refusing to start

Message

D-Rider · #16 Post by **D-Rider** » Tue Mar 10, 2015 5:06 pm

mrapriliafalco wrote:I can't see how it would work from a jump start if the relay was knackered

Depends what you mean by "knackered"

A build up of oxide on the power contacts will increase the impedance in the circuit.
If you have less internal impedance in your jump-start source, then the total impedance might be sufficiently low to let it start.
Were talking marginal situations here.

fatboy · #17 Post by **fatboy** » Tue Mar 10, 2015 7:31 pm

Think d-r is pointing you in the right direction, you need to check all pos and neg connections from battery to starter relay to starter motor. You also must check main earth to frame connection.
Any of the above that are loose or dirty can cause you the problems you're having.
Check your battery voltage after attempting to start, if it remains above 12 volts then the battery is prob OK.
If you are checking/cleaning connections don't forget to disconnect battery first !

mrapriliafalco · #18 Post by **mrapriliafalco** » Tue Mar 10, 2015 7:48 pm

Thanks Lads
Can someone explain how a 150 amp solenoid works better??? don't it need 3x the power of a 50 to do the same job

flatlander · #19 Post by **flatlander** » Tue Mar 10, 2015 9:03 pm

It just does! ;)

mrapriliafalco · #20 Post by **mrapriliafalco** » Tue Mar 10, 2015 9:15 pm

My style of answer hahahaha

D-Rider · #21 Post by **D-Rider** » Tue Mar 10, 2015 9:18 pm

Hmmm.

A 150A solenoid is overkill - though it might be better (I know that sounds strange)

A 150A solenoid can cope with 150A flowing through it for a significant (specified) period of time.
The starter motor will not draw that much current (well only for the briefest instant before it starts to spin ... and that's not an issue). A decent 50A solenoid would probably have been OK (the early bikes had 50A solenoids) a good 100A solenoid is fine (the later bikes got 100A solenoids)

What you are really after is a solenoid with low contact impedance and contacts that will not degrade too readily.

The standard relay seems to be one with poor quality contacts.

D-Rider · #22 Post by **D-Rider** » Tue Mar 10, 2015 9:20 pm

BTW although we've been looking at other parts of the starting circuit, I'm not saying the battery is necessarily OK. It is another candidate for suspicion.

mrapriliafalco · #23 Post by **mrapriliafalco** » Fri Mar 13, 2015 2:06 pm

Thanks for all the advice lads
Bought one of them yellow motorbatts and she fired up straight away
Happy days,got one for £45

D-Rider · #24 Post by **D-Rider** » Fri Mar 13, 2015 2:09 pm

mrapriliafalco wrote:Thanks for all the advice lads
Bought one of them yellow motorbatts and she fired up straight away
Happy days,got one for £45

randomsquid · #25 Post by **randomsquid** » Fri Mar 13, 2015 7:09 pm

mrapriliafalco wrote:Thanks for all the advice lads
Bought one of them yellow motorbatts and she fired up straight away
Happy days,got one for £45

I've got one ready to go on when it gets a bit warmer. I've had a couple on other bikes and rate them.