# Stihl HS45 hedge trimmer



## Bobby Kirbos (Nov 27, 2019)

It's here because it's not a chainsaw, but it could apply there too, so here goes.

@James Miller hooked me up with this trimmer in need of some TLC (busted handle). One eBay frame and a couple hours moving the mechanicals into the new frame, and I have a 24", gas powered trimmer (extension cords suck).

Here's the problem, it doesn't start without some help. I have to throw some mix or a quick shot of carb cleaner down the carb, and it starts in 1 or 2 pulls. Once started, it runs great.


Compression is good.
Fuel lines are good.
Responds well to small carb adjustments.
Idle RPM does not change when turning the engine on its side, so I believe I can rule out crank seals.
New plug (BPMR7A)
New OEM coil (1308)
I skipped a carb kit because it runs well... once it gets started. 
Does a carb kit fix this problem? 
Is there something else that I should look at?


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## DND 9000 (Nov 28, 2019)

Do you use the choke? Is the choke plate closing properly?


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## Bobby Kirbos (Nov 28, 2019)

Yes and yes. 

One thing I forgot to mention - once it starts the first time, restarts are 1 pull.


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## DND 9000 (Nov 28, 2019)

Well, hard to say without having the machine on the workbench to have a look at. Maintenance to the complete fuel system wouldn`t be a mistake, even if it runs good. Is the gap between the ignition module and the flywheel properly adjusted too? Specification is 0.012"


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## Bobby Kirbos (Nov 28, 2019)

Coil/flywheel gap is 0.012".

I have a carb rebuild kit on order, so hopefully that fixes the problem.


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## DND 9000 (Nov 28, 2019)

Bobby Kirbos said:


> Coil/flywheel gap is 0.012".



Yes I know, I`ve written it, but without the 0 on the .012. Corrected now.


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## Cope1024 (Dec 12, 2019)

Good luck with your repairs. I have this trimmer, and it's nice. Mine has always been slow to start.


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## Bobby Kirbos (May 3, 2020)

Update:
Ok, this one made my head hurt, but I got it.

Carb rebuild kit, no change from OP.
I replaced the entire intake stack with a $15 chicom kit. Still no change.

Then I replaced the only piece of the intake stack that was untouched... the gasket between the plastic intake block and the engine (gasket paper and a razor knife). That did it!! 4 pulls and we're off to the races.

Of note, when I disassembled the intake stack (again), it looked like (on the gasket) there was some bleed-over between the impulse port and the intake port. My best guess is that this gap prevented the impulse from pumping the carb, but once running, either thermal expansion closed the bleed-through, or the impulse was strong enough that it overcame the small leak.


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