSmallEngines I'm not sure how old I'll check when I get home. I only use the premix fuel. I do need to check the fuel filter. And you thank you so much for responding so quickly

@@jaimepadilla9548 no problem! What are your carb screws set at?

@@DavesSmallEngines I'm not sure 🤔

@@jaimepadilla9548 If carb settings do not resolve, there may be a leak in fuel line letting air in. Inside the carb, there may be a blocked inlet screen.

That’s tdc !

No kidding!

The video made me think the tight valve was causing the hard crank when in fact it’s the loose valve right?

Cool!

Hey there! Hmm… could be a bad crank bearing or the piston / cylinder are scored. Pull the muffler off and see if there’s any scoring!

Thanks Dave, the problem is fix turns out it was a compression problem

Yes I did!

Yes there is! I’ll make another video using this method as well.

@@DavesSmallEngines is it replacing the plastic cam

Hey Paul! Its a 1/4-inch Hex Shank to 1/4-inch Socket Adapter. And then its a 1/4-inch hex mini ratchet. Thanks for watching!

@@DavesSmallEngines thanks so much for the information would took me weeks to figure that out , much appreciated take care Dave

Sounds sweet to my ears!

@@DavesSmallEngines No offence intended. I was just saying that any engine,(even brand new ) sounds very different on video

Gauge supplied with RS 110 is stamped 10 but no units. It measures 0.010 mm or about 4 thousands.

It's above and beyond the comfort level for most people I would guess.

Hey there! 4 issues I've come across with it... muffler bolts seized and had to be re drilled + tapped, carb purge bulb, valves, pull cord slack. It's good to go now!

I’m not sure - it came in the kit from Stihl. I’d have to look it up!

It says 10 stamped right thru the gauge. Since 10 mm is almost a half inch, it must be 0.010.

The stamping on my Stihl gauge shows 10. When I measure the thickness, it reads 0.010 mm. Or for old time folks, it is between 3.5 and 4 thousands. Probably closer to 4 thousands.

@@whale508 I think you math is correct.

@@alext8828 Actually, the number in millimeters is not correct. I should have typed 0.1mm which is 4 thousands of an inch.