The 05 & 06 800's are a great motor though they are known for needing a minimal BUT important couple of "updates" or else your playing with fire! In 07 they fixed these problems and its a easy fix on "our 05's" and gives you peace of mind and adds a bit of punch to them also. First its a known FACT that the intake boots are prone to de-lamination, SPI@$21.95ea. & Kimpex@$19.95ea. make aftermarket ones and are better then the known failure prone stock ones. If the boots are still good you'll want to take out the stock 17.5 pilot jets & put a set of 20's in and turn air screw out 2 turns and that will cure hanging idle. The stock slide needles also need to be updated to the 07 needles which will cure the known lean mid range that has caused many a 800 to lose a piston. Then after you take care of those 2 carb problems you can get your ECU reflashed which will add a bit of timing to take advantage of the extra fuel, its not necessary to reflash, thats a personal choice - I didn't. -- At the dealership you just have to ask for the #20 pilots as for the rest here is a post from dootalk tht is very informative--What’s new:
Mikuni TM 40 flat slide new jet needle and ECU calibration.
• Carburetor needle J8-9EGI05-58 (P/N 404 162 092)
• BUDS. file number available on BOSSWeb (P/N 415 129 253) to update ECU
Why:
• Slightly richer taper on jet needle increases fuel flow in mid- range, part throttle operation. This will efficiently reduce combustion chamber temperatures.
• Improved durability in extreme riding conditions.
Applicable on:
• GSX & GTX 800 Limited
• MXZ 800 R Adrenaline & Blizzard
• MXZ 800 R Renegade & Renegade X
• MXZ 800 R X & X-RS
The new carburetor needle and ECU calibration would fit MYO5 and MYO6.
(NOTE: MY05 & MY06 are the 05-06 P-Tek engines)
CAUTION: The needle and the calibration file have been designed to be used together; using only one item may cause serious engine damage.
If you want to read the whole thread and hear the pro's and con's plus horror stories this is the link to 21 pages of talk on the subject --
http://www.dootalk.com/forums/index.php?showtopic=117364&hl= . Do yourself a favor and do not shim your needles as its a cheesy fix, buy the new ones, its worth the peace of mind. Hope this helps. MaineSled
