YBR 125 shenanigans.

[Bogart61]

I'm hoping the brain trust and experience here will be able to help. I've got a 09 plate YBR which ended up sitting in the garage unused for 8 months or so. The fuel pump had gone when I came to try and get it running again, so got an eBay replacement and swapped it. Put a new battery in and then swapped out the old fuel, which was a pretty awful deep orange.
I can get the bike started but it will often start then drop revs and stall. A couple of goes of this and it'll keep running for a couple of minutes and do the same thing if left. If I try and Rev the engine it will tend to make a sort of coughing/popping type noise and then drop or cut out. If I keep this up it warms up and will tend to stay running. However, if I open the throttle it revs unevenly, tending to stop at about 3000rpm. With the throttle open the pitch of the engine drops but it doesn't want to rev past this.
I appreciate diagnosing things like this is pretty tricky but any thoughts on the matter would be appreciated. I'm keen to get the bike running reliably so I can practice a bit before I do my full sized bike test and then sell it to go towards the first bike. At the moment it has "limited" value...

Cheers, Chris

[Rogerborg]

My internets diagnosis is a gummed up injector.

Further webwisdom suggests that you'll want to get the injector out and pulse an appropriate amount of voltage (which might not be 12v) into it to actuate it while spraying cleaner through.

I also play a doctor online if you'd like a virtual prostate exam. The process is pretty similar.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[Bogart61]

Thanks for the tip, I'll try and have a look at that today.

As for the medical check that would be great. I'll send you my bank details first though so you can take your fee...