ATV Florida Forum

this is what happens when your 04 yfz450 motors piston rod gives out! ANIALATION

Ahhh, little duct tape and you'll be fine.  :P

ouch that hurts!!!!!

haha i wish it was that easy kuz id do it!

and my crank in my 06 locked up the weekend before.

Some JB weld might do the trick.

there is a simple solution......
GET A HONDA!! :D

I have seen trx450r the same way.

I know
i ljust like to mess with him bout it
cuz he is always givin me crap bout havin a honda

only if it was givin to me! ;)

So thats how you got the two in your signiture?

haha no but i dont like honda for racing mx but htey are good bikes other wise

boy I have seen alot of these in the yfz's its from lack of oil getting to the wrist pin do your self a favor when you go back together get the 07 side cover with the 07 oil pump and nozzle aka:the oil mod if you dont you will be doing this again

steve

p.s I have a couple set's of yfz engine cases at my shop that belong to a friend that may want to part with them

yea this one did have the oil mod. we were probably going to ge tthe whole 07 case but if you wouldnt mind finding out how much he would want and what years they are?

http://cgi.ebay.com/ebaymotors/OIL-UPGRADE-KIT-OIL-MOD-KIT-YAMAHA-YFZ450-YFZ-450-07_W0QQcmdZViewItemQQcategoryZ43977QQihZ019QQitemZ290188368082QQrdZ1QQsspagenameZWDVW

just pour some tussim on it.

I know there 06 cases I will call him and ask him  to se how much $$

I have seen it happen on 07's too.....



There is a way to keep it from happening again. We have some YFZ's that were built in June and July of 2005 that are still running today.

WELL THERES YOUR PROBLEM

damn wristpins... get an 07 oil mod the older styles that people did themselves didnt work 2 well. i know from experiance

yea you guys are the ones that did the oil mod to this one still doesnt protect it 100% ntohing does.

 :o 2:L

It isn't just about the oil mod...it is about the rod.

what about the rod?

There are very few ways to keep a Yamaha engine together. Every YFZ engine that I have seen that has blown up has either only had some type of high compression piston and head work done, or has been completely stock and broken any way. Another major problem is the ignition timing, and when people add an aftermarket non programmable CDI box to the mix, either a piston pin, pin boss, connecting rod or rod bearing will fail.

We have worked with a few very well known aftermarket companies on what was causing the failures they were having with their YFZ engine kits. 

We have a few yamahas running around the country that have had a couple of years on them with nothing but a re ring. These results have shown us that these engines need A LOT more bottom end work than they are getting.

The biggest problem is most people can't afford or flat out won't spend the money to put the proper parts and machine work in the engine to keep this from happening. As well, when you build a race engine even more so with the YFZ's you have to do a lot more costly maitenence to keep them tip top.

Mike
ATP Racing

i def. agree especialy once you put power to them they just dont hold up.
so how does the non programmable rev box mess it up because i have an adjustable srp metals box. maybe that isnt helping anytihing?

The timing map in the box was designed for a stock engine. The SRP and or Pro Comm boxes were also designed to specifically enhance the performance of a stock application. Once you make changes like increased compression or more efficient cylinder head air flow, you have to make adjustments to compensate for the increased performance.

As with any good build, be it ATV or Automotive , years of hands on experience, hundreds of thousands of dollars worth of R&D, tens of thousands of dollars worth of testing equipment, ( Dyno, Flow Bench, ect...) have taught us that not only using the best parts that the many different industries have to offer, the little things like tuning a quad properly, will not only yield the best possible performance, but will keep it running properly for many many hours.

A person can waist a lot of good money if they are unsure of what they want but really need, or if there builder does not have the proper equipment to do the job.

I hope all of my rambling will help you in one way or another. It is no secret that the YFZ's are probably the most prone to engine failure, but they can also be a good quad as well.

Mike
ATP Racing

that engine sucks. are you gonna look for a new motor or a whole new quad?

p.s. i sent ya a pm bout that 250R k-town quad boy #5.

mine is an 04 and still kickin, but i got my fingers crossed  ;)

Don't feel bad here's my Honda

(http://i121.photobucket.com/albums/o211/quadcontrol/quads132.jpg)

YAY!! for 2 strokes!!! 8)

yup ben through to many of them. was gunna get a suzuki but i already have tons of extra parts for my yfzs

haha YEAS. only the best have holes in there motors! more airflow lol ;)
but atleast yours spared your cylinder for you

haha that sucks man i can feel your pain though. my father raced his bike forever gave it to me and after ten mins this is what i did. theres more pieces i just have to get them out of the exhaust :)

(http://i154.photobucket.com/albums/s272/tecatematt/l_21f206540d1eea78413021d12adf3c36.jpg)