ATV Torture Forums banner
1 - 3 of 3 Posts

· The Sheriff
1,822 Posts
Discussion Starter · #1 ·
New from J&T Products
A permanent and professional bolt-on solution to the flawed oil design plaguing**'04, '05, & '06 YFZ450 owners. As many have*(suddenly and expensively) discovered, Yamaha*used*a poor and ineffective 'splash design' system for lubricating the wrist pin and piston rod bearing*on their YFZ450 ATVs (model years '04-'06). Yamaha has since addressed this issue on their '07 models by utilizing a high velocity oil pump and*an oil nozzle dedicated to lubricating these critical areas. J&T Products has developed a do-it-yourself bolt-on kit to upgrade your YFZ oiling system to perfectly match the*'07 YFZ oiling system. You simply send your clutch case cover to J&T Products where it will be professionally machine-modified,*retrofitted with the ’07 Yamaha oil nozzle, and*quickly returned to you*with the high velocity oil pump, new case gasket, and new circlip. Upon purchase,*J&T Products will immediately make available to you comprehensive, color illustrated, step by step instructions to perform all mechanical work. The procedure can be performed with minimal mechanical skill and basic tools. All work performed by J&T Products will be done by a certified Yamaha factory trained technician and experienced professional machinist. J&T Products uses only genuine Yamaha parts where applicable. All workmanship guaranteed.*

How important is this?
The motor failures have been initiated in one of two separate areas- the wrist pin (connects the piston to the rod) and the rod bearing (where the piston rod connects to the crank). The moment the wrist pin receives insufficient lubrication during high rpm, it “welds” itself to the piston, breaking either the piston or connecting rod and turning the motor into a weapon against itself. The rod bearing failure at the crank is more of a gradual process. Insufficient lubrication here causes the bearings to wear, weaken, and ultimately self-destruct- which will cock the piston in the cylinder during operation. In both cases, significant damage is done to the piston, cylinder, rod, and crank. We have seen several cases where additional damage was done. It’s important to note, there appears to be no “ safe point” for one to reach- these motor failures are occurring anywhere from the first 10 hours of use to after 3 plus years of riding. We have even seen cases where it happened more than once to the same YFZ. The average cost of a top and bottom end rebuild is over $2000. How important is this upgrade? You decide.

“Oil Mod” vs. “Oil Upgrade”
Is this “oil upgrade” different or better than the “oil mod” that became popular on internet forums? Absolutely. The "oil mod" was basically an emergency fix* to the oil problem. The “mod” requires complete engine removal, the cases split, and a series of channels drilled in multiple areas. The jet used with the mod is set lower in the motor farther away from both it’s source (freshly filtered oil) and it’s target (wrist pin). In addition, the “mod” not only fails to utilize the new high velocity oil pump, it actually LOWERS oil pressure as a result of the additional channels. The “oil upgrade”, designed by Yamaha, is a more efficient and effective design patterned after the “oil mod”. The nozzle is located immediately after the oil filter (freshly filtered) and utilizes Yamaha’s new high velocity oil pump. The mechanical work, with J&T Product’s step by step illustrated instructions, can be completed in a short amount of time with minimal mechanical skill.

What is the turn around time?
In most cases, the modification will be completed and returned with the kit the same day the case cover is received. UPS is the carrier we use most often for domestic shipments. J&T Products is located in Michigan.

OK, I want it. What do I do?
You can purchase the kit and view a printer friendly copy of our comprehensive illustrated instructions from their website, Upon purchase, they ask that you please send your clutch case cover (see instructions), the name it was purchased under, a contact phone number and the address where you would like it returned to:

J&T Products
2475 Tomahawk Dr.
Lapeer, Mi. 48446.

NOTE * Due to a mid-production casting change by Yamaha, a limited number of early 2004 yfz450s have a clutch side case cover that WILL NOT accept the new ’07 Yamaha oil nozzle. J&T Products has developed a high quality oil nozzle that will be used on these limited number of units. The nozzle will operate exactly as the Yamaha nozzle.

Note from ATVTorture: ATV Torture assumes no responsibility for this post as it is being made for information purposes only. We cannot confirm or deny the inbformation provided by


· Registered
103 Posts
Awesome!!!! I believe that will be the first purchase, if I get the YFZ that I have been looking at! Thanks for the info and write up!
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.