Spark plugs: RCJ8Y and RCJ8 are different?

Status
Not open for further replies.
S

seotaji

Joined
Feb 16, 2004
Messages
1,139
Location
USA
I'm not the brightest bulb in the pack, so bear with me.

I purchased a couple of autolite spark plugs, since the guy at the parts counter said they were the same as a champion, but cheaper. So I bit the bullet and got them.

BUT the plug that I purchased for the weed eater doesn't look like the one it's replacing.

I guess I was in a hurry and picked the one that looked similar to it (RCJ8), but the champion plug has RCJ8Y written on it and the electrode sticks out further.

How much of a difference do you think it will make? Should I just take the autolite back and use the champion?
 
R= Resistor
CJ= 14mm thread, 3/8" reach, 3/4 or 13/16" hex
8= heat range with automotive, small engine, and ordnance applications
Y= Standard Projected Core Nose
So the only difference is the projected tip. Won't hurt anything, but may cause poor running and/or hard starting.
-
 
If you had good service with the Champion why change anything? Sometimes, crossing over to another brand may give you a similar, but not exact, replacement plug. Often there are minor variations in heat range etc.
 
I agree, I shouldn't have (and since I haven't used it I can take it back
smile.gif
), but the auto parts store didn't stock the exact champion that I needed (RCJ8Y), but they did have a similar one (RCJ8). Same with the autolites. I thought I could get away with using a similar plug.
pat.gif


wal-mart did have one for $3, so i might just break down and buy one (weed eater brand - champion plug), but i was hoping to get something for half that.
 
quote:
Originally posted by seotaji:
I agree, I shouldn't have (and since I haven't used it I can take it back
smile.gif
), but the auto parts store didn't stock the exact champion that I needed (RCJ8Y), but they did have a similar one (RCJ8). Same with the autolites. I thought I could get away with using a similar plug.
pat.gif


wal-mart did have one for $3, so i might just break down and buy one (weed eater brand - champion plug), but i was hoping to get something for half that.
Click to expand...
Even though the numbers are similar, the RCJ8Y and RCJ8 are entirely different "families". The heat range might be close, but it could also be way off.
You can however use the non resistor version which is a CJ8Y. The (R)esistor just supresses RFI.
You might also check a small engine/lawnmower shop or NAPA
 
quote:
Will the extended tip version reach far enough to touch the top of the cylinder?
Click to expand...
Ah, Duh, meant top of piston. But you already knew that.

If the plug is angled it may not. But I would carefully check it anyway.
 
most plugs for these small 2-cycle engines are extended.
if it is not, it probably wont hit the piston.
 
I'd like to thank everyone for their assistance.

I've proven again that I am not the brightest bulb in the pack.

After calling around, I've found that the trimmer uses a CJ14 spark plug and not the RCJ8Y, which I believe to be totally different and the cause of the hard starting issues.

Hopefully that will fix everything.

By the way, does anyone know the difference between standard and premium spark plugs?

The autolite catalog specifies two spark plugs for my trimmer. The 258 and the SE258DPL or SE258DPT, any clues?
 
quote:
Originally posted by seotaji:
I'd like to thank everyone for their assistance.

I've proven again that I am not the brightest bulb in the pack.

After calling around, I've found that the trimmer uses a CJ14 spark plug and not the RCJ8Y, which I believe to be totally different and the cause of the hard starting issues.

Hopefully that will fix everything.

By the way, does anyone know the difference between standard and premium spark plugs?

The autolite catalog specifies two spark plugs for my trimmer. The 258 and the SE258DPL or SE258DPT, any clues?
Click to expand...
I would assume
SE = small engine?
DP = double platinum?
 
I guess it means "more expensive" as it's at least $2 more expensive than the competitors.

Does anyone know if 50:1 / 8oz. oil to 1 gal gas is too much and would cause hard starting?

The darned thing still doesn't want to crank and I dunno what to do. I've looked at the carb and I know it's getting fuel (replaced the rotted fuel line), but I don't know if the fuel is getting in the chamber or not or if there is too much oil in the fuel.

I'm going to thin out the fuel by adding more gas and check the spark tomorrow. Hopefully it's a problem I can fix. If not, I'll be looking for a trimmer as there aren't any places around here that service my trimmer.
 
whoops then, it looks like i'll be diluting the gallon that i already have.
pat.gif


i found out that the trimmer gets no spark though.

what could be the cause?

should i just dump it and get another one?
 
The magneto either could be bad or too far away from the magnets. Check the clearances first. You'd probably need a service manual to get the exact specs, but it should be just BARELY not touching the magnets as they pass by. You did change to the CJ14 non-resistor plug, correct? Putting a resistor plug on some weedwhackers will cause a no-spark, as the resistance will drop the voltage far enough so the spark can't jump.
 
It would help to know exactly what model string trimmer you have. While you talked about getting a Weedeater spark plug, you never said what brand or model you are having problems with. Most Weedeaters operate with 32:1 gas/oil mix; MTD/Bolens/Poulan, etc require 40:1 and Stihl uses a 50:1 mix. Weedeater info I have is about 3 yrs old, so newer ones may be using a different mix ratio. Without a doubt you need to dilute the gas/oil mix to the correct mix. You may still have some other problems. but getting the gas/oil mix right is a good start.
 
Ah many apologies.

Weed Eater brand model GTI-15T.

I installed the correct plug and still nothing.

I have an older trimmer from the 90's, I looked on the case and it says 40:1.
 
quote:
Originally posted by seotaji:

i found out that the trimmer gets no spark though.

what could be the cause?

should i just dump it and get another one?
Click to expand...
Well, better late than never to know that.
rolleyes.gif


I'm not familiar with these small engines, but that won't stop me!
tongue.gif


Some of these small engines use a kill switch that can work in a couple different ways.

Some ground the coil to kill.
Some ground a lead on the coil to complete the circuit to run.

I would check the kill switch. You could try shorting the wire(s) or try different variations of open/short etc. to see if you get spark.
 
Status
Not open for further replies.

Similar threads

F
Briggs and Stratton Spark plug question ??
Replies
15
Views
2K
Lubener
R
Not familiar with two strokes, what does an oil fouled spark plug and no start mean?
2
Replies
21
Views
2K
blufeb95
P
Stripped spark plug hole on chainsaw
2
Replies
20
Views
3K
Fordiesel69
O
Don't use pre-measured 2-cycle oil bottles unless you filled them...
2
Replies
38
Views
6K
ripcord
J
Oil and spark plugs
Replies
17
Views
766
dumkid
Back
Top