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Cutting open plugs for jetting (pics)

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Posted by: Rich Rohrich---------------------

I've been working on a description of various plug conditions and how to identify them. I haven't completed the text but I thought you guys might like to see a few of the pictures.

http://four-stroke.com/plugs/plugA_shell.jpg

http://four-stroke.com/plugs/plugA_noshell.jpg

http://four-stroke.complugs/plugb_shell.jpg

http://four-stroke.com/plugs/plugb_noshell.jpg

http://four-stroke.com/plugs/plugc_shell.jpg

http://four-stroke.com/plugs/plugc_noshell.jpg

http://four-stroke.com/plugs/plugd_shell.jpg

http://four-stroke.com/plugs/plugd_noshell.jpg


------------------
Rich Rohrich
==

"Wisdom is not a product of schooling but of the life-long attempt to acquire it."
- Albert Einstein


Posted by: ButtonFly---------------------

Very interesting... where will this be posted?


Posted by: Rich Rohrich---------------------

I'll post it here on DRN , and on Eric's site.


Posted by: Buzz Bomb---------------------

Rich, just to see if I know anything about plugs. Is the last plug that you pictured the one that is jetted right?


Posted by: Rich Rohrich---------------------

Don't quit your after school job just yet Buzz, they are all jetted pretty close except for C, which inspite of being white is ~2 sizes too rich on the main for MX, but jetted perfectly fine for trail riding, or woods work. The plug is running a bit too hot for the application.

Just so the "More oil is Bad 50:1 Club" is clear on things, Plug D is from an RM150 running 18:1 and ridden by a complete motosquid (ME) on a really tight track that sees very little WOT running. So much for the belief that more oil will foul plugs http://dirtrider.net/ubb2/smile.gif
The plug isn't running hot enough on plug D to properly clear the deposits from the nose of the insulator which is the ONLY reason it is chocolate colored, it should be much lighter colored (whitish /tan) if the plug were running at the proper temp, but Plug D should give you a pretty good idea what the fuel ring should look like at the bottom of the insulator. That's where you want to look to read the Main jet.


Posted by: cr250john---------------------

Rich,
Really cool!
If your remember last month I took a lathe to the plugs on my CR250 and the kids CR80.

The nose of both bike plugs look cleaner than your plug "D" and the CR250's plug ring is similar in color to "D" and starts approximately 1/16th above the metal base and is 1/16th thick where yours looks to be right at the base. The CR250 was running a BR8ES.

The kids CR80's plug has a very light tan ring that is right at the base and is a hair bigger than 1/32nd and looks just like your "D" plug with a white nose. That plug was a BR9ES. I did go one size larger on the main with the kids bike because is seemed to be lacking a little in top end.

Side note: Were these pix taken with a digital camera or with film and then scanned? I have access to a film camera and macro lens so maybe I'll get some pix of my plugs and we can compare notes.
Great addition to the forums no matter what! http://dirtrider.net/ubb2/smile.gif
Thanks!

------------------
cr250john
Mine '00 CR-250 '95 Yamaha Virago XV-750
Kids '01 CR-80's


Posted by: Rich Rohrich---------------------

John - Sounds like you're pretty close on the jetting. Good job.

I used a $130 3Com Digital Webcam to shoot these : http://buydirect.3com.com/iom_dcms/...-00&SM=HOME_OFF

My expensive Digital camera can't do as good a job with detail shots like this. The 3Com cam has way better Macro capabilities, and a choice of lenses.

------------------
Rich Rohrich
==

"Wisdom is not a product of schooling but of the life-long attempt to acquire it."
- Albert Einstein


Posted by: steve125---------------------

Rich you can hear the stampeed of riders running to their old plugs and compareing them to your pics. Good stuff Rich.


Posted by: tileman---------------------

Well I have been jetting in my 00 cr 250.
Was jetted at main 175 slow jet 48 with
100 octane union 76 with hp2 32/1 mix
Still running rich with gooo out the silencer
So I jetted to main 172 slow jet 42
Still a bit rich but 75% better
Then I started running maxima super M oil at 32/1 with the same 100 race gas a before
WOW did a plug check and running lean the plug was white.
So I turned in the air screw to about 1 turn from out and it now looks like the frist plug (D) in the pics so I would like to know is the hp2 oil too much lubricant
Or is the maxima oil not enough.

Thanks Tileman.





Posted by: Canadian Dave---------------------

Great job Rich! You da man http://dirtrider.net/ubb2/biggrin.gif

David


Posted by: wrench---------------------

COOL VERY COOL!!!!

wrench


Posted by: cr250john---------------------

Rich - All,
Here are links to the plug chop pix from my '00 CR250 and the kids '01 CR80 that I promised weeks ago.
Rich - Thanks for the suggestion of using the computer video camera. I used the one from a video conference setup I have.

