hello, I am having a hard time determining the excat year of my zilla. The tag reads 11/87. does that mean that is an 87 or an 88?
also, i have tbular type a frames and I have noticed there are some box structure design a frames from diffrent years? the years with thgis box design seam to be a little lower, why is this, are the shocks diffrent or are there major frame diffrences? also, what years diffrentiate between these diffrent style a arms?
basically, i am looking for as much info as i can about zillas.
thanks

 

You are lucky you got an 88, 87 had some issuses that Suzuki took care of in 88.

 

so does this mean the bike is an 88?

can anyone answer my other questions?

 

Yes it is an '88....it's just like you can get a 2004 car in 2003, meaning they built it at least half a year earlier. My '86 LT250R was built in 10/85

Other answers:

The '87s had the squaretubed upper a-arms and the engine had the bigger reedcage. The frame had verylittle to no changes over the years. The tranny might have been geared slightly different from year to year.

Any other specific questions???

later
Superstar

 

thanks for the information, that pretty much answers all of my questions regarding model years and such. I do have a tuning question that someone might have an answer for.

i went through the carb and cleanedit out, the low speed jet was plugged a little bit and the float needle was worn so i replaced it, but everyhting else stayed the same. The bike is a zilla with an fmf pipe, K&n clamp on and a reed spacer, ervything else is stock. The main needle is set at half way and the main jet is a 450. Does this seem like a good place to be running this enigne, just as a ball park figure? Also, sometmies when i ride the bike hard, and then let off the gas, it will almost dies, then come back to life, and sometimes the engine revs up like it is running super lean and about to die, but the rppm dosent come down until i hit the throttle or shut it down and restart it. What charecteristics of the carb would cause this, what should i look for and what should i adjust.

also, with the idle air fuel screw, the book says to use a 1.5 turn outward setting, if i turn it out more it will lean the carb our tight? in more will richen it, right? is there a good way to set this or should i just mess around with the idle screw and air fuel screw until iget a decent idle.
thanks in advance.

 

It sounds to me like you may be lean if you are having high idle issues...(resists normal idle for prolonged timeframe)

You may also want to do a leak-down test to verify the condition of your engine.

Do some homework on these issues... the LT500 is very sensitive to octane ratings also.
Lean = kaboom
Detonation = kaboom
etc. etc.

Also, the best way to tell b/w '87 & '88+ motors is the number of head studs.
The '87 has 6, '88+ has 7.

Good luck!

 

how are the zillas senistive to octane? i run non-oxygenated 92 octance. The octane level shouldnt effect lean or rich right, as far as i know the octane level only effects preigniton, is this correcT?
thanks.

 

Yes the octane affects the detonation.

What Duneaddict is trying to say is that if your engine has an air leak of some sort it will suck air from there and run lean and more than likely idle high. Usually the air leak is around the base gasket under the reedcage cause that is where the surfaces have less contact area to make a seal.

Am I right Duneaddict???

later
Superstar

 

right on the nuts!!!!!!!!!!!!!!!!!!!!!!. i hadnt thought of an air leak, so i did the old ehter spray test by the reed cage at idle and the engine revved up very noticablly, it seems that when i put the reed spacer in i didnt seal it to well, that problem is solved. Thanks a ton. gotta love onlione forums.

now, i have antoher question. a little carb theroy. by moving the clip up on the main needle, does that lean the air fuel mixture out over the entire rpm, or should i say throttle, range. Or does the needle only really effect the high rpms? I am still running what appears to be a little lean, and the clip is set at the midpoint on the needle, if i moved the clip down to the second ot the bottom spot, or all the way down would this help make the engine run a little more rich? or would it be wise to only change the main jet up by one jet size.? I am currenttly running a 450 main with an fmf pipe, and K&N air box. is a 460 too big?

thanks in advance.

 

You're right on the money superstar!

Octane ONLY affects detonation (Preignition)
A motor that isn't properly sealed will leak when running, thus lean out the mixture to the point of kaboom (Voice of experience here)
Yes, the base gasket is one area on the 500's that is prone to problems, but there are others as well.
That's why it's best to buy/build a leak-down tester and look at it that way.
Crank seals are another killer.... The ether test works for the external seals, as 85LT has found out..

Okay 85Lt, You really need to start studying your carb theory... the web is an excellent place to learn how to jet these things... really, it's not rocket science.
There is no one jet that covers the entire rpm range. The following 'loosely' describes what does what.
Air screw: very bottom, and idle
Pilot Jet: bottom/mid
Needle Jet/Jet needle: Mid range
Main Jet: top end

And, keep in mind that these overlap each other, and changing one does have slight impacts on another.... especially the main.

Now to be more specific: Your question involves the needle and circlip... which in turn will influence more in the mid range area.
By moving the clip up.. you are literally moving the needle deeper into the hole, which makes it leaner.
Likewise, by moving the clip down, you are literally pulling the needle out of the hole farther, thus making it richer.
The clip being in center position is ideal, as it's only intended as a 'fine tune'... feel free to move it around and see what happens.... thats how you will learn.

Your question of "is a 460 too big"... there are way too many variables for me to say... Air density, temperature, barometric pressure (altitude), and mods on the bike.... So there is no 'one size fits all' jetting.
I start very rich (To the point where the motor burbles and smokes like hell) and then go step by step leaner, watching plug color (do a search on plug chops, and learn how to read plug color) until it's very crisp and the plug burns good.
A well tuned bike will literally stomp one that is jetted poorly, so it's worth taking some time and learning how to do it.
be conservative and take small steps... lean is your enemy, so sneak up on it slowly.

Good luck.