Did you try reducing the mic trim more in the camera's menu? For example going from -41db to -35db would reduce the sensitivity of the mic input. I'm not familiar with how much range this setting has on this camera, but it would be important to check fully and see if that gets the clipping under control if you can set it high enough to compensate for the ME64's hot output.

If you do need a new mic that's similar in characteristics to the ME64, perhaps the AT4021 would work for you. It's similar in most aspects to the ME64 but it is only phantom-powered. It has lower output but is still sensitive and has very low self-noise. I like mine a lot but I haven't tried mounting it on a camera, just used it in the studio so far. It's $249 online in the US. It's about 5.6 inches long by 21mm diameter. It would need some additional wind protection for outdoors like a small furry for mics this size.

It was set at -41dbu and now I've set it to -35dbu.
I'll experiment with that setting and see how it turns out. Thanks.

I'm happy enough with the ME64 if I could only get this clipping sorted
I don't have the audio experience to be brave enough to change much in the line of audio settings in the EX3.

Thanks again.

Are -41db and -35db your only choices? If so and -35db is still too hot, you could also add an inline pad (attenuator) to your K6/ME64. They aren't very expensive and if you used one with a fixed value like -10db they are generally pretty short physically. You probably wouldn't have to move the mic forward any, but the pad would increase the length of the mic to the rear.
Make sure to get one that passes phantom power and is designed to work with mics.
This pad, when combined with the menu trim setting gives you a range of attenuation for different situations.
There was also a factory mod for the K6 to drop the output but I don't know if you'd want to go to that trouble and expense as well as having the change in output be permanent.

No, I also have 29,23,17 and 11dbu

I first had the K6+ME66 combo and then swapped the ME66 to a ME64.
I have found the ME64 is not as hot as the ME66 BTW.

That's good news! You should be able to test until you find a setting that works well without having to buy an attenuator or a new mic.

It's true, the ME66 is hotter. But the ME64 is still very hot for a cardioid pencil mic compared to others.

Thanks for the advice Jay

Just curious, how would you rate the RODE NTG-3 to the K6+ME64 as an onboard camera mic.

I haven't used the Rode NTG-3 Shotgun, but it's supposed to be an excellent mic for situations where a shotgun is the best choice. For on-camera use at a wedding, it could be argued that a shotgun isn't best for loud music and crowds inside reception halls and similar situations.
I think you could stick with the K6/ME64 for wedding ambient audio and get as good as you can expect from having the mic on-camera.
If you meant the Rode NT-3 Hypercardioid, I like that mic but it would be hard to mount it on-camera due to its size and weight.

Thanks once again Jay for you advice.

Well I did a few tests with changing the dBu settings and I think it did make a difference but still clipping.
I also think my problem is that I have the audio settings set at auto. (AGC)

I know its best to avoid this setting but I cannot work with it in manual, Its just to risky for me as I work alone.

I'm happy with the sound my mic picks up.. its just the occasional clipping that I could do without.

UPDATE:

Did a few tests with the sound on manual @ number 10 and this time no clipping.
But I wouldn't chance going manual at a wedding.
Any advice.

The EX3 makes very good sound recordings.
Switch of auto of course.
Switch off any noise reduction/wind reduction filter settings.
Gain on about 6 with a properly set up mixer .
Or stick the mic straight in and test by checking levels and avoiding hitting the top of the scale by keeping the gain down low enough.

Obviously test it all extensively at home in the week before the event.

I don't understand why you say you wouldn't risk going manual at a wedding when the actual high risk option is using automatic. If you're afraid your levels will be too low on some passages when you use manual, remember you can raise them in post but if auto recording gain results in clipping there's nothing you can do to fix it later, nor can you fix the 'hunting', where the gain raises to max on its own during a quiet episode and then has to clamp down when the subject volume comes up, leading to 'pumping' of the background ambience, after the fact.

Thanks Steve for the advice.

Its not so much that it would record the levels lo low... its more recording it too high that I'm afraid of.

Thanks Jimmy.

I might try that at my next wedding.