Urg- starting issue

[stewgnu]

i took the start button apart too to see whether there was any obvious problem there.

Seemed fine, so i cleaned it thoroughly and checked the wires too.  

[Paradiso]

A 'stand by' if it won't start, gleaned from another thread on here, is a short piece of wire with a blade at each end to connect the two contacts after removing no.1 relay. I keep it under the seat. I've never been stuck, but my 2002/2003 Tenni suffers the same issue. I too have cleaned the ignition switch contacts, but it didn't seem to change the situation. I've looked at the recommendations for rejigging the ignition wiring, but haven't taken that step yet.

Sent from my SM-G925F using Tapatalk

[stewgnu]

1 hour ago, Paradiso said:

A 'stand by' if it won't start, gleaned from another thread on here, is a short piece of wire with a blade at each end to connect the two contacts after removing no.1 relay. I keep it under the seat. I've never been stuck, but my 2002/2003 Tenni suffers the same issue. I too have cleaned the ignition switch contacts, but it didn't seem to change the situation. I've looked at the recommendations for rejigging the ignition wiring, but haven't taken that step yet.

Sent from my SM-G925F using Tapatalk
 

That 87 and 30?  

I’m fair baffled with the issue- wondering whether there’s some weak connection or stressed bit of wiring somewhere in the loom that’s been bent about too much.

[billgreenman1]

I would love to see a picture of this hack.  I'm going to start crimping and cleaning soon, but I'd love to have an emergency buffer....

[stewgnu]

Ok, i think the issue is somewhere around the wiring past the headstock.  i thought i’d cleaned out the connectors but maybe i didn’t.  If i did then there’s still a loose connection or maybe a tortured wire there- some of the loom looked very sharply bent about.  

 

There’s nowt else left to fix at this stage 😀

[Kiwi_Roy]

On 11/17/2021 at 12:19 PM, stewgnu said:

That 87 and 30?  

I’m fair baffled with the issue- wondering whether there’s some weak connection or stressed bit of wiring somewhere in the loom that’s been bent about too much.

The starter solenoid will draw at least 30 Amps while it is pulling the gear into mesh, I doubt any of the wiring is up to that, first off they start with a 15 Amp fuse then send the juice all the way to the front of the bike and through some tiny wires to the ignition switch and back, I doubt the ignition switch is rated at much more than 10 Amps and it increases in resistance with age as the grease goes hard.

When you do a Startus Interuptus fix you bypass all this wiring and the solenoid will likely draw 50 Amps and operate 5 times as fast engaging with a healthy clunk.

The fix most recommended was to feed the starter relay with a feed direct from the battery through a fuse bypassing the ignition switch, this caused a few problems for owners not familiar with wiring, Lately I have been suggesting adding an extra relay mounted near the starter, one side of the contact is fed from the large live terminal, the other contact goes to the solenoid spade terminal. The original trigger wire goes to the new relay coil while the other coil terminal is grounded.

Doing it this way the bikes loom stays original, no logic is changed.

[stewgnu]

Well, like a blind hedgehog shuffling about in a sack, I’ve finally found the light…

Problem traced to one of the two bullet connectors by the headstock.  

I got stranded far from home yesterday and after checking over all the usual suspects I poked a finger down the front of the tank to wiggle the cables and boom baby!  Repeated and got the same result- had to start the bike a few times during the journey and it worked every time, fired up strong and instantly.

At this stage I haven’t had the tank off for a closer look so I can’t say whether it’s the black or grey, or both, wires that’s causing the problem.  But I’m going to cut and replace with spades when I do.

So, long story short: It was a knackered starter and bad bullets.

But I’ve been thru everything and so the starter system should be 👍 from now on 😀

[Kiwi_Roy]

 

That was a lucky find, I remember Docc telling us about that years ago.

The two bullet connectors (60) connected to the clutch switch (17), I think that's a common fault. Also on high milage bikes the wires work harden and snap under the insulation where they constantly bend back and forth around the headstock, you can find the broken ones by pulling hard on them one at a time, if they stretch the copper core is broken.

 

[Chuck]

Quote

Problem traced to one of the two bullet connectors by the headstock.  

Hmmm. I thought I mentioned that earlier in the thread. Maybe it was on another post? I've seen that one first hand.

[stewgnu]

yes i checked them twice previously as i was going thru it, but didn’t identify the problem, missed it.

i was doing the old yank all the cables routine and that did it

[stewgnu]

5 hours ago, Kiwi_Roy said:

 

That was a lucky find, I remember Docc telling us about that years ago.

The two bullet connectors (60) connected to the clutch switch (17), I think that's a common fault. Also on high milage bikes the wires work harden and snap under the insulation where they constantly bend back and forth around the headstock, you can find the broken ones by pulling hard on them one at a time, if they stretch the copper core is broken.

 

i’d kind’ve ignored the clutch safety as i’d assumed the po had bypassed it, rookie error i spose

[Kiwi_Roy]

If you carry under the seat a jumper cable about 3 ft long with a spade connector on one end and a bare wire at the other you can always slip it on the solenoid and touch the battery positive with the other. This will send 50 Amps to the solenoid and the starter will engage and spin.

Just be careful to make sure the bike is in Neutral and pull the clutch for good measure.

As well as starting the bike this jumper proves that the battery and starter are ok but of course if the battery is flat, disconnected or the starter is toast nothing will happen. I always found my VII Sport easy to bump start in 2nd gear.

[Kiwi_Roy]

Applying a "Startus Interuptus" fix to a VII is a bit tricky, its not as simple as providing the start relay 30 terminal with a direct feed from the battery because the start relays 87A (normally closed contact) feeds the headlight relay. if you provide a direct feed to the 30 terminal the lights will come on when the key is Off.

Heres a simple way around that using an additional relay. I call a booster relay.

The relay coil is driven from the original solenoid trigger wire which now only has to provide a fraction of an Amp

The new relay's contact is fed from the large positive terminal on the solenoid via a 20 Amp in-line fuse, the other contact feeds up to 60 Amps to the solenoid ensuring it will throw the gear into mesh faster than its ever done before.

Its not the only way to boost the starting, you can run 12 Volts to the existing start relay and make other arrangements for the headlight relay, I just put this forward as a simple way of fixing a problem without chopping into the OEM wiring.

The first thing to do is test for Voltage at the start relay 30 terminal with the key turned Off,  if its present that's the earlier wiring bypassing the ignition switch.

If the Voltage is only present with the key turned On thats the later wiring i consider to be weak as its throttled by the switch and extra wiring to and fro.

 

The wiring at the top of the sketch is the OEM start relay, I only show the contact and don't show where the 12 Volt supply comes from.

The wiring in Red is new.  If you use an old Bosch relay with mounting tab you don't need a base, just use individual spade connectors.

 

Re the solenoid, I thought an explanation might be helpful.

I show both the coils in the solenoid side by side, each coil has about 300 turns of wire, they are actually one inside the other. The heavy one I call the Grunt coil because it does most of the work engaging the starter is wound on first, the light one I call the Holding coil is wound over the top.

The coils are quite different in resistance, the Grunt coil is only 0.25 Ohms and the Holding coil is 1.25 Ohms so by simple Ohms Law you can calculate the current they draw. Grunt 12 V/0.25 Ohms  = 48 Amps, Holding 12 V/1.25 Ohms = 9.6 Amps

The magnetic strength of an electromagnet is the product of current x the number of turns. Grunt 48 x 300 = 14,400 Amp turns, Holding 9.6 x 300 = 2,880 Amp turns so you can see the Grunt coil is magnetically 5 times as strong as the Holding coil.

Note how when the main contacts close the Grunt coil has +12 Volts on both ends, so the current in it drops to zero leaving just the Holding coil to keep the starter engaged. The time it takes for the solenoid to engage the starter gear is quite short, between 15 and 100 milliseconds all depending on how much current you can cram into the coils which is of course dependant on the resistance between the battery and the coils.

If all this has made your eyes glaze over its just the half of it

 

[Paradiso]

Thanks for posting that Kiwi_Roy.  I've read most of the other posts about Startus Interruptus, yours and others', but still wasn't quite clear about how to proceed.  It's clear that there are a few different approaches-being a complete electrical dunderhead I found it a bit confusing.  The combination of the drawing and the summary really helps. 

I like the idea of limited chopping into the original loom too, so it's reversible if I mess it up.  I also like taking the new positive from the starter rather than the battery, which already has quite a few ring connectors attached.  

When you write, "The first thing to do is test for Voltage at the start relay 30 terminal with the key turned Off,  if its present that's good", I'm not quite sure what you mean.   

Do you mean that this check on the original starter relay verifies that you have the 'weak' wiring which routes the solenoid trigger through the ignition switch?    Or do you simply mean check this on the newly wired relay to ensure all is good?

I have a V11 Tenni registered in 2003.  It occasionally suffers from 'Startus Interruptus'.  In the past I've removed the starter relay and connected contacts 30 and 87 on the starter relay base with a length of wire to start. 

Is there a  simple test to check that my bike has the 'weak' wiring system?

Thanks

[Kiwi_Roy]

3 hours ago, Paradiso said:

Thanks for posting that Kiwi_Roy.  I've read most of the other posts about Startus Interruptus, yours and others', but still wasn't quite clear about how to proceed.  It's clear that there are a few different approaches-being a complete electrical dunderhead I found it a bit confusing.  The combination of the drawing and the summary really helps. 

I like the idea of limited chopping into the original loom too, so it's reversible if I mess it up.  I also like taking the new positive from the starter rather than the battery, which already has quite a few ring connectors attached.  

When you write, "The first thing to do is test for Voltage at the start relay 30 terminal with the key turned Off,  if its present that's good", I'm not quite sure what you mean.   

Do you mean that this check on the original starter relay verifies that you have the 'weak' wiring which routes the solenoid trigger through the ignition switch?    Or do you simply mean check this on the newly wired relay to ensure all is good?  Yes, that's exactly what I meant I will revise my wording to be more clear  

I have a V11 Tenni registered in 2003.  It occasionally suffers from 'Startus Interruptus'.  In the past I've removed the starter relay and connected contacts 30 and 87 on the starter relay base with a length of wire to start.  

Is there a  simple test to check that my bike has the 'weak' wiring system? Yes probe the 30 contact for voltage with the key off

Thanks

Thanks for your response, I went back and revised my wording a little hopefully its clearer  Yes we are looking to find out what version of the wiring you have, I used to think the early ones all had a direct feed to the start relay but now I'm not so sure.

Really it doesn't matter with the added relay how weak the original wiring is.

If you have the wiring with always alive pin 30 you should be able to make it work. The wire from the relay to the solenoid is too small on most guzzles 

PM sent.