CR250 plug click here

CR80 plug click here

What do you think of these?
------------------
cr250john
Mine '00 CR-250 '95 Yamaha Virago XV-750
Kids '01 CR-80's


Posted by: shifter125---------------------

very nice pics. how are you able to verify the correct timing. i read on TSR that the rim of the center electrode will tell you if the timing is on. is the timing on on all of the these? or are there some that are off - which is which?

------------------
SUZUKI-BIREL 125


Posted by: Rich Rohrich---------------------

The specifics will be part of the article, but plug C was running a high dose of ignition accelerator and needed the timing to be backed off some.


Posted by: MikeS---------------------

Quote:
Originally posted by Rich Rohrich:
running a high dose of ignition accelerator .


Interesting product ignition accelerator, I can't wait for the article.....




Posted by: Rich Rohrich---------------------

Paul - I've done some testing with Nology Hotwires and a couple of other "add on" products in automotive applications, and didn't find anything in their operation that would change the plug reading, or anything else for that matter http://dirtrider.net/ubb2/smile.gif

REAL, performance ignition systems like the Jacobs or MSD, will tend to change the look of the tip of the center electrode, and has some effect on the look of the ground strap.

Did you have some specific product in mind?



Posted by: johnv---------------------

Thanks for the pics Rich!

How old are those damn things??? My plugs never look that dark. If anything, they usually look like CR250John's plugs.

Thanks again!
John


Posted by: WWR---------------------

Rich,
I dont remember the name of the plug-cap spark-enhancers, but I can run out and get you a pic of it. If I remember right, most of the large writing on the product is in English, but the detail stuff is in Japanese (I cant read it). Actually, I thought these things might be more usefull in helping with the YZ400/426 hard starting problems than anything else. Its worth a try.
Paul


Posted by: Rich Rohrich---------------------

The only people who have problems starting YZFs are the ones who kick like a 12 year old girl having a HISSY FIT http://dirtrider.net/ubb2/smile.gif





Posted by: Jeff Howe---------------------

Ahhh... a little generalization for those who would never admit to it. Rich, you might have offended some there but will never know it. hehehe


Posted by: Rich Rohrich---------------------

I generalize all the time. I just make every attempt to confine it to things that don't really matter http://dirtrider.net/ubb2/smile.gif


Posted by: Jeff Howe---------------------

Well, I just thought it was pretty funny.


Posted by: Rich Rohrich---------------------

What's may be even funnier is how many people believe it takes some sort of super human effort to start a YZF http://dirtrider.net/ubb2/smile.gif


Posted by: Jeff Howe---------------------

When in fact a 14 year old girl with a stout ankle could do it?


Posted by: Rich Rohrich---------------------

Paul - There isn't much chance that a plug cap alone is going to make any significant difference on a properly functioning OEM YZF ignition system. I realize that fact won't stop people from selling all kinds of bolt on junk. http://dirtrider.net/ubb2/frown.gif
Hard starting issues on YZFs seem to be a direct consequence of two-stroke riders who are unfamiliar with big bore four-stroke starting procedures. I don't really believe four-strokes are harder to start, but the procedure is certainly different. Even at 13.8:1 compression my YZF has always been a first kick starter hot or cold, IF I follow the steps to start it like a BIG four-stroke. Attempting to start it like a two-stroke is just an excercise in futility. Not surprisingly, the AF500 two-stroke shares many of the same traits. Treating it like a 500 and it's a first kick starter. Treat it like a 125 and you'll kick till your leg falls off, or it kicks back and breaks your ankle http://dirtrider.net/ubb2/smile.gif




Posted by: NO HAND---------------------

Quote:
Originally posted by Rich Rohrich:
Just so the "More oil is Bad 50:1 Club" is clear on things, Plug D is from an RM150 running 18:1 and ridden by a complete motosquid (ME) on a really tight track that sees very little WOT running.


Could it be an advantage also when we use race fuel that is really dry? Now I mix 32:1 but I'll try 18:1 and jet the bike for it.

------------------
Sand Del Lee MX Park Rules!!
00 CR125
91 CR250


Posted by: MikeS---------------------

Rich

Can you comment on "race fuel is dry"?

Race fuel may leave a dry appearance on your plug or exhaust due to the complete burning.

??????????


Posted by: NO HAND---------------------

Should I really try 18 to 1?


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by MikeS:
Rich
Can you comment on "race fuel is dry"?


Maybe NO HAND would like to explain what he is talking about http://dirtrider.net/ubb2/smile.gif

NO HAND - On an MX bike 18:1 ratio isn't worth the effort. I did it mostly to test a few things and to prove a point. I usually run 5 ozs oil/gallon on my CR125.




