Hello :)
Im after some suggestions please :) I have a rescued Jrt x (not sure what the cross maybe, he looks completely smooth short legged JRT but has dilute colouring and mum looked a little like a westie x jrt) and he is currently 9 months old. I do flyball with my other dog, a lab and being a working type, seems to have just picked it up like second nature :D However my JRT being a terrier has a completely different mentality (and is not called Pickle for nothing haha). At the moment Im trying different motivators to have lots of fun as he is only young, encourage a good recall and return to me and have yet to find his 'holy grail' of reward. He does like food, but its not as high value as a ball, but then even a squeaky ball loses its appeal quickly. He will tug at home sometimes in play but not in garden where he prefers sniffing or digging a hole ;) Ive got a smooth rabbit skin on a line of webbing but hes not interested in that at all, toys on tuggies dont make his eyes sparkle either.  He has got a great recall to a dog whistle the same as my other dogs, but I cannot use that in flyball.

Ive taught him how to retrieve a ball using the clicker as he really couldnt work out what to do, but now he can retrieve the ball, he bogs off with it around the arena and shows the other dogs and it nearly got him into trouble yesterday which I cannot have. He utterly forgot about the fact that I was running off and hiding, calling him or squeaking his little ball.  I would just like to be able to produce something from my pocket and for his brain to decide that I had his favourite thing in the whole wide world.

Wouldnt be so bad, but Ive had Jrt's in the past, Pickle obviously has a bit more 'terrier independence' haha

Any suggestions as to things I could try as a reward as I really do want to make it fun for him as we are only on the most basic steps of training at the moment.

U say he likes food have u tryed diffrent types of food?

Have they tryed only doing 1 jump and slowley building up to all 4.

With my girl after coming back over the jumps (or missing some when she was lurning) she would run around like a numpty and I'd have to try to catch her. But then it hit me that I was taking her ball straight off her (so not to cause an problem with other dogs or her to break the ball) so seeing it from her point of view of course she didn't want to come back as she knew she was going to lose the ball she just worked for. So I stopped taking it and let her habe it for a little bit after I've put her lead back on. Now she doesn't normaly run off with it. It took a few goes for her to see I wasn't going to take it.

Another owner has a second ball she waves and drops in frount of hers so he stops trying to pick up both then she can grab him. Another has a ball on a rope. One owner used cheese and chive spread for her dog.

What about a braided fleece tuggy?  A lot of dogs that aren't massively interested in tuggies will really go for one of those, and they're very easy to make yourself.

Otherwise would it be possible to have him on a longline, just while you work through this?  Bit awkward with jumps I know but it would help reinforce that he can't be running off to do what he likes.

Just one other thought - moot I expect but just in case - I assume he's not doing the flyball box proper, full speed or all jumps at this stage?  At only 9 months old he's still developing and flyball being a high impact sport, would be too much for his joints right now I think.  Classes should be focusing on self control exercises at this stage so really, the trainer should be helping you with the attention problems.