Question about plug reading...

[05DodgeDakota]

After you read a plug one time, can you use that same plug to do a second, third, etc. reading? Or do you have to use a new plug each time.

Or would it be better/easier to just use the "stumble" method of jetting?

[CJM]

New plug.

I like to run mine a bit rich and then step it down a jet size at a time till the plug reads good.

Start at 175 and see where it takes ya.

[05DodgeDakota]

ok well I hope I can get'er done in three trys then casue that's all the plugs I got in the "shop" lol. If I don;t get it then I'll switch to the "stumble" method lol.

So a 175 you think? 416 12:1 with ported head, hotcam stg 1, powerlid and k&N, and STOCK exhaust (for now) at sea level and 80* weather on 93 pump gas? Also you think I should go down a clip on the needle?

[CJM]

3rd clip on needle will be fine, usually is in most cases.

Im running a 175 on my 426 and its to rich imho-172 was better.

[05DodgeDakota]

another question. Let's say your right and 12:1 is too much for pump gas (even though a stock 06+ 450r is 12:1 and runs pump no problem), how will I know? What do I look/listen for?

[hocman123]

it will not sound right at all with a lot of pinging also the only reason a 450r can run 12:1 stock is b/c it is liquid coolled so the engine can run cooler and not have detonation. i could proberly run 12:1 in a ktm 400 but not a ex

[crownandmonster]

I would tend to disagree with that.. You can use the same plug. A plug that is already colored tends to take color better than a new plug anyway. Just make sure to do a couple runs on it before you do the plug chop. I wouldn't use a heavily soiled plug but one that is in good condition is fine to use over.

[01boneless]

dude your gonna burn that AWSOME (i mean that to great setup!) motor up on pump gas. the reason a 450 can is because they USE COOLANT, whitch runs threw the head to keep it cool!!!! they also have a fan on the rad. please dude try to run race gas. or at least mix 50/50 or with octane booster

[05DodgeDakota]

Does fuel octane affect jetting? What I mean is if I bring some 110 or 100 with me when I start testing my jetting would I have to use a larger main jet to then try running pump gas?

[01boneless]

i belive it does a little try a 175 first then you will know weather to go up or down on the main

[CJM]

I done told ya not to do 12:1..

Run 100 octane.

[05DodgeDakota]

Originally posted by CJM
I done told ya not to do 12:1..

Run 100 octane.

I know what you said. We shall see. I guess to be safe I'll run 100 or 110 while I'm getting the jetting and break-in done and then I'll experiment with pump gas mixes and straight pump gas.

[CJM]

Yepper. Not trying to be an ***, just saying.

Good luck with it, until I was sure it was ok Id run a mix half 100 half 93.

[05DodgeDakota]

I don't think your an ***, your input is very much appreciated. Unfortunately I'm a better rider than a mechanic. I will also keep it rich to be on the safe side.

I'll be mad if I have to run anything more than a mix just because if I was gonna have to run race gas I'd have gone more wild with the build the first time around.

[CJM]

Sok, not everyone can be a supreme puba mechanic like myself lol.

Id run rich and mix it like I said and see what happens.

[crownandmonster]

Just don't run it too fat, or it will have a hard time turning RPM. I generally find the jet that is as close to perfect as I can and then throw the next bigger size in and call it good.

[01boneless]

you should be just fine mixing 100/93 at 50-50. just check for signs of over heating you may end up doing 75-25 mix. i belive me steve and cjm said somthing bout this in the first thread :blah: haha jk

[05DodgeDakota]

Originally posted by 01boneless
you should be just fine mixing 100/93 at 50-50. just check for signs of over heating you may end up doing 75-25 mix. i belive me steve and cjm said somthing bout this in the first thread :blah: haha jk

My problem is I've yet see someone reference a similar build at 12:1. I know I can;t be the first to try it. I should call up Mickey Dunlap and ask him what he thinks lol

[01boneless]

he would say at least a 50/50 mix :devil:

[05DodgeDakota]

haha.

so clutch arrived and is installed. Bolting up the right case cover and I snaped the end off of the arm for the reverse. Luckily there is just enough thread left for me to get a different bolt on there about 2 turns lol. fml. Should be good to go for a first start up in the morning!

[JOHNDOE83]

I hate to disagree with everyone but if you do a plug chop the right way it is completly impossible to re-use the plug.

You have to cut the threads off the plug to read it "plug chop".

[05DodgeDakota]

I was under the impression You don't have to chop it to read it.

