YFZ Central banner

1 - 14 of 14 Posts

·
Registered
Joined
·
274 Posts
Discussion Starter #1
first day I had it i took the spark arrestor out, removed the air box lid, and filled up with 110 to make up for the jetting. because the race fuel is thinner then regular 91. it worked great! the thing came more alive. well heres the deal.

yesterday it was prolly 40-45 degress out, i bit colder than the first day i had it. and i know a yfz will walk all over my 406ex no matter the modifications. well we lined them up and me and my friend are equal riders in draggin. well the little ex that could stuck right there beside me 3 or 4 times! i was pissed :angry so wes jumped on the yfz and he thought it was doggish and sloppy a bit too. so im wondering if the yfz is that sensitive to the cold air!? cause i should of eatin my 406ex up with my yfz.
 

·
Registered
Joined
·
141 Posts
i know my 416 will keep right up with my yfz in a drag, although i have never actualy lined them up, i can tell just from riding them both. In fact i think my ex might be a little faster in top speed. My yfz is stock..only the airbox lid is off and rejetted properly. My ex has a 416 national motor with a 36t rear sprocket (stock is 38)...does your 406 have stock gearing?
 

·
Registered
Joined
·
773 Posts
Originally posted by FAST1@Nov 27 2003, 08:35 AM
if you haven't rejetted STOP riding it till you do!  you'll ruin it!
How?
 

·
Registered
Joined
·
1,470 Posts
Originally posted by selector+Nov 27 2003, 04:27 PM--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (selector @ Nov 27 2003, 04:27 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin--FAST1@Nov 27 2003, 08:35 AM
if you haven't rejetted STOP riding it till you do!  you'll ruin it!
How? [/b][/quote]
:what im guessing detonation...thats a result of a lean bike right????
 

·
Registered
Joined
·
631 Posts
didn't know bad jetting would hurt anything besides performance. it isnt like taking oil away from the motor. guess you learn something new everyday

andy
 

·
Registered
Joined
·
631 Posts
Originally posted by YFZCentral@Nov 28 2003, 12:49 AM
Lean = more air less fuel = hotter running engine...
that makes sense didn't think about it that way

andy
 

·
Registered
Joined
·
1,470 Posts
I think leans the worst u can be...cause i just know that if ur running too rich u can foul a plug. I dont think it gets any worse than that tho.
Now that we're on the rich topic. I installed a new spark plug and havent done any real riding, just a getinig about 3/4 through 1st gear in my back yard. Dont do it a lot, just a couple of times. I know u really gotta ride hard for a good reading of the spark plug, but i checked it anyways. I wasnt going too but i had the gas tank out while taking out the parking brake, and decided to check the ol plug. The tip was black....omg, it pissed me off...i thought i was jetted right. So i sat for a while and just sort was pissed. I jetted at a 175 main, and a 48 pilot. That was with the airbox lid off. I forgot that i had left it on and was running it in my small backyard with it on. I know putting it on makes it richer and taking it off leans it out. But will the airbox lid have THAT much effect on the bike. Anyways, all i know is that its black. Cleaned it a little and threw it back in there. Left the airboxlid off and im hoping to god that thatll fixthe richness. Anyways, if it doesnt, should i change the pilot down to 45? The pilot is for the bottom end right? Thats all i was doing, a litllt of 1st gear, so im thinking if its still black after a couple rides, then i should throw in that 45. What do u guys think? I think the mains fine...its a 175. For the mods listed i thought my jetting would be fine. Anyways, help me out if u can...Oh yeah, anyone at Glamis this week, hows the weather out there????? :lol :lol :lol
Again, please help me out guys...thanx...oh yeah, im at sea level. Cause i know someone would be bound to ask that.
 

·
Registered
Joined
·
9,372 Posts
Originally posted by YFZCentral@Nov 28 2003, 04:49 AM
Lean = more air less fuel = hotter running engine...
thats a tech guru stamp right there :lol :lol :lol :lol :lol u must be goin to college to be a rocket scientist :blah :lol :lol :lol :lol :lol
 

·
Registered
Joined
·
256 Posts
Originally posted by FAST1@Nov 27 2003, 06:35 AM
if you haven't rejetted STOP riding it till you do!  you'll ruin it!

Absolutely correct, cold air is much denser than warm air. Real cold air can and will require jetting changes.
Without richening the air/fuel mix, you will cook your piston in the colder, denser air. Richen her up and then hang on.
 

·
Registered
Joined
·
274 Posts
Discussion Starter #14
LMAO nice signature biohazard, thats so true!!

but anyway yea i couldnt believe my main was 158 stock!!! i put a 160 in the day that it felt slow. but im gonna go get a bunch of main jets and pilots and play with it.

boy these 5 valve motors are touchy
 
1 - 14 of 14 Posts
Top