K-click (relay mod vs brise)

[TomB]

In a pre commute tinker this morning, I removed the FIA key and long runs of red cable from the equation and directly attached the battery to the starter with a short length of heavy cable cable. Resulted in lots of cranking, with each press of the button. Got through several presses with cranking until the battery dropped to 12.5v and the click returned.

 

This was much improved and points towards loss on the FIA key or long run of cables. The long red cables were replaced with cable supplied from Redline, along with the key last year. So I guess either the cables or key have high resistance, the switch is wired wrongly or some other loss is occurring. Maybe the red cables are not heavy duty enough and I'm loosing current through them. However, given that the cables I fitted last year are 25mm2 and ~10mm OD, which according to CBS website are good for 175amp, this seems unlikely.

 

 

Edited by - TomB on 13 Nov 2013 21:37:22

[TomB]

When the red cables are joined together to bypass the key, with the remaining of the FIA wires & key left in situ, I still get a click from the solenoid and no cranking. Suggests to me that its not the FIA key offering resistance - also when resistance is measure, there is no significant reading on the multi-meter.

 

Do I need red cables sufficient to jump an aircraft carrier? Next Ill double up the cables.

[TomB]

Bit of update, if anyone is interested.

 

Ive fitted a new engine/ chassis earth, this time its directly attached to a spare drilling on the block to avoid going through the engine mount & dry sump cradle. Starter/battery earth cleaned, under dash earth cleaned. FIA key earth to skin all cleaned - here was a bit of ali oxide on the skin so thats been rubbed off.

 

When the battery was reading 12.8v, the white/red wire from the starter to the new relay read 12.63v at the spade connector each time the button was pressed, so plenty to trigger the relay. Relay switching nicely.

 

When fully charged, the battery read 13.1v, which is realised at the FIA key on both big red contacts.

 

The starter motor spins well on first press of the button, but not consistently on any subsequent presses, so still not reliable. When there is no turn over, the voltage drops at the battery a couple of volts when the button is pressed, then the battery voltage recovers to a touch less from where it was, say down 0.3v.

 

Im yet to double up the starter cables to see if I have loss along that circuit, but the voltage readings don't suggest it. I will also look at the solenoid to see if the lever is correctly engaged and its all clean in there, while the starter is off I'll inspect the ring gear. Someone has suggested I could have lost teeth or the starter gear isn't engaging.

 

 

 

 

[Roger Ford]

Quoting TomB: 

FIA key earth to skin all cleaned - here was a bit of ali oxide on the skin so thats been rubbed off.

That's nothing to do with the starter circuit - the earth (via the resistor) is just to dump current from the alternator if you turn the key off with the engine running.

 

It does rather sound like the starter itself is faulty here.

[TomB]

I was wondering about whether its a fault with the starter on the tram this morning. Im thinking along the lines that there is enough shove for the solenoid to engage first time, but does it return to its home position for the next press of the button? I know there is a copper plunger, big spring and lever in there, but not much beyond that. Can anyone explain how it works, and whether the lever should be hooked into the plunger arrangements?

 

I have a spare starter to swop over which could be the next step.

[Bricol]

I'd do the swop next fettling time.

 

I had similar with a Pug 106 - would work sometimes, then click . . . normally when the thing stalled on it's own in traffic. Removed, checked, cleaned, bench tested starter and it was fine. Back in the car . . . useless.

 

Different starter ( I won't say new as it was a fiver from ebay) and it's been starting reliably everytime for several years.

 

Bri

 

(stalling in traffic evenutally traced to a just about blocked, new, air filter, in-case you were worried ;-) )

[TomB]

Latest update - its a faulty solenoid! Swopped spare (old) starter and it cranked happily on every press of the button. Swop solenoid over and Ive managed to pin it down to a failing solenoid. So thats definite progress. If replaced the exciter cable with a nice fat 27amp brown cable.

 

Now the next problem to cure - regular melting of the cable due to the proximity of the primaries on my 4-1 exhaust as shown in this photo.

 

The exciter cable is barely <5mm from the primary - with some heat insulations (foil matt type) it will be virtually touching. As I see it, the most sensible and long term solution is to move the solenoid under the starter i.e. fit a later Magentron or Brise starter.

 

Has anyone ever done this on an older K Series?

 

Are there any other options? I wondered whether I could fit an alloy plate, with appropriate holes formed to match the exhaust ports and mounting holes, to the block to move the exhaust out by, say 8mm.

 

 

 

[Titanium7]

Tom

Fabricated a 22swg aluminium shield to protect my alternator which is held by being bolted to the No.1 primary bolt. Seems to have protected the alternator from undue heat.

 

My starter is quite away from the primary (bespoke Powerspeed) so didn't feel that it needed a heat shield.

[TomB]

Ive borrowed a Magnetron starter, it fits on the engine, cables all reach and it turns. However, it doesn't engage with the flywheel, and the starter just spins. The Magetron, as shown here, doesn't appear to have much length of gearing protruding from the starter, so Im wondering if its the wrong flywheel/ starter combo. Could the way the starter is electrically connected affect whether the gearing exits the starter and meet the flywheel?

 

I assumed all the starters for the K series where compatible with the flywheel/ bellhousing, but is this not the case?

[Stationary M25 Traveller]

Might be a silly question ...... when you say it just spins ..... did you connect the supply just to the starter motor switched terminal ...... or did you connect 12V to the normal terminal and also use a 12V supply to the spade terminal which energises the solenoid and throws the gear outwards so it engages with the flywheel ring gear ?

 

Edit ..... hard to tell from the photo .... but is the motor concentric in the mounting plate, or could it be possible to mount it so the gear wouldn't mesh ?

 

Edited by - SM25T on 23 Dec 2013 08:16:12

[TomB]

I'm not too familiar with the Magnetron, but I think I got the connections right as I replicated them on the floor with a spare battery and the gear was flung out turning rather quickly! There are two thread copper terminals on the solenoid: one with a plastic cap and the copper connections from solenoid to starter which doesn't look like its ever been apart; and the other, to which I connected the big red cable, and other power feed cables (eg light feed).

 

I will try again when Ive located some threaded M8 bar/ cut down a long bolt and mounted it with the three attachments rather than the two, as it might not have been making proper contact with the ring gear.

[Stationary M25 Traveller]

That sounds feasible. Do let us know how it goes.

[Stationary M25 Traveller]

What did you find on the above ?

[TomB]

I found that the Magneton starter is quite sensitive to being properly bolted! I fitted some threaded bar and refitted it and it span the engine perfectly. So that's the answer, will fit one once I've paid for Christmas! I've been offered a used one, but am tempted to buy a new one as I don't want to take it all off again if the solenoid on a used one causes trouble.

 

[SLR No.77]

Quoting TomB: 

I found that the Magneton starter is quite sensitive to being properly bolted!

You "might" need just a touch more grinding off the block, it's possible the starter isn't locating perfectly.

 

Stu.