Anyways I'm out here testing and I have a 195 in there right now and there is no stumble??? About to pull the plug and have a look

[05DodgeDakota]

Pulled the plug and it looks white with a hint of tan. This is the same plug I did the initial start up and breakin with

[CJM]

Might want to up it a bit. but 195 on your build seems pretty high even given your location.

Honestly you need more ride time sometimes to fully get a good reading and or chop.

[01boneless]

^^ like cjm said put some ride time in it. i belive it was stickman who rebuild a almost stock 400ex and had like a 190 in it and it was still pure white. with a 195 your definitly safe to ride and get a better reading.

[05DodgeDakota]

Well it is actually a cold front today. Down in the 50s. But that's exactly what I'm doing, putting in some ride time.

[Stickman400]

Yep, atleast try and put 30 minutes on it if you can. Otherwise it'll look lean no matter what size you put in. I ended up giving up. I'm putting a 450R carb. on it now anyways, so I'll have to re-jet it and fiddle with it now.

[05DodgeDakota]

Oh and btw, balance and kiser just signed my fender

[CJM]

Geez, now you cant ride it anymore..gotta buy new plastics and save those.

[Stickman400]

I'd see if you can clear coat your plastics or something. Try and keep it from wearing off too fast. Or buy new plastics, lol

[JOHNDOE83]

I think your on the right track, your probaly really close to what it needs to be.

If you really wanna do a true plug chop, pm me and ill give you the details on how to do it properly.

I like the jetsrus method using the stumble technique, some die hard guys go by the plug.

But the plug has to be actually cut open to determine jetting, lookin at color after some ride time just isnt how to do it.

[05DodgeDakota]

Well I put a good hour on the motor, about to go change the oil and take a look at the plug. Also gonna change out my 13 tooth front sprocket back for my 14 tooth. The new power makes the gearing seem too short.

BUT, I drag raced a z400 with supposedly just a slip-on down a gravel road from 3rd gear to the top of 5th and it ran dead even with me till about half way through 5th. I though I should have pulled a length or too on it. The rider did weight probably about 75 lbs. less than I do. Maybe I am too rich and losing power? Or maybe the stock pipe is holding back the motor that much?

[CJM]

Z has more power stock for stock actually and dual overhead cams, kinda hard to beat them. Friend of mine has a KFX (same thing) and he only has a pipe and he is neck and neck with me and easily 40lbs more than me. Id say your probably too rich right now.

I find the EX tends to run out of gears to quick but if I go to a larger front sprocket it takes away too much bottom end. Im thinking of going down another tooth in the rear from 37t to 36t and see what happens.

In reality depending on conditions such as air temp, elevation and such your only really adding maybe 5hp when you do the topend setup that most here run. So from say about 28 to 33hp, stock Z has around 29-30 to start with.

[05DodgeDakota]

I know the Zs are a all-around better bike but I still think I should have pulled more on him quicker. Gotta get a rematch. No time tonight to mess with the bike but I think your right on the gearing, I might go back to a 36 tooth rear as well. btw what brand sprokets do you like best? I like the idea of the renthall twin ring. Aluminum body for less rotational weight but steel teeth for longevity. I also stopped by lowes and bought some clear coat for the signatures. I had them sign where the large warning label use to go which is a spot that don't see much abuse anyways.

[CJM]

Id be willing to bet your running rich as I stated earlier.

As for sprockets-I will run nothing but steel. Aluminum worthless and really doesnt make that much of a difference. Ive run pro taper, JT and a few others, they are all the same really. 37t rear and 15t front work ok for me but I really need to do a 36t rear b/c I tend to run out of power to easy. in 5th Im pushing for another gear lol

[05DodgeDakota]

Okay finally had the time to mess with the bike some more yesterday, but did not have time to go ride it. I did put the stock 14 tooth back in, although I noticed it's about time to buy new sprokets and chain. I changed the oil and filter and this time had alot of what I believe are clutch fibers in it. I actually begining to like this rotella stuff. Anyways as for the plug. I pulled it out and it still does not have much of any color on it! This is the Honda NGK DPR9Z, and I even torqued it to 13ft lbs. This is with about 1.5 hours on the motor total run time and it has me believing I might still be too lean. So i'm gonna order some bigger jets and see what it does.

[CJM]

Why are you running the colder plug? DPR8-Z is the correct stock heat range plug.

You also shouldnt have anything in the oil, but it could just be cleaning the gunk thats left over from the build.

[05DodgeDakota]

Well it says to run the DPR9Z for extended high spped riding. Shouldn't I be using a colder plug for a high compression build?

And with the oil it seemed like there was some white looking bubbles in there, I thought this could be from the clutch breaking in? Shouldn't be from the build, as this is the second oil change since start-up.

is it possible the plug is not reading correctly due to me running race gas? Or could it be lean in the midrange since I haven't adjusted the needle yet and that is why?

[CJM]

Race gas does burn alot cleaner, still should get some reading on it tho. But there is no sense in running the colder plug unless your getting detonation running the hotter plug. IDK I always ran the 8z as does my friend who has a similar build to mine-no issues. I also run all out in desert type environment so IDK why they bother even saying such things.

As for the needle, 3rd notch is what about 95% of people run.

As for the oil, bubbles are fine-fibers would feel gritty.

[05DodgeDakota]

Pluued the plug after two hours of riding and tried to take a picture but it makes it look darker than it is. Plug is a dark grey color.

[CJM]

Dang close lol. Id say your a bit rich nut not enough to worry about. 100 octane or did you try 93?

[05DodgeDakota]

not yet, still running the sunoco 100, haven;t even tried the avgas yet... I went down to a 185 and rode at Croom Motorcycle area with my brother for about 3 hours. Gonna pull the plug tuesday and see what it looks like.

[fearlessfred]

Originally posted by crownandmonster
I would tend to disagree with that.. You can use the same plug. A plug that is already colored tends to take color better than a new plug anyway. Just make sure to do a couple runs on it before you do the plug chop. I wouldn't use a heavily soiled plug but one that is in good condition is fine to use over. x2

[fearlessfred]

all this plug chop stuff is done at wide open throttle thru several gears and the clutch pulled in at the same as you shut of the ignition and then reading the plud before riding again.if not done this way it is a waste of time and a spark plug. and your heat range should be determined by the coloring on the ground stap and not by what someone on this or any other site tells you to run. plug manufacters suggest running colder ranges when running higher compression and h.p. but you should read the ground strap

[JOHNDOE83]

Originally posted by fearlessfred
all this plug chop stuff is done at wide open throttle thru several gears and the clutch pulled in at the same as you shut of the ignition and then reading the plud before riding again.if not done this way it is a waste of time and a spark plug. and your heat range should be determined by the coloring on the ground stap and not by what someone on this or any other site tells you to run. plug manufacters suggest running colder ranges when running higher compression and h.p. but you should read the ground strap


That is not true!

to properly do a plug chop you have to literally cut the plug open!

"Chop" does not mean kill the engine and look at the plug!

This is how a plug chop is supposed to look you cannot reuse it after the "CHOP" if you would like to know how to actually do it PM me.

http://i953.photobucket.com/albums/ae15/johndoe83_2010/Picture0060.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/Picture0062.jpg

[fearlessfred]

http://members.uia.net/pkelley2/sparkplugreading.html
please click on this site and on this or any other it will state that you do a full throttle run and shut down the motor you should also pull in the clutch to get a true reading of the main jet. i do not cut my spark plugs to read them. i have always read them as this site suggests. i guess you couid always ck this methed against the other to see if it is correct.but no matter what way you read it you still have to run thru the gears at wide open throttle and shut the ign. and pull in the clutch to get a true reading of the main jet

[JOHNDOE83]

The link is right, but its only telling you a small part about plug reading.

Theres 3 different jets, each one shows a specific part on the plug, you can only determine pilot and needle settings without physically cutting the plug.

In theory, you only need to plug chop to find main jet settings, you could without cutting the plug or even doing a plug run, setup your needle and pilot jet.

[fearlessfred]

just like you ,i have read every site on this subject, that i could find ,and learned something from each site. the cutting of the sparkplug, is used to check main jetting only and not any other circut is mostly used in drag racing.im not saying your wrong,but im saying you have to do a wide open run to check the main jet. the other circuts can be read on the sparkplug,but the motor needs t o be ran in those circuts to get a proper reading. you can not do an overall reading of the plug and know for sure that all circuts are correct. if your are drag racing your bike only than really care about is the main. I have read the base ring coloring to ckeck the main for a lot of years with great results,on many bikes not just mine. WHATEVER WAY YOU WANT TO READ YOUR PLUG FOR THE MAIN JET YOU MUST RUN IT WIDE OPEN THRU THE GEARS and shut her down pulling in the clutch at the same time.and that is my point