spark plugs

[woodshop]

Couldn't find answer to this in old posts... seems spark plugs for my saws all boil down to 2 almost identical types. My little echo and Husky 365 take a Bosch WS7F/ChampionCJ7Y... the 2 Stihls and Husky 395 all came with slightly colder WSR6F/Champion RCJ6Y plugs. Sombody just gave me a whole box of WSR6F plugs, same as came in my Stihls. Could I use them in my Echo and 365 even though those saws came with slightly hotter plugs? ...and is there really all that much difference between the two plugs anyway?
Dave
_________________-
this too shall pass

 

[rmihalek]

My Madsens catalog says that the WSR6F can be used in most models of Stihl and Husky. It also says "The old #WS7F should not be used on model 066 STIHL saws with rev limiting ignition."

 

[tmacie]

Just for the record....the lower the number the hotter the plug. The R means its a Resistor plug...most new motors require the R plug, some guys still run the non-resistor plug and have no problems, but if you want to be safe, if it came with a R plug, run an R plug. If you start experiencing pinging with the 6 I would switch back to the 7, you sould be safe though.


Travis

 

[woodshop]

Thanks for the info, this forum is a great resource. So I can use that box of WSR6F's in all my saws. I did jump on Champions site, and they said the lower the number the COLDER the plug, but only for domestic plugs. Most foriegn plugs, as Travis stated, are opposite, and the higher the number the colder the plug. So the Bosch wsr6f is a hotter plug than the ws7f. Tried to find Bosch spark plug site... got tons of other Bosch stuff, but couldn't get thier SPARK plug site, wanted to see if Bosch had anything to say about thier plugs in chainsaws.
Dave

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this too shall pass

 

[jimbo1490]

Just for Cooler/Hotter plug

Just for the record....the lower the number the hotter the plug.....

True for NGK and Bosch, opposite for Champion. Running one number colder plug should not cause any big problems, especially if you are on the throttle a lot. If you sit and idle a lot, the cooler plug will foul easier.

Jimbo

 

[tmacie]

Ahh well....I stand corrected.

http://www.boschusa.com/AutoParts/FAQs/SparkPlugs/

It used to be most plugs the lower the numbe rthe hotter the plug but it seeming like that is changing now. I think it should be lower number colder plug....but we are usually backwards anyway. So I guess it is best to double check with the manufacturer before you assume its a hotter or colder plug. Dave, I still think you'll be ok with the one range colder plug, if you start noticing a lot of deposits on the plug, you may want to switch back. Sorry for the confusion.



Travis

 

[woodshop]

think we got it now

OK, after looking at Champion site, and now Bosch site (thanks Travis), seems that indeed for almost all plugs EXCEPT the Japanese, the higher the number the hotter the plug. Could be others that work like the Japanese, but I was only concerned with Champion and Bosch plugs anyway. So that box of Bosch WSR6F is indeed a colder plug than the WS7F that came in my Echo and Husky. I'm not concerned... going to use the 6F in all my saws, as Madsens says.
Dave
______________
this too shall pass

 

[tmacie]

Looks like most manufacturers are going with the "sensible" numbering system now. NGK is probably the only one that doesn't now, lol.


Travis

 

[tmacie]

I got lucky with the Bosch site....I was looking for a pressure relief valve on their site once.....wow was that a task.



Travis

 

[klickitatsacket]

When playing with plugs be some what careful, especially if you are running high rates of compression. If you get teh plug too hot you can blow holes in the piston. Also when in doubt the long the ceramic the hotter the plug.

 

[Justin Garrison]

With NGK plugs the lower the number the hotter it is. I run a hooter plug in my cr 125 dirtbike in the winter to resist fouling. Neve had a problem with my chainsaws plugs.

 

[Mike Acres]

Listing of Spark Plugs can be found at:
http://www.acresinternet.com/cscc.n...e39d1995d7ddc91588256e0c00029d0f?OpenDocument
if you have a cross over for one that is blank contribute the info

 

[woodshop]

thanks for that link Mike... I have gotten lots of good chainsaw related links from this forum in past couple months. Somebody should put all of these kinds of links in one spot, maybe categorized. Then again maybe somebody already did and I just don't know where to look.

Dave