20 replies to this topic

[IronmanG]

What cca battery are you running in your mini. Mine is 330cca and is really struggling to turn it over.

[Cooperman]

Mine are both 510 CCA and work fine even with the 11:1 cr on the S.

[IronmanG]

Cheers. Ye we had to put a booster pack on it to get it to crank.
If everyone is using 400 or so plus then that would seem the obvious problem. Earthing seems ok

[timmy850]

My old one was 260CCA and it worked fine

I swapped to a bigger 560CCA battery when the first one died, mainly as it filled up the battery box a bit better

[cal844]

I use a Yuasa 063 size battery with 425CCA, it'll crank my 998 or 1275 into life even after 3 months of hibernation

[beardylondon]

Use the same 063 size, many many years ago I was told it was the best fit for the size hole and was apparently the same as the metro, could be wrong!

I use a Yuasa 063 size battery with 425CCA, it'll crank my 998 or 1275 into life even after 3 months of hibernation

[GraemeC]

So many factors will affect this - temperature, cc, compression ratio, cam, condition of solenoid, condition of cables and connections........

330cca should turn even a tuned engine over just fine, so I suspect the problem is elsewhere, either failing battery or poor connections.

[IronