Hi...ive just got the tank filter and it seems a bit square....is there a right way to fit this as i know i have to remove tank filler and "sew"it on but is that it ?

Just spotted theses myself few thing that comes to mind

1.If you get the one that fits to the bike how easy is it to remove if needed looks quite a tight fit, is there a chance of it splitting then the contaminants will then get in the fuel system

2. Has anyone used the smaller universal version that does not get fitted to the bike the fuel nozzle just fits in it like a sock

https://www.guglatech.com/en/prodott...els-a00006-00/

They are very durable, and unless you are very unlucky to fill with particularly polluted fuel they can remain in place for a long time.
I have a Mazinga over my fuel pump, a neck filler ( fixed to fit under the filler neck ) and also carry the sock version to use on my auxiliary Rade tank ( KTM690 ), I can also use it on my Tenere 1200.

Just fill more slowly

Definitely a great product and potentially saving a ton of bucks if you do a fuel pump because of crud getting in. The complaint I do have is their postage is a complete rip off. For what is basically a sock I was charged at the same price that I paid for 7kg+ of suspension parts.

I have seen the sock one that's the universal filter I think???

Yes, they're made of slightly thicker material so that they can be used every time you fill instead of having one ( or two ) fixed in place on the filler and pump.

Update: I've now had the time to try and fit the "Mazinga" pump cover filter and have some experience to share.

First, as another contributor commented, it doesn't fit. When you add the thickness of the filter to the pump it is too large to go through the (quite close tolerance) hole in the tank. You get so far and the filter just jams and concertinas up, and there is no way it will go any further. Both a KTM dealer and myself have tried this now and we came to the same conclusion. I suppose it would be possible to dremel or scrape out the hole in the tank, but I didn't want to do this - the surface of the tank needs to be perfectly flat an undamaged for the pump to seat on, so any damage or excessive enlargement of the hole and fuel will leak past the seal. With replacement tanks costing over £1,000 this was not something I'm willing to risk.

Second, having looked closely at the pump I believe this filter gives no benefit, in fact it could make the blockage risk worse. Despite being a large surface area of excellent filtration material there is no point in covering the entire pump. The fuel inlet is a small hole about 4mm diameter right at the base of the pump sidewall, so the only part of the filter that is doing anything is the small section of gauze covering that hole. If there is dirt in the tank that part of the filter will block long before the inbuilt filter in the pump, starving it and causing all the burnout problems we want to avoid.

In summary, the tank neck filter works, albeit with disadvantages, but the pump sock filter is a waste of money.

This is just my experience, if anyone would like a 790/890 pump sock filter ("Mazinga") it's yours for £30 (half price), never fitted or used