Ducati monster 620ie loss of power..

[SpikeC]

Yup.
Although it does sound like a loose wire based on the onset description.

[mr.freezer]

but loose wire where??? wires to coil or to injector??

[Ledz558]

I got the same bike with the same problem. I changed fuel filter about 3 months ago, added some air to my rear tire, which helped. I come to the conclusion that its the throttle body setting, as well as a 3 year old battery, main chain adjustment. I was going to  adjust my chain, put a new battery in and try another set of coils.
I've been trying to figure this out now for months. Sometimes it seems like I have low compression, I have major oil mist around the top of engine. And sometimes  my bike when I start it will make  this weird noise reminding me of the starter motor grinding. When I turn the key and the engine starts to turn there's this noise that sounds like something is over running, it's real hard to explain. I get a backfire pop from under the tank on occasion.  There's 27K on the engine.  Any suggestions would be helpful.  

[SpikeC]

but loose wire where??? wires to coil or to injector??

Could be either. Or not. It is just that the sudden onset sounds like something just vibrated loose somewhere. It happens as the miles pile up.

[mr.freezer]

what about damaged valves??? I have heard that sport Exhaust can cause that..

[ducpainter]

what about damaged valves??? I have heard that sport Exhaust can cause that..

A leak down test will determine if there is an engine problem.

[mr.freezer]

I've just swapped injector and suddenly the horizontal cylinder does the problem... so there will be problem with injector...

Is it repairable or is needed to buy new one???

[Slide Panda]

It's possible the injector is stuck. They can be cleaned - though DIY cleaning is probably not worth the effort as equipped shops (in the us) charge between $12 and $15 per injector - and they will have better gear than any home cleaning set up as well as a flow test machine.

So have them cleaned - be sure to mark the trouble one in some way and bring it to the attention of the shop. if cleaning/pro service will not suffice then you will probably have to buy a new injector set

[mr.freezer]

do I have to buy whole set or just one injector??

[DarkMonster620]

do I have to buy whole set or just one injector??

Usually it is best to purchase both, if you are in the US  or not, contact Chris @ ca-cycleworks, he is a forum sponsor , and he will sell you a "match flow set" of injectors

[mr.freezer]

I am from slovakia... I can buy one injector from crashe M620... I put my injector to brake cleaner... maybe it will help... ... how to clean it at home??? can it be dismount somehow??

[SpikeC]

 You could run some Techron though the system. i worked for me!
Butt then again, it sounds like the wiring to the injector. you need to check the spray pattern from the injector before replacing parts.

[Howie]

You won't clean it at home.  If fuel goes through the injector at all Techron is worth a try, follow directions, to strong is no good.  http://www.chevronwithtechron.com/products/fuel-additives.aspx  no idea of availability where you live. 

You could run some Techron though the system. i worked for me!
Butt then again, it sounds like the wiring to the injector. you need to check the spray pattern from the injector before replacing parts.

Since injectors were swapped wiring is eliminated.

[JamesBill]

I just bought two new injectors from CA cycle works. The reason was I bought a bike that had sat for many years and the fuel rail that sits on top of the injector was totally corroded.

If you want my old injectors, you can have them. I KNOW one of them works, but the other was blocked from working. I live in Texas though so it might just be better to get yours cleaned than ship them from here.

[DarkMonster620]

You could run some Techron though the system. i worked for me!
Butt then again, it sounds like the wiring to the injector. you need to check the spray pattern from the injector before replacing parts.

You won't clean it at home.  If fuel goes through the injector at all Techron is worth a try, follow directions, to strong is no good.  http://www.chevronwithtechron.com/products/fuel-additives.aspx  no idea of availability where you live. 

Since injectors were swapped wiring is eliminated.

No Techron in Slovakia, maybe this, https://www.motul.com/sv/en/products/98?f%5Bapplication%5D=143&f%5Brange%5D=21