Jaffa, this is the part I've been wanting you to check, but the communication hasn't been working so far:

[Linked Image]

That is simply roebuck's picture of the bottom half of the air cleaner, with a red circle around the air cleaner's air intake, which is what I want you to look at. Is that rectangular passage clear and open, including the area around the engine's cooling fins? If it is blocked up somehow, either with a foreign body or some mud or grass, all is explained.

I've also been asking for pictures of the corresponding part of the top cover of the air cleaner box, to verify that it is not somehow blocking that air intake.

Thanks for posting those pictures, Rob. Hopefully we are now getting somewhere.