Champion RCJ4 or RCJ6Y

[Escape08]

I am currently maintaining my Toro 25cc String Trimmer and noticed a lot of carbon and oil buildup in the spark plug. According to the manual it will take RCJ4 and RCJ6Y. Currently it has an RCJ4 spark plug to it.
If I use RCJ6Y will that eliminate the carbon and oil buildup? In comparison, I have 2 other string trimmers and the spark plugs for both have small amount of carbon and no oil on the spark plug tips (when removed). thanks

EDIT: According to my online research on HEAT RANGE
RCJ4 is COLD
RCJ6Y is slightly HOTTER

 

[Wrenchturner44]

@ Escape08, you should be able to visibly tell that porcelain cone (engine cylinder side of the plug) is longer vs the colder plug. Personally I have always run the hottest plug I could in any 2 cycle engine, especially one that gets possible use during the winter time.

 

[slacktide_bitog]

Neither

Instead, use either
NGK BPMR8Y or BMR7A

NGK's scale is the opposite: higher number means colder

Unfortunately, the only platinum and iridium options are from Autolite:
Platinum: 264 or 2974
Iridium: XST254 or XST2974

Autolite doesn't use a structured part numbering system like NGK, Denso, Bosch, Champion, or even Torch

 

[Brian123]

I am currently maintaining my Toro 25cc String Trimmer and noticed a lot of carbon and oil buildup in the spark plug. According to the manual it will take RCJ4 and RCJ6Y. Currently it has an RCJ4 spark plug to it.
If I use RCJ6Y will that eliminate the carbon and oil buildup? In comparison, I have 2 other string trimmers and the spark plugs for both have small amount of carbon and no oil on the spark plug tips (when removed). thanks

EDIT: According to my online research on HEAT RANGE
RCJ4 is COLD
RCJ6Y is slightly HOTTER

2 things:
What oil are you using?
Do you let this trimmer idle alot or run it on less rpm's?

 

[Escape08]

2 things:
What oil are you using?
Do you let this trimmer idle alot or run it on less rpm's?

SuperTech Syn 2 cycle 40:1
I believe you are on point. I rev less (not full throttle) on this string trimmer to avoid engine noise as a courtesy to my neighbors.

 

[Brian123]

SuperTech Syn 2 cycle 40:1
I believe you are on point. I rev less on this string trimmer to avoid engine noise as a courtesy to my neighbors.

Let me help you out here, you can use whatever 2 cycle oil you want, here is where you need 2 make a decision.
The cheaper 2 cycle oils in your trimmer need to be run at almost full throttle once the trimmer is warmed up. The more expensive 2 stroke oils can be allowed to idle 2 a certain extent.

I have been using Amsoil Saber Pro now for almost 30 years at 40 to 1, and I understand about running it at less rpm's or letting it idle. I have a 1 acre property with woods and I am not going to be revving it at full throttle when I am going to take 30 seconds 2 go 2 another tree.

You have 2 other trimmers, what are they?

If I was not using Amsoil Saber Pro, I would be using:

1) Bel Ray HR-1
2) Maxima K2

Someone here will talk about Echo Red Armour, but that is another 2 stroke oil like the 1 you are using that needs to be revved high once the 2 stroke equipment is warmed up.

 

[slacktide_bitog]

SuperTech Syn 2 cycle 40:1
I believe you are on point. I rev less (not full throttle) on this string trimmer to avoid engine noise as a courtesy to my neighbors.

Then you would want to run a hotter plug than stock.

OPE engines are usually designed to run at full throttle at the speed set by the factory

If noise is an issue, consider electric. They are so much quieter, and you'll wish you switched sooner

If you can't do electric, Honda makes a 4-stroke OHC engine in that size called the GX25

 

[Lubener]

I am currently maintaining my Toro 25cc String Trimmer and noticed a lot of carbon and oil buildup in the spark plug. According to the manual it will take RCJ4 and RCJ6Y. Currently it has an RCJ4 spark plug to it.
If I use RCJ6Y will that eliminate the carbon and oil buildup? In comparison, I have 2 other string trimmers and the spark plugs for both have small amount of carbon and no oil on the spark plug tips (when removed). thanks

EDIT: According to my online research on HEAT RANGE
RCJ4 is COLD
RCJ6Y is slightly HOTTER

I would use the Champion RCJ6Y. It's hotter and the tip is extended more than your current plug. That should help with the deposits. I would dismiss suggestions using NGK plugs. That likely will not solve anything. If they are that good, why were they not the stock plug?