Hi All, Ok I've decided to start a thread about the problems I've been having with my Yamaha YZF R125 (2010) to hopefully help those who have similar/same issues with their R125's and also ask for help if anyone knows anything. I've spent quite a few hours looking into the problems on the net and the only consistent issues seems to be the Fuel Pump but before that this is how things went; When I first checked her out she looked great and pretty well taken care of. I had asked the owner to cold start it when we got there and she didn't have any problems at all. I then rode her about 40-50 minutes home from the city without any issues at all and managed to stall her right in my driveway (I hadn't ridden in years except for my pre-learners and my driveway is made up of a mix of gravel, dirt, grass, a great ditch and concrete). And thus began the problems... since that point she's had trouble starting. Now from experience with my past bikes and what I know about cars I did the following; 1. I recharged the original battery first - started the first time then wouldn't start 2. Then changed it for a whole new one - started and thought it was fine. Then it wouldn't start. 3. Changed the spark plug - fired up first go - thought the problem was solved but the next day it was gone again. 4. I've ridden to work and back thinking it was fine but this doesn't seem to be the case. Now it's been about 10 days since I've had her and I'm starting to notice that there is a certain noise she makes when I turn the key to 'ON' and activate the kill switch. It's a whirring type of sound and I've read that this is her priming the fuel? Anyways I'm noticing this sound isn't always happening and most of the time when it doesn't happen she doesn't start and when she does she Cranks, Turns over and then attempts to idle but always dies out. A few times I've been able to save her with some revs but it usually ends up dying. What I've also noticed now is that during the day when I wake up (around 12-1pm) she cranks, turns over then dies. At night after work (230-3am) she cranks, starts and idles fine (the whirring sound is present). I've got a $50 fuel pump on order from ebay because Trooper Lu's quote me $600 and a mobile mechanic $650 to get the fuel pump replaced. Given that the price is quite high and the problem isn't even correctly diagnosed yet I decided my money was better spent learning more about my bike. Sorry I know it's a lot to read but I'm just wondering is it likely the temperature is the main thing affecting it's ability to start at 3am and not start at 12pm? It has gotten quite hot in and around the area lately. Today as the sun went down (around 6pm) she cranked and spluttered but wouldn't idle properly when all day she wouldn't even start. At 11pm when I gave it another shot she spluttered into life without any issue.