ht101 vs ht 131 spark plugs??

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PaulB84

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why are they listed as different brands in the manual? Bosch USR7AC vs NGK CMR6H? Why wouldn't it be the same brand either Bosch or NGK w a one number heat rating difference?

If memory serves a USR7AC would be a CMR5H

I just realized one of my ht131s is actually a 101 (numbers are all rubbed off, air filter gave it away) Almost had a moment when I realized I was running the NGK CMR6H in the 101, but since thread depth (and of course size and gap) are the same, am I doing any harm running a single heat rating too hot in the ht101? Sure would be nice to have em interchangeable
 
Disregard....not worth it esp when I have other stuff that runs the Bosch as well.

Stupid idea, glad I didn't ruin anything
 
Just to clarify Paul,
The motor on the pole pruners is a 4180 series engine which are made in 3 different displacements based on piston diameter.
4180: FS 90, FS 100, FS 110, and all other 38mm and 40mm bore applications such as HL, FC, HT 101, etc. use a 10mm spark plug:
Bosch USR7AC 0000 400 7009; the NGK CMR5H may be used in production, not sold by STIHL as a spare part
The FS 130 or HT 131 or any other 4180 with the 43mm piston uses a colder plug:
NGK CMR6H 0000 400 7011; the Bosch USR4AC may be used in production, not sold by STIHL as a spare part
The NGK CMR6H is also the correct plug for the 4282 series STIHL blowers, BR 500, BR 550, Br 600
 
Just to clarify Paul,
The motor on the pole pruners is a 4180 series engine which are made in 3 different displacements based on piston diameter.
4180: FS 90, FS 100, FS 110, and all other 38mm and 40mm bore applications such as HL, FC, HT 101, etc. use a 10mm spark plug:
Bosch USR7AC 0000 400 7009; the NGK CMR5H may be used in production, not sold by STIHL as a spare part
The FS 130 or HT 131 or any other 4180 with the 43mm piston uses a colder plug:
NGK CMR6H 0000 400 7011; the Bosch USR4AC may be used in production, not sold by STIHL as a spare part
The NGK CMR6H is also the correct plug for the 4282 series STIHL blowers, BR 500, BR 550, Br 600
When you say may be used in production but not sold as spares, you're talking corporate policy and not physical interchangability?

So my br600 and ht131s can safely share a NGK CMR6H or bosch USR4AC, and my fs90 and ht101 will share a NGK CMR5H or Bosch USR7AC?

Did I get that right?
 
That's correct.

You can order those plugs except for the CMR5H through Stihl.
 
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