KX450 intake valves on KFX450
So I am trying to figure something out here, and any input would be greatly appreciated. So I am going to have my head ported and I am looking to change valves and any other, if any, worn out parts that. I don't know if the valves need to be changed but the bike is 5 years old and +/- 75 hours, how long to they last? Thinking of changing them just to be safe, but i don't know.
Now the first big question is: Looking at the valves diagrams for the 2 bikes, the only difference between them is the KFX450 has a SEAT-SPRING (16007A - 16007-0026) on both exhaust and intake sides, and the 08 KX450 doesn't. Is that seat-spring crucial? Because the exhaust valves diagram on both bikes are exactly the same (same parts numbers), except for this seat-spring which only the kfx450 has.
The second big questions and most important one: Looking at the intake valves diagram on both bikes, they are exactly the same (same part numbers), except for the seat-spring mentioned above which the kx450 doesn't have, and the intake valve which has a different part number (12004-0018 vs the kfx450: 12004-0026), despite the fact that they use the same springs, retainers, seals, etc.. Looking at this and since I am porting the head, can I change the intake valves for the 08 KX450 ones, so essentially having the same valve setup has the 08 KX450? If yes, would I include the seat-spring while assembling?
Please find attached a picture with the KFX450 exhaust valve diagram (left) and the 08 KX450 intake valve diagram (right), with the respective differences marked.
- 2012 KFX 450R - OMX Graphics - Hot Cams Stage II - JE 12.8 Piston - Full Dasa Exhaust - Power Commander FC - Lone Star Sport A-Arms - RPM Dominator II Axle - Anodized Triple Fronts and Single Rear Shocks (JOGACA) - 15f/37r - Fuel Customs Intake - CV4 Radiator Hoses - Drenaline Bumper and Nerfs Bars - Reflex Brake Lever - One Industries Clutch Perch - Streamline Braided Brake Lines - GoldSpeed Beadlock Wheels - Alba Racing Grab Bar and Plate Blockoff - ODI Grips - Dyno Tuned
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Last edited by Finadas; 11-19-2017 at 04:48 AM.