Yamaha SR 125 Struggles to Start

GrafVonJon · Derestricted Danger Joined: 21 Jul 2011 Karma :

Hi All,

Had a Yamaha SR 125 for about three weeks now. It's never started properly using the electric start, which I put down to a a poor battery (which also doesn't hold it's charge). The starter motor turns the engine for maybe a second, before loosing charge and just emitting a clicking/buzzing sound.

Not been a problem so far as I bump start the bike. It starts perfectly every time as soon as I let the clutch out in 2nd.

Until last night. I ran out of road in my village bumping it before it started.

The engine seems to turn, and sounds like there's ignition (IE sounds like it's ticking over) but this sound only lasts for as long as i can push the bike in gear. Once I stop and bring the clutch back in the engine stops.

I've kept the fuel tap off, when not using the bike.
I've had the fuel tap on when bumping.
The choke was fully out (when it eventually bumped, it struggled for a few seconds and then got really 'revvy' as the choke kicked in, but it took a while).
There was a gap between riding last and trying to start again of 2 days.

Does it sound like an issue somewhere in the fuel delivery? blocked lines? filter? etc.?

Every now and then (twice in last 3 weeks) the bike has not responded instantly to throttle input, but taken a couple a seconds between twisting the grip and the engine picking up revs. This only lasts for a few minutes and then everything seems OK again. Last time the bike started doing this it actually cut out. Then I couldn't get the bike started again for a couple of mins.

When it did start again, it ran flawlessly for the next 200 miles or so, but still needed bumping to get started the following few mornings - though these bump starts were instant, with the engine firing and running the first time the clutch was let out.

jjdugen · World Chat Champion Joined: 03 Jun 2011 Karma :

For Gods sakes, its been telling you it needs a new battery since you have had it. Do without a bag of skunk for a night and damn well buy one.

GrafVonJon · Derestricted Danger Joined: 21 Jul 2011 Karma :

The battery is actually new, and newly fitted by the garage when I bought the bike.

I don't think it has properly conditioned/charged, as it's only source of charging has been when the bike is running.

I'm waiting for a friend to bring a charger round to leave it on charge for a couple of days and see if that helps, but does this explain why it wouldn't fire when bumped?

I Appreciate that I'm new to this and these may be obvious questions, so bear with me.