I'm trying to read my spark plug??

[chris200x]

This is my first experience with a two stroke. I've rode it around maybe a half hour at diffrent rpm's getting the motor brokin in. (just totally rebuilt) I'm running 40:1 and it doesn't seem to be breaking up at all. Looking at the plug (not the best pics) I'm trying to decide if its running lean or not. I think it more on the brown side than white. But I'm not exactly sure what a lean plug looks like. I was wondering if I should go ahead and just keep running it the way it is? :wondering I don't want to blow it up so I thought I'd ask.

[Billy Golightly]

That appears to be slightly lean, to me anyways. But theres not really enough time on it to tell for sure IMO. This same plug pictured here: http://3wheelerworldforums.com/showthread.php?t=67358 turned paper bag brown with the exact same carb settings and a less then 10 degree change in temperature after about 2 hours of riding. You might consider hacksawing the threads off and looking at it on the base of the insulator and see how it looks down in there. The powdery look of yours concerns me...shouldn't be like that.

[chris200x]

Hmm, not sure if this matters or not billy but this is the same plug that was in the first time I fired it up and ran 2 ten minute runs with it just idling in the garage...letting it cool then retorquing the head and cylinder.... then I rode it with varying rpms about a half hour as well. It's not a plug chop per say... I just pulled the plug to have a look. See what confuses me is I'm not sure if I worry about seating the rings first and then dialing it in...or what? Basically I got it started and running.. everything works.. what next????

it's a tri z. I got a 450 main and 45 pilot in there now.. open airbox.....

[Tri-ZNate]

We'll tell ya if its lean this weekend chris :naughty:. But seriously you need more room to open it up if you want to do a plug chop.

[ATC-Eric]

The way I know, you want to be running it pretty rich with oil when your seating rings. I was told to start at 32:1, and work my way up after every tank to 50:1. Everyones got a different opinion though........

[chris200x]

This maybe a dumb question.. but isn't 32:1 even leaner than what I'm running it on now. 40:1.. or to make it easy on me (the newbie :naughty: ) I mixed 4 ounces of dominator to one gallon of gas. :confused:

[Huffa]

This maybe a dumb question.. but isn't 32:1 even leaner than what I'm running it on now. 40:1.. or to make it easy on me (the newbie :naughty: ) I mixed 4 ounces of dominator to one gallon of gas. :confused:

The lower the number, the richer the mixture of oil there is to a gallon of gas which also means since there is less oil per gallon, you are running a richer mixture of gas.

A rich plug should have a black wet look to it. Your plug looks like a four stroke plug I think.

This might help you Chris, has some decent pic's of plugs too ..........

Yours looks like the normal one in pic I think ? but this a 4 stroke plug.

http://dirtbike.off-road.com/dirtbike/article/articleDetail.jsp?id=332655

http://img.photobucket.com/albums/v253/huffa/sparkplg.jpg

[cr480r]

I've rode it around maybe a half hour at diffrent rpm's getting the motor brokin in.

This just gives you an "all around" idea... even with a completely black plug some circuits could be dangerously lean... Do some wide open plug chops with a new plug to get your main jet dialed in... then adjust the needle as needed to clean up the 1/4-3/4 throttle positions... riding around normally and then looking at the plug doenst really tell much...

[chris200x]

Perfect guys thank you. I'm just overly nervous... I don't want to kill it.

[sblt500r]

i would go up a few sizes on the main. that looks to lean for breaking in your engine.

450 main huh? the 88 lt500r comes with a 350 main stock!! thats a big main jet!!

[chris200x]

The next size I have up from that is a 470. I guess I'll throw that in and try it.

Shawn if I'm not mistaken the stock main is a 520 or 570... can't really remember.

[sblt500r]

The next size I have up from that is a 470. I guess I'll throw that in and try it.

Shawn if I'm not mistaken the stock main is a 520 or 570... can't really remember.


wow, wonder why so big?? what size carb is it?

[Huffa]

The next size I have up from that is a 470. I guess I'll throw that in and try it.

Shawn if I'm not mistaken the stock main is a 520 or 570... can't really remember.

Another suggestion is to leave the main as is since it's so large already and lower the clip on the needle. Lowering it, raises the needle, which in turn richens up the mixture from about 1/4 to 3/4 throttle I think?

[chris200x]

wow, wonder why so big?? what size carb is it?

I'm not sure shawn but you brought up a good point in that PM... Why did I jet down if the original main jet was 5 hundred something or other???

I remember someone saying or reading that the tri zs were jetted way to rich from the factory... anyone have any ideas?

[Huffa]

not sure if you saw my needle post since we posted the same time, just wanted to make sure.

[chris200x]

Good point huffa... never thought of that. never checked it either. Man I hate freakin carbs!

I'll see what it's at and start there.... no use ripping the whole carb off if I dont have to.

[Huffa]

Don't go testing it tonight anymore :lol: :lol:

[TimSr]

Its hard to tell from the unfocused picture, but it doesnt look bad to me to begin with. Generally speaking, the old school guideline was any color you would desire to see on a piece of toast is good. A little dark gives you a better margin of error. Since your "reading" is just a general reading during break in and riding around, its totally invalid anyways. Yo need some controlled readings with clean plugs.

There is a nice stickied thread called Jetting 101. Use it! You must do things in proper sequence. You must have the main set correctly before playing with the needle, or your setup will not work. The main affects the needle setting. The needle does not affect the main.

According to Wiseco break instructions, run the same mix you plan on running after break in, unless its oil injected, when you need to add a couple oz. to your fuel, the reason being injectors deliver oil inconisistantly. Ive heard Wiseco knows a little about this, so I tend to believe them.

The 85 TriZ stock jet is 470. Im running 420's in both of mine with a 50:1 mix of Blue Marble, both have Boysen Reeds, one a DG pipe, one a White Brothers Pipe, One ported, one stock, one .020" over, one stock bore.

As for the gas oil leaner richer BS, I try to stay away from those discussions, because I could type three pages of explaining the physics, and nobody would read it anyways, and those who did wouldnt understand it, so Ill just say The More oil you mix with your gas, the darker the plug will be. Nobody ever melted a piston or blistered a plug from too much oil in their gas. They have fouled plugs. The amount of oil in the gas has NO BEARING on the fuel to air ratio. Gas + Oil = Fuel. Changing oil to gas ratios change the properties of the fuel, not the amount of it metered through your carburetor.

By the way, while lean and rich usually is used in terms of fuel to air ratio, technically that is not corrrect either. Rich means delivering more fuel than your chamber can completely burn. Lean means your chamber is capable of burning more fuel than its getting. An example is if your impeller fails and you run it hard, it will run lean, and melt the piston due to a lean condition, even though you never changed the carb settings or changed fuel/air mix, or gas/oil mix.

You can trust that I might know something about this, or not. The information is free, so you can take it or leave it.

[chris200x]

thanks for the sound advice tim. I was actually hoping you'd chime in.. being a tri z vet. I'm well aware of Dammits thread but didn't want to clutter up that thread with all my questions.

So from what I can gather wouldn't the trike be sputtering in the higher rpm's if it was starving from fuel? Like I have mentioned I have absolutly 0 experience running a two stroke... so I must rely on you guys.

I know the pics suck but comparing it to the chart huffa posted it looks pretty close to dead on. I know i didn't do a correct chop.. but I was concerned about running it at all without knowing anything. As I've never broke in a rebuilt motor.

[Huffa]

Some guys believe in the "ride it like you stoled it" for breaking a motor in. :lol:

I prefer the kinder method like your doing :D

[chris200x]

Huffa... I got alot of time and money tied into this thing and don't want to blow it up before I get to the coal pits with it.

[Huffa]

The 85 TriZ stock jet is 470. Im running 420's in both of mine with a 50:1 mix of Blue Marble, both have Boysen Reeds, one a DG pipe, one a White Brothers Pipe, One ported, one stock, one .020" over, one stock bore.



Is that with running the air box lid on or off ? Depending on how some airboxes flow air the lid can make pretty drastic changes and just am curious if it makes a big difference on the Z's?

I'm sure Chris would like to know too. How are the lids held on? Looks like a rubber strap on top but not sure?

I looked on bike bandit to see if they even had lids, they do I see.