Posted by: NO HAND---------------------

I was thinking that the race fuel I use (Sunoco 110) is dryer than pump fuel because it leaves a white finish when I spill some on the plastics or on my hands. I figured that maybe it was a reason for adding more oil but I wasn't sure that race fuel is dryer. I was kind of wondering two things at the same time and tried to ask it in one question. I'm glad to know your mixing ratio. I was wondering about that too.
Thanks, J-S


Posted by: Rich Rohrich---------------------

Certain fuel additives have higher solvent properties than others. Alcohols (ethanol & methanol) and MTBE have especially high solvent properties, some people term this a "dry fuel". Common non-oxygenated race fuels rarely anything that would cause a problem, alcohol based fuels (including some pump fuels) can cause corrosion problems. If you aren't running alcohol in your fuel it's nothing you have to worry about.


Posted by: Rich Rohrich---------------------

up


Posted by: NO HAND---------------------

Where I live, the Sunoco 110 is the only race fuel availlable and the place I buy it from doesn't know what it contains. Once jetted right, the bike ran fine but I had to park it. Why?? because since three days now, everything is covered with snow. how depressing..


Posted by: Dave Dude---------------------

[QUOTE]Originally posted by Rich Rohrich:

snip

Just so the "More oil is Bad 50:1 Club" is clear on things, Plug D is from an RM150 running 18:1 and ridden by a complete motosquid (ME) on a really tight track that sees very little WOT running. So much for the belief that more oil will foul plugs http://dirtrider.net/ubb2/smile.gif

snip

HEY! Mototsquid my ass. Spect me to believe that? I heard about you. Motosquid, Hah, yeah right, cmon Rich. Will your "test" survive a pathetic rider(me) different oil and different conditions? I'd be interested to see. Let ME ride that thing set up like that. We'll mix some 927 at 18:1 first, then try some Spectro at 18:1, then for grins some Yamalube. You jet it so it's perfect but I pick the oil and creep around some of my North Texas trails with it. Should't be a problem right? I don't know, I think I might want you to provide me a fanny pack full of fresh plugs, just in case. What do you say Rich dude? You might make a trip out of it, bring down Tuner and Gomer too, they loved the sandy creek bed at the Harris Ranch.

Dave "not gonna let you off easy" Dude
96yz250


Posted by: Rich Rohrich---------------------

DAVE DAVE DAVE, you're comparing apples to porcupines. There is no reason to run 927 in a bike that plonks through the woods, and even I wouldn't run 18:1 in that situation, regardless of the oil. It just isn't necessary. With the correct jetting Yamalube would probably fair pretty well but it still wouldn't be necessary to run 18:1 in the woods. There are lots of oils that lubricate well, but have poor combustion characteristics, so there's little doubt you could find oils that don't run well at low ratios. The trick is matching the loads to the volume and type of oil. I'm not sure if your success running 66:1 says more about oil ratios, or how hard you ride http://dirtrider.net/ubb2/biggrin.gif http://dirtrider.net/ubb2/smile.gif


Posted by: Dave Dude---------------------

Quote:
Originally posted by Rich Rohrich:
DAVE DAVE DAVE, you're comparing apples to porcupines. There is no reason to run 927 in a bike that plonks through the woods, and even I wouldn't run 18:1 in that situation, regardless of the oil. It just isn't necessary. With the correct jetting Yamalube would probably fair pretty well but it still wouldn't be necessary to run 18:1 in the woods. There are lots of oils that lubricate well, but have poor combustion characteristics, so there's little doubt you could find oils that don't run well at low ratios. The trick is matching the loads to the volume and type of oil. I'm not sure if your success running 66:1 says more about oil ratios, or how hard you ride http://dirtrider.net/ubb2/biggrin.gif http://dirtrider.net/ubb2/smile.gif


Thank you Rich, that's more like it, I just could'nt let you get away with a "slam" on the 50:1 and up gang. Looks like I may need to visit here frequently, might help keep you "more honest" http://dirtrider.net/ubb2/smile.gif. Ride hard? I am supposed to do that? Not just No but Hell No! I'm going back to too rich jetting-the YZ got major boost with jetting correct, last ride I busted my ass only 150 yrds from the truck, broke my right fibula. I can't resist pinning it when it runs so well, geez it's a rocketship like that and I'm over my head in about a millisecond. And that's with the 13oz fww on. Nope, I'm going back to too rich so it takes a little while to spool up rpm's. http://dirtrider.net/ubb2/smile.gif

Happy Turkey Day Rich!

Best regards,
Dave Dude
96yz250



Posted by: Rich Rohrich---------------------

Quote:
Originally posted by Dave Dude:
Happy Turkey Day Rich!


Dave - Don't forget to mix your Turkey stuffing at 24:1 http://dirtrider.net/ubb2/smile.gif




Posted by: Bill Purcell---------------------

I have a 2000 YZ 250 that now has a Vforce delta reed cage, a Pro Circuit Shorty silencer and I run VP C12. I've been leaning out the jetting to compensate for the mods and the fuel. It seems to be running well, but the plug seems strange to me. About half of the plug is almost white while the other half or third is light grey/tan. What could cause this and do I need to worry? Like I said it seems to be running well. There's no bog down low, so I don't think the pilot is too lean and it feels pretty strong on top.


Posted by: Rich Rohrich---------------------

up


Posted by: YamaBob---------------------

Bill: My 2000 YZ250 (in Florida)is jetted leaner on the bottom & mid (1 step leaner pilot jet , 2 turns out & stock needle 1 notch leaner) but much richer on top for deep sand (190 main). Try jetting the main richer, you will notice the difference.

The half darker/half lighter appearance is common on (production) 2 strokes and is not a cause for worry. Jet the top end richer and richer until you notice a loss of power, back off one step & enjoy! BTW, I run Amoco 93 octane (40:1) in heavy, deep sand & have no detonation.


Posted by: Bill Purcell---------------------

Thanks YamaBob. Last weekend it started to cool off here in California and I developed a little bit of a bog down low, but I was able to fix that with the airscrew. I also put a richer main in and it seems to be running well. Thanks for the info on the richer main, I'll experiment with it.



Posted by: Ty---------------------

Where can I get these pictures Rich??


Posted by: cr250john---------------------

Ty
While waiting for Rich Rohrich, how about some pix of the plug chop on my '00 CR250 and the kids '01 CR80?

The CR250 is setup as follows:
main-175
pilot-42
air screw-2.5 turns out
needle-A735/289R in the 3rd clip position.
Amoco premium pump gas mixed 32:1 with Mobil-1 MX2T.
Altitude-sea level

I don't have the CR80 specs with me today but I can supply them later if needed.
Here are the pix.
CR250 BR8ES Plug
CR80 BR9ES Plug

Any help?

------------------
cr250john
Mine '00 CR-250 - '95 Yamaha Virago XV-750
Kids '01 CR-80's


Posted by: sKiNNyWhEaT---------------------

all thats needind is to learn where to start the kick in the piston cycle. i can start my xr430 with sandles on and almost ZERO effort!
all thats really required is speed in the kick!. i bring the piston almost 1/4 past TDC using the compression release. i use this same kick on a 01 xr650, and get the same results. i find my bike so super easy to start, where others struggle till their legs are dead.


Posted by: Ty---------------------

Skinny, I'm willing to wager that you get some mighty strange looks cast your way while amidst groups of conversing individuals...My advice; open your ears(and read the fine print)!


Posted by: KXKen---------------------

I'm I the only one having trouble setting these pictures to come up?


Posted by: Rich Rohrich---------------------

No Ken, it's not your fault. My ISP screwed up my temp webpage so I moved them over to my www.SuperTTR.com site. The new links are below.


http://superttr.com/plugs/plugA_shell.jpg

http://superttr.com/plugs/plugA_noshell.jpg

http://superttr.com/plugs/plugb_shell.jpg

http://superttr.com/plugs/plugb_noshell.jpg

http://superttr.com/plugs/plugc_shell.jpg

http://superttr.com/plugs/plugc_noshell.jpg

http://superttr.com/plugs/plugd_shell.jpg

http://superttr.com/plugs/plugd_noshell.jpg


Posted by: bwalker---------------------

Rich, Would it be alright to do plug chops on asphalt. I would think it would simulate a high load situation well becasuse of the total traction your tire gets on that surface. It would be easier for me to do chops at my house than to trailer the bike somewhere to do one plug chop. Btw I live in a rural area so my neighbors do not mind.

------------------
Ben Walker
00 cr 250
BRC,AMA,NRA Member


Posted by: Rich Rohrich---------------------

I did a LOT of jetting runs on my YZF on asphalt with a 17" SM rear wheel and a 755 on the front
Asphalt will give you a much more predictable environment, and I think ultimately better results.


Posted by: Ty---------------------

Thank you Rich...


Posted by: ricky1---------------------

Rich, pictures are great, but I was not able to find the text. I looked on your thumper site and Eric's site but no luck. Am I missing something, or is it not up yet?


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by ricky1
Rich, pictures are great, but I was not able to find the text. I looked on your thumper site and Eric's site but no luck. Am I missing something, or is it not up yet?


I haven't had time, so the text is just what's in this thread at this point.

Ivan - It's tough to tell from your pictures but I'd play safe and go with the richer main. If you want to send the plug to me it may help some.


Posted by: rick#3---------------------

Rich or anyone with jetting experience. With being new to jetting and especially jetting on a 4 stroke, how does the 4 stroke behave when running lean and or running rich. I'm working on my 426 to run with C-12.



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