hey all, picked up my 748 yesterday, every time I got fuel on the way back when I restarted her she sounded like she really struggled to start with no real crank and then suddenly as it struggled it fired. All good. About to leave home and as I went to pull off a car came round the corner I stopped sharply and stalled the bike and now it won't start. All lights are on, fuel pump sounds good. I spoke to a local supply shop because the battery looked old and I was told a new battery might solve it as it would need a high cold cranking power. Got one and to no avail. Can anyone shed any light as I'm desperate to show the bike off Thanks
Classic issue,..........poor earthing lead. Clean all contacts particularly earth to chassis, or better still get a new bigger better earth lead made up.
I'm not mechanically minded at all, where will an earthing cable be If this resolves it I'll send you a drink
As Andy says, the earth is the thick cable that goes from the battery to the engine, clean all contact points. Steve
as said, if you are happy with battery being ok then checking all heavy duty earth/live leads is next. If you are brave you could try connecting direct using jump leads to confirm that it's the leads/solenoid at fault but you need to connect live to starter terminal very carefully as it's easy to earth out on body of starter or frame - best to connect earth lead last (there will be sparks - make sure you are in neutral obviously). Must add - if starter is churning engine slowly then don't do this repeatedly as it's the very thing that will ruin the starter sprag eventually.
Cleaned earth and still nowt, I can bump it and everything work but just no cranking, lights don't dim when I press the button etc. just confused as it sounded like it was struggling to crank over when I purchased it, never owned one so was unsure. When it fired every time I thought must be normal but now nothing.... Grrrrr
I can only repeat - first check battery is definitely ok - if new/recently charged then 99% certainty - then get some jump leads and bypass everything straight onto starter, if this churns ok then it's your leads or the solenoid and particularly now you say it's not churning at all then it can be the tiny plug that goes onto the starter solenoid which can easily lose contact as it's not a particularly tight fit or can have light corrosion on the contacts* - it's next to the battery. If the jump leads connected directly to starter don't work then (apart from battery condition) it has to be the starter playing up. *this is the 'favourite' but can also be starter switch itself and/or it's wiring/connections.
So jumping it, i basically miss out starter relay by connecting red that went into relay to wire that is bolted to bottom of starter motor?
if you haven't got any jump leads you can crudely short out the two thick-wire connections on the starter solenoid with a large flat bladed screwdriver, yes (with sparks) but this is only a 'part' test and doesn't rule out other possibly dodgy leads/connections.
it's ok - none of us have explained with much detail - by clamping a jump lead direct from battery earth to engine crankcase you are just 'doubling up' the standard earthing wires and so ruling out any possible earth connection or wire weakness problem that might exist within them.
re: post #15 - watch the heat through your fingers but if you even touch those two leads you show in your pic together then starter should churn immediately (obviously with battery connected). If you suspect your bike battery then there's nothing wrong with connecting a small-ish car battery (40-50 Ampere/hours) up as long as car engine isn't running.
it will be fine - just for testing (only and in the following order!) you could bolt those two red leads together then (with earth lead disconnected at battery) connect up live battery terminal as usual then finally with care - take the 'totally disconnected at both ends' earth lead and then connect one end to the battery as usual before finally firmly touching other end on engine crankcase - the last connection should spark slightly but if you touch it firmly it will be fine and starter should definitely churn at this point.