[Mosh]

That looks a little lean to me as well.450 main? If you are 60 over or more,I would run the 470 main and the needle in the 3rd groove,or middle groove.I run my Z like that and my plug comes out coffee brown.I am 60 over.I agree with Tim,and one other thing,is the bigger your main,the more oil your engine will get as well,Becuase the concentration of fuel oil mix is in a larger amount with richer jeting..40 -1 is a good safe ratio,with any decent 2 stroke oil.Make sure you dont have any air leaks.Spray a little carb cleaner around the intake boot,jug base and fuel pump vacumn line,and listen for idle changes.These are just guide lines,becuase 2 identical bikes in different locations can require different jetting,due to heat, altitude,and riding conditions.

[chris200x]

Yeah mosh the jug is .80 over.. no lid, boyseen power reeds and a hot rod crank if that matters any. looks like I got some carb tuning to do.

[Dammit!]

Put the lid on and see if it starts sputtering on the top end (prefferably under a good load like up a hill). If it sputters but the sputtering goes away when you take the lid back off, congrats. Your main is fine. If it runs without any sputtering on the top even when you put the lid on, you have room to go up in main jet size (assuming you intend to ride without the lid most of the time). This method may not be ideal for trying to achieve PEAK performance but it works very well for average conditions and use.

The needle/pilot/air screw is a little trickier but cross that bridge when you come to it.

[chris200x]

I don't have a airbox lid even If I wanted to run one Dammit. anyone have one they'd sell me cheap? :naughty:

[Huffa]

Huffa... I got alot of time and money tied into this thing and don't want to blow it up before I get to the coal pits with it.

Yea I know, I agree :wondering

.........so your saying once you do get to the coAL pits, that's when ya blow it up?

Can I come watch :lol:

[chris200x]

OMG... I was just ripping around the yard with it and I guess I didn't have the one hose clamp on tight enough.. well coolant blew out all over my right leg. Let me say this is not too much fun. :( You guys wanna see pics before or after the blisters form?! :rolleyes: :mad:

[chris200x]

I tore my pants off right in the driveway.. and to make matters worse that damn farmer came up screaming at me for tearing up and down the dirt road (As I'm screaming in pain outside in my underwear) :lol: :lol: :lol:

My leg is numb at the moment but there's the pants I had on then the pic of my best freind!!! :lol: and the hose that popped off spraying my leg. Has that ever happened to anyone?

So much for my spark plug thread??? :rolleyes:

[Dammit!]

You guys wanna see pics before or after the blisters form?! :rolleyes: :mad:

Both! Duh. :lol:

[GoodKarma]

Note to self: check hose clamps tomorrow ASAP

Chris, I'm no expert by any means, but I have to agree that your plug seems a little bit lean to me, but not too far off. Is it hard to change the jets as the carb sits on the motor?

If the motor is running lean, it will rev to the moon, and will sputter when it is too rich. (that seems to be my experience, for what it's worth)

[chris200x]

Hahaa! make sure those clamps are tight. coolant is not cool by any means! I'm in too much pain to do anything at the moment, Mike.. but the carb is actually pretty easy to get at.

[sblt500r]

.........so your saying once you do get to the coAL pits, that's when ya blow it up?

Can I come watch :lol:

someone video it! i want to see that!:lol:


chris, i never blew a hose!!! this must be your first watercooled bike!!

[Huffa]

I tore my pants off right in the driveway.. and to make matters worse that damn farmer came up screaming at me for tearing up and down the dirt road (As I'm screaming in pain outside in my underwear) :lol: :lol: :lol:

My leg is numb at the moment but there's the pants I had on then the pic of my best freind!!! :lol: and the hose that popped off spraying my leg. Has that ever happened to anyone?

