Stihl HS 45 Questions & Answers

There are a number of possible solutions. Have you tried running for a while on partial choke? Try also loosening the fuel tank filler cap (while of course keeping the trimmer horizontal). Its a long shot but if you are taking the trimmer from a warm place into the cold the fuel may contract causing a partial vacuum until the fuel warms up. The fuel cap doesn't have a breather to compensate for this. You may also need to adjust the high speed carburetor setting. With the engine stopped turn the H high speed setting screw (that's the top/front left looking from the underside of the engine) 1/2 turn anti-clockwise. There are instructions for this on page 13 of the HS45 manual and the following site is quite useful. Please let me know if you have any success. https://www.lsengineers.co.uk/blog/stihl_hs45_hedge_trimmer_how_to_adjust_the_carburettor#:~:text=%20Stihl%20HS45%20Hedge%20Trimmer%20-%20How%20to,screw%20%28LA%29%20counter%20clockwise%20until%20the...%20More%20

PeterandJoanne G. A while ago I answered your question about apparent fuel starvation in your Stihl HS 45 hedge trimmer. I have now experienced what appeared to be exactly the same problem and it may be that my solution may help you. I could not get my trimmer to run properly after a difficult start without continuously readjusting the choke. The impression was that the machine was suffering fuel starvation. However, on returning the unused fuel to its container I realised that I had used petrol with a 1:25 oil mixture as used in some of my other machines rather than the usual Stihl 1:50 ratio petrol oil mix. I drained the remaining fuel from the carburettor by pumping the primer and then refilled with the correct 1:50 fuel mix. The machine started immediately and ran perfectly. I raise this because it is possible that this may help solve your problem.

Nope

My new HS45 had bogging/stalling problems from new, Stihl dealers x 2 were useless, Sthil were not interested in a refund- apparently they don't need to comply with australian consumer law. Purchased a $22 no-name HS45 rebuild kit from ebay, replaced the carby, all good, it runs as it should, starts easy, full consistent throttle control, no stalling. Note - if you buy an ebay kit you need to swap the throttle cable ferrule (where the cable locates) from original to replacement otherwise the cable will not seat and return fully, small "C" clip holds in place.

I assume you mean the starter cord? This is approximatsly 92cm when fully extended from the machine for starting so the total length when removed would be 100-110 cm.

As you will see in the Stihl instruction book and the dealer should have told you, like all Stihl petrol powered products, this has a two stroke engine so you should use a petrol oil mix of one part two stroke oil to fifty parts unleaded (non-ethanol) petrol. You can buy two stroke oil at most hardware and garden machinery shops with a special measuring dispenser.

Up is choke

On the right side of trimmer with cutters pointing away from you is an orange coloured lever. Pushing this forward arcing down fully towards fuel primer bulb is in full choke position.

Raiders. Firstly stating the obvious make sure you are using the correct 2 stroke fuel mix and that the fuel is fresh. Secondly, make sure the ignition is 'ON', the choke is 'Closed', and then pump the plastic fuel bubble 8 or more times (until you see mainly fuel flowing and then pump it a couple of times more), set the throttle fairly wide, then pull the starter cord. Once it starts open the choke straight away and ease the throttle back if you want to. If you have to restart after its started do not pump again and leave the choke open. I have several 2 stroke Stihl motors and they all start in a similar way.

Get fresh 91 petrol and use outboard motor 50 to 1 mix . Remove spark plug and Clean off electrodes and centre cone with fine sand paper! NEVER use any wire brush to clean plug end! If you have , throw plug away fit new one ! Reason? The wire brush will leave iron and metal deposit scratches pnnthe centre insulator cone and electrodes ! Can’t get them off again ever ! Spark will jump to any earth nearest centre pin it can under load ! Applies to any motor with spark plugs . If heavy with carbon inside edge of plug use a stiff flat plastic utensil ( cable tie etc) to remove carbon. Wash out and blow out cavity !

Refit to motor. Check choke and throttle valves operate ok and sponge or card air filter is not dirty or blocked ! If fuel is more than 6 weeks old it’s stuffed! The petrol goes off in the mix ! Never use any petrol that has any bio fuel in it! The methanol in it separates after a week from the petrol and ducks on water from the air! Also produces a white deposit on carburettor motors that blocks the jets and electronic fuel pumps .

Good luck !

Global Grandad

New Zealand .

Contact any Stihl shop . Ask the workshop guy how many turns from either end ( flat out or no idle contact ) and wind it in until you get the best high speed rpm . Adjust idle speed Last. Cheers Max AKA Global Grandad NZ.

I assume you mean 3 inch branches - no way, no hedge trimmer will do that. You are pretty much in chainsaw or big hand lopper territory there. This hedge trimmer is pretty good at cutting and will probably do a 1 - 1 3/4 inch branch max if you gnaw around it from several sides. It will cut up to about 3/4 inch cleanly.

No way for 3 inch branches, I use a pole style chain saw for that.

Not sure whether you mean 3" wide branches or 3' long branches. You cannot cut anything wider than about 10 mm (1cm - or less than 1/2 inch) and even then it should be green wood as dry hard wood is asking a bit much of a hedge trimmer. So if it's a 3' long branch with a stem diameter of 1cm or less of green wood it will cut it. Otherwise you need a chain saw or hand lopper or trimming saw.