Cutting open plugs for jetting (pics)

[NO HAND]

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.

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

 

[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.

??????????

 

[NO HAND]

Should I really try 18 to 1?

 

[Rich Rohrich]

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

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.

 

[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

 

[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.

 

[Rich Rohrich]

up

 

[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..

 

[Dave Dude]

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

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

 

[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

 

[Dave Dude]

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

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"

. 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.

Happy Turkey Day Rich!

Best regards,
Dave Dude
96yz250

 

[Rich Rohrich]

Originally posted by Dave Dude:
Happy Turkey Day Rich!

Dave - Don't forget to mix your Turkey stuffing at 24:1

 

[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.

 

[Rich Rohrich]

up

 

[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.

 

[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.

 

[Ty]

Where can I get these pictures Rich??

 

[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?

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

 

[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.

 

[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)!

 

[KXKen]

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

 

[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

 

[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.

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Ben Walker
00 cr 250
BRC,AMA,NRA Member

 

[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.

 

[Ty]

Thank you Rich...