So much for my spark plug thread??? :rolleyes:

You bust me up sometimes, freakin guy :rolleyes: :lol: :lol: :lol: :lol:

[TimSr]

As I said before, I wouldnt go too much by that plug reading, because it was not taken under controlled conditions. Motors typically run rich during break in due to blow by before the rings wear down enough to mate with the cylinder walls. Id expect to see more deposits, but I cant tell from the picture, and I dont see how anybody else can either. Most cameras have a closeup setting on the menu for this purpose. If you have any doubts about running lean, go ahead and pop the 470 in there to start with. Follow the stickied jetting thread as to how to take a wide open plug reading. Ive got a hunch your going to end up about where you are now. TriZ's tend to be factory rich, and usually end up jetted below stock unless you have some serious engine work. Ive never had to change Z jetting for standard overbore sizes from stock to .080". Monitor your plug and check it frequently on the trails until you have confidence in your setup. Look at the photo Huffa posted. Pay special attention to the glazed look of the insulator on the lean photo. That insulator should look dull and sandy, not smooth and shiney as in the photo. The insulator begins to blister and galze as a first sign of being lean. Other things to watch for - A top end "rattle" noise at low rpm under noise that sounds like a car valve rattle with low octane gas. Also, when lean condition is more severe, youll actually cut out at high rpms, and resume when rpms drop.

Signs of being too rich, besides plug fouling, and dark or oily plugs, it will dog at low rpms, and hesitate and not clean out. Once you get the main dialed in, you can adjust for this with the needle. I like mine a little rich on top at wide open, and somewhat lean at low to mid range to keep it from loading up trail riding. I ended up with both needles at their lowest setting (leanest).

On a lot of machines with restrictive airboxes, removing the lid makes them run leaner from increased air flow. On both my TriZ's, I can not tell the difference, and I doubt you will either. The way the airbox is constructed, the lid isnt highly necessary even under adverse weather conditions.

Also keep in mind the oil you use has a lot to do with the color of the deposits. A lot of synthetics leave a lot lighter color coating on the plug than conventional oils, and create the appearance of being "leaner". Blue Marble is one of those that leaves a light gray color instead of tan or brown.

[Huffa]

YO Tim

Do you run Iridium SP's at all ? Not sure if one in the Z's plug range is even made but was curious if you ever tried them?

My motoxer 02 450R STILL had the original plug in it yet and it still looks fine.

I wonder if one is made for my 84 R ? Think they run between 14 and 18 bucks or so but that's cheap considering how long they last.

[bigreddaddy]

As for the gas oil leaner richer BS, I try to stay away from those discussions, because I could type three pages of explaining the physics, and nobody would read it anyways, and those who did wouldnt understand it,
You can trust that I might know something about this, or not. The information is free, so you can take it or leave it.


Pretty obnoxious statement. Chris, this is YOUR motor so I would simply suggest running it RICH while breaking it in to be on the safe side.
Good Luck.

[TimSr]

Pretty obnoxious statement. Chris, this is YOUR motor so I would simply suggest running it RICH while breaking it in to be on the safe side.
Good Luck.

As I said, take it or leave it. Im not going to fight with anybody to make them use what I have learned, but Im happy to offer it. If you want an explanation of something, Ill be happy to give it, but I think most would rather not hear it, and Im not going to hijack this guys thread to win your approval. Okay, Im obnoxious. That does not factually change the content of anything I have posted. If want an explanation of all the factors, and the physics involved in fuel combustion, start another thread and Ill be happy to discuss it.

[TimSr]

YO Tim

Do you run Iridium SP's at all ? Not sure if one in the Z's plug range is even made but was curious if you ever tried them?

My motoxer 02 450R STILL had the original plug in it yet and it still looks fine.

I wonder if one is made for my 84 R ? Think they run between 14 and 18 bucks or so but that's cheap considering how long they last.


Dont waste your money. Ive yet to find a plug that makes one bit of performance difference that you can detect provided its the correct plug equivilant, inclduing the Champion vs NGK debate. I will mention that in a motor thats fouling a lot of plugs due to other uncorrected problems, the Splitfire plugs will last longer before fouling. Its not a fix, but its a better bandaid.

[chris200x]

Also keep in mind the oil you use has a lot to do with the color of the deposits. A lot of synthetics leave a lot lighter color coating on the plug than conventional oils, and create the appearance of being "leaner". Blue Marble is one of those that leaves a light gray color instead of tan or brown.


This is something I wasn't aware of Tim. Thanks for the useful info!

I haven't really been past 3rd gear yet as I don't have enough room. It's not bogging or sputtering at all in the lower gears so I don't know. It's actually running pretty good at the moment. I'll see if I can figure out that setting on my camera and do a few plug chops before I mess with the carb anymore.

The plugs I'm using are NGK B8ES

[slothminx]

I had the exact same pipe come off at Petesatc's place in the rain, so I didnt notice the water pissing everywhere. I rode for a while until it fouled the plug and I had a good look at it.

Thought id cooked the motor but it must have only been off a minute or two.

[Huffa]

I did a Iridium plug search for the Z ............

http://www.ngk.com/results_appOther.asp?otherMotiveID=113464&mfid=1

[Huffa]

Dont waste your money. Ive yet to find a plug that makes one bit of performance difference that you can detect provided its the correct plug equivilant, inclduing the Champion vs NGK debate. I will mention that in a motor thats fouling a lot of plugs due to other uncorrected problems, the Splitfire plugs will last longer before fouling. Its not a fix, but its a better bandaid.

I'm mainly talking the longitivity of the plug. They may perform a hair better too but that's not my main concern with one.

To detect a actual difference you would have to do a exhaust reading and dyno most likely, I'm sure the gains are minamal and the main goal in designing them was they last quadruple the life of an ordinary plug. Even more then that!

They are not a waste of money. Honda now uses them in their production machines. Not sure how many models but they do use them.

Now the Splitfire ARE junk !! Let the SP flames begin! :lol:

[Billy Golightly]

I think we should make a new thread about spark plugs in the mad scientists lair...

[clutchcargo]

Great thread and info guys! I'm jetting my 85 Tri-z right now also. After reading this, I am questioning my jetting though. It is a stock engine [no porting or head mods], with a UNI-filter w/airbox lid off, DG pipe and silencer, running Yamalube R at 32:1 on 92 octane. The bike broke up real bad at high speed/throttle rpm's with a 370 main. I have since leaned it out with a 320 main and it runs waaayyyy better with a nice tan color on the plug. But, it sounds like everybody else is running richer main jets. The bike runs good, but I feel like I'm running too lean of a main jet now after reading what everyone else is using even though it seems fine. Any opinions?

[firecat]

isnt factory jetting real rich so you dont risk blowing the engine during the break in period?

[chris200x]

isnt factory jetting real rich so you dont risk blowing the engine during the break in period?

I believe thats what the manual says firecat.

I finally got my kill switch working properly. I couldn't kill the motor because I had some wires crossed. :rolleyes: So hopefully I can sneak out to a wide open haul road so I can do a correct chop sometime during the weekend.



I think we should make a new thread about spark plugs in the mad scientists lair...


Billy... I still wanna talk about my burned up leg!!! :lol: :welcome:

[BigGreenMachine]

What you want to do is put in a jet you know is too rich and makes the bike break up in the top end rpm. Then once you know your running rich just jet down the mains until it runs "clean." Confirm the way its running from plug chops. ONce its "clean" or not breaking up in the top rpms and you know your safe from cooking the motor then you can fine tune it which is a little harder with the 10 unit increase Mikuni jets.

Do all this after you have the rings seated.

[chris200x]

Do all this after you have the rings seated.


BGM, THANKS! this is exactly what I wanted to know.

[chris200x]

I need to ask one more question. how will the bike act or what will it do when the plug fouls?

[Billy Golightly]

when the plug is actually fouled, it wont run.

[chris200x]

Will it just shut off when your riding... or bog then die? or run normally but won't start if you shut it off? Can someone be more specific.

The reason i ask is I was riding it and I stalled it. (too high a gear going too slow) It fired back up but would only bog a few feet then die again. I pulled the plug and it looks somewhere inbetween the wet and dry fouled plug pics huffa posted on that chart.

[Dammit!]

You just learned one of the cardinal rules of owning a 2-stroke. Never leave the house without at least one spare plug and a wrench. :lol:

[chris200x]

You just learned one of the cardinal rules of owning a 2-stroke. Never leave the house without at least one spare plug and a wrench. :lol:

LOL... I've only ever owned 4 strokes and never fouled a plug in 20 some years of riding.. This is indeed a new learning experiance. :cry: