Stihl KM130R loss of compression

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KarlD

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Morning gents

I’m going to strip the engine down and have a look at what has happened; in the meantime I thought I’d detail what happened here in case anyone has an idea what might have occurred.

I was running the machine when it cut out. Trying to restart I found no resistance when pulling the starter. I assumed the spark plug had worked loose but unfortunately not.

I took the spark plug and exhaust off to try to have a look at the P&C but couldn’t see a great deal so just chucked the engine back on the truck and got the spare out.

Half an hour later at lunch I had another look and it started...but stopped again with no resistance on the starter. It feels like zero compression.

When hand turning it feels like the piston is smooth and that it is running the cylinder nice and cleanly...which makes me think it is a problem with a valve.

On the way home I dropped the engine into a local Stihl dealer, a very good one, and they just called me back. They haven’t disassembled it fully but they have checked the valve clearances etc and can confirm no compression; they suggest either an engine rebuild at circa £500 or buy a new one.

Luckily I have a spare and I’m willing to have a look at the broken one myself and I have you guys to quiz. I’ll update the thread with pics when I get into it...sods law I’ve just started an 038S rebuild.

Thanks
Karl
 
Is that a 4-mix motor? Could have a valve sticking.

I'm looking at getting one of those for use with pole saw, brush cutter, and string trimmer. How has it been before it died?

I think the powerhead only goes for ~ $390 USD here
 
Morning gents

I’m going to strip the engine down and have a look at what has happened; in the meantime I thought I’d detail what happened here in case anyone has an idea what might have occurred.

I was running the machine when it cut out. Trying to restart I found no resistance when pulling the starter. I assumed the spark plug had worked loose but unfortunately not.

I took the spark plug and exhaust off to try to have a look at the P&C but couldn’t see a great deal so just chucked the engine back on the truck and got the spare out.

Half an hour later at lunch I had another look and it started...but stopped again with no resistance on the starter. It feels like zero compression.

When hand turning it feels like the piston is smooth and that it is running the cylinder nice and cleanly...which makes me think it is a problem with a valve.

On the way home I dropped the engine into a local Stihl dealer, a very good one, and they just called me back. They haven’t disassembled it fully but they have checked the valve clearances etc and can confirm no compression; they suggest either an engine rebuild at circa £500 or buy a new one.

Luckily I have a spare and I’m willing to have a look at the broken one myself and I have you guys to quiz. I’ll update the thread with pics when I get into it...sods law I’ve just started an 038S rebuild.

Thanks
Karl
Check your inbox for some manuals
 
Is that a 4-mix motor? Could have a valve sticking.

I'm looking at getting one of those for use with pole saw, brush cutter, and string trimmer. How has it been before it died?

I think the powerhead only goes for ~ $390 USD here

Yes 4 mix. I didn’t know this until this problem happened and I went to check the piston and cylinder.

The machines run strong and are very versatile. I have pole saw and hedge trimmer attachments and the carbon shafted extensions...which in use are noticeably lighter than the slightly cheaper metal shafted ones. I use mine a lot, mostly for high hedges.

After the Stihl dealer had a look I took it to a 2 stroke engine specialist I use and within 40 mins he called me back and said he had re-gapped the valves and that it was working again. £20 :rock:

Idk how the Stihl dealer got it so wrong but I guess they couldn’t be arsed.

Since repair it is a bugger to start (got a basic service kit on the way), feels like it has less compression but otherwise runs strong and reliably.
 
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