Starter... Where is the problem ???

[luk4mag]

Hi guys.  :)
I have a problem with starter motor in my Spitfire MKIV.
When I try start the engine battery is discharged very fast... after few spinnings. Also I have a feeling that engine is spinning not fast enough...
Battery is quite new. When I checked the voltage on battery the voltage was:
12,4 V before starter running and 9.0 V on first spinnings and later 6.8 V just after maybe 30 spinnings in total... After that starter can't even spin the the engine at all.
On my second battery is the same situation.
I've checked brushes and thickness is ok.

Guys do you have any idea what going on??? Solenoid or something wrong with starter???

[DougBGT6]

12.4v is not enough for a new charged battery, should be around 13.5v. Could be alternator, more likely earth strap? Have you a battery charger? Charge it up, try it again. If the same it's a bad earth strap.

[JohnD]

13.5V might be the potential measured at the battery while the engine is running, but a fully charged battery cannot hold more than 12.6V.  12.4V isn't bad, but it ain't perfect.

And as you have exhausted TWO batteries trying to get started, I think that you should look for other causes.  That it 'isn't spinning fast enough' could indicate poor connections or a poor earth and the Earth strap needs a check - do you have one?  It's often forgotten after a previous rebuild, or the manky little bit of wire braid that Triumph provided just rots away.   Fit a length of starter cable between the engine block and the battery earth point, making sure that the terminals are in contact with bare metal at each end.

Then the connections.  DO you have an OE starter?  Or a new HiTorque, preeengaged type?  The latter has a smaller cylinder on top of the motor cylinder.  Have you connected that correctly, and have you kept the OE starter solenoid? (On the bulkhead - no longer needed)
Check all connections, and if you have a multimeter, the resistance of the starter cable, across the starter solenoid when energised and between the starter body and earth (see earth cable).

Good luck!
JOhn

[Dannyb]

I had the same problem until i fitted another standard starter motor. mine was down to worn brushes.

[luk4mag]

Hi all  :)
Thanks for suggestion.

Tomorrow I will gonna check and clean all wire connection around starter motor, solenoid and battery.
By the way my starter motor is M35J Lucas so standard one.
Brushes thickness is 11 mm so perfect . But today I checked armature shaft and I realized that commutator is bit worn. I'm not really sure and maybe it's normal usage, but external edge is about 1mm higher than surfaces where brushes are touching the commutator. I will clean the gaps in commutator face and maybe this will something help because these gaps are full of black dust or something like that. When I touch by finger the commutator face I couldn't feel any gaps.

[WIMPUS]

I had problems with my starter also..
In the beginning when i started and learning to drive in the Spitfire (a good year ago) after 3 days of driving i stalled ( :B ) when i wanted to drive on my driveway ..
Wanted to re-start ... nothing !

So pushed it, in the dark checking everything, enough voltage to the starter & co..
Next day got it off and opened it up, bushes where replaces and gave it a good clean inside .. it worked again, but then suddenly not again  :-/

Back off and looked a bit better .. the windings where coming off the rotor !
It was so worn  :-/
So the starter was **** .
Mine was also the original M35J one (still got it in the shed).

The thing is, that i bought a full rebuild kit for it , then seen the rotor was so worn..  :-/

You can always use some copper grease between the connections so they don't rust/corrode  ;)

[luk4mag]

Hi  :)

I cleaned all wire connections and everything inside of starter motor. After that engine was spinning better but still battery was discharged quite fast. And after that I decided to look more carefuly about my batteries. And that was the problem. One battery was new (with warranty) another one bit older. I decided ask eurocarparts to exchange battery for new one and that was is. Now is spinning properly and battery do not discharge.

Thank's again for help. Now I have to sorted out another thing... ignition timing because I can't start the engine :) After that I have hope I will hear nice running sound :)