Stihl HL100 Hesitates on Acceleration

[StihlsawuserMS361]

Hope this is the correct forum. Stihl HL100 Extended Hedge Trimmer. Hesitates on acceleration. Starts fine, when the throttle depressed it bogs but doesn't stall. If I wait and hold it WOT, or fan the throttle about 10 times, it will rev up and run fine. Almost like a car's carburetor with a weak accelerator pump. E-Free fuel, Stihl Ultra Oil, valves adjusted, low hours, one owner, exhaust open, light homeowner usage.
Anyone else have this experience?
Thanks to all!

 

[Tony Mayhew]

Hope this is the correct forum. Stihl HL100 Extended Hedge Trimmer. Hesitates on acceleration. Starts fine, when the throttle depressed it bogs but doesn't stall. If I wait and hold it WOT, or fan the throttle about 10 times, it will rev up and run fine. Almost like a car's carburetor with a weak accelerator pump. E-Free fuel, Stihl Ultra Oil, valves adjusted, low hours, one owner, exhaust open, light homeowner usage.
Anyone else have this experience?
Thanks to all!

The first thing that you always do to a 2-stroke engine is turn the idle screw out until the chain, blade, trimmer head stops turning! When you get it to stop turning hit the throttle real fast and see if you have a good response! If it bogged you are lean on L jet! If you have good response leave it right there for L jet. To adjust the H jet you need to go WOT and have a load on the engine and if it's running like never before, then fatten it up it's too lean! They always run the best right before they take a poo! Poo! Richen it up until it just blubbers! That is just where you want it. You have a transfer between idle and off idle on any carburator whether it is on a car,bike, chainsaw, Ect... if you have the carburetor off of a piece of equipment, take a look inside the throttle bore on the side the two jets are on and you will notice a very small hole in front of the throttle plate! And if you open the throttle wide open and you will see that there is another hole on the back side of the throttle plate! The first hole is direct vacuum/L jet and the hole on the back side of the throttle plate is metered vacuum and is only applied when the throttle plate is opened H jet

 

[StihlsawuserMS361]

Thanks Tony for the reply and carb tuning info. I'm just getting wet with Stihl's carbs, but I do have extensive automobile carburetor experience.
Cut off the plastic limiter caps, tried the L / H adjustments and still acted off. Pulled the carb off and removed the plates. I found a piece of orange RTV / silicone sealer under the diaphragm / fuel pump. Apparently, it had been there since it's manufacture, about 20 years ago. Reassembled and adjusted, seems fine.
What did surprise me is that aluminum plate is stamped "china". German engineering, I see.

 

[lone wolf]

Thanks Tony for the reply and carb tuning info. I'm just getting wet with Stihl's carbs, but I do have extensive automobile carburetor experience.
Cut off the plastic limiter caps, tried the L / H adjustments and still acted off. Pulled the carb off and removed the plates. I found a piece of orange RTV / silicone sealer under the diaphragm / fuel pump. Apparently, it had been there since it's manufacture, about 20 years ago. Reassembled and adjusted, seems fine.
What did surprise me is that aluminum plate is stamped "china". German engineering, I see.

All the Carbs I see on Stihl's are made in China

 

[Tony Mayhew]

Thanks Tony for the reply and carb tuning info. I'm just getting wet with Stihl's carbs, but I do have extensive automobile carburetor experience.
Cut off the plastic limiter caps, tried the L / H adjustments and still acted off. Pulled the carb off and removed the plates. I found a piece of orange RTV / silicone sealer under the diaphragm / fuel pump. Apparently, it had been there since it's manufacture, about 20 years ago. Reassembled and adjusted, seems fine.
What did surprise me is that aluminum plate is stamped "china". German engineering, I see.

You never know what you're gonna find inside chainsaws! I always tell people not to pull them over when I'm purchasing a saw! Not like they haven't already done it a hundred times already, Huh? One of the strange things that I discovered on a 330 homelite was that they had broken a thread tap off down inside the hole that holds the carburetor to the manifold! So when you tried to tighten the screw it would bottom out and wouldn't tighten one side down. I thought about some poor old boy that bought the chainsaw back in 1979 and never could get it to run right. I could tell by how good the paint was on the saw, but believe me when I say that it runs very well now and gets used now and then. I own 136 chainsaws so it's kinda hard to find time to run that many!