Milwaukee-Eight™(M8) Loose Valve Seats
A quick video to show some issues that we’re seeing with the Milwaukee-Eight™(M8s). We’re doing a leak down on the motors before we disassemble them and we’re finding a 20-25% leak down on the motors. This is attributed to the seats in the heads – the exhausts are loose in the heads. This is going to create an issue down the road with the seats coming loose in the heads and it should be checked. The machining of the seat hole is off.
If we’re doing a bike in-house, we’ll leak the motor down after we get the pushrods to see where we’re at – they should be between 3-5% (no more than that). The heads that are coming in that we are doing that do not have bikes on them – we’ve made a fixture that before we break the head down, we bolt this onto the head and leak down the head by itself. Normally, it will show up very quickly. We also do a drop test on these heads – we heat the heads to press the guides out, we bring them up to a temperature then, drop it onto a piece of plywood to see if it comes loose.
Something that we wanted to bring to your attention. Out of the sets we’ve seen, we’ve had about 6 sets with this seat issue. Keep this in mind – if you’re at your Harley dealership, a leak down test will show the issue.
We are set-up on the CNC machine to machine out the holes, put new seats in and sync everything to the proper depth and get you up and going again.
If you have any questions – contact us at 336-993-7068 or, visit us online at https://tmanperformance.com/
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What are the symptoms?
Can you please elaborate more on how its good to heat a head up of your customer than drop it on plywood? Also is there a Harley Davidson spec for your leak down billet adapter for the leak down? I understand that you have found some bad seats, but out of the thousands made that are good would you say that the quality is not good? Also would you say that if 3-5 % leak down on 2 valves is ok then after doubling the valves you would have double the leak down? So 4 valves at 5% would be 20 % leak down per head? Not really sure I fully understand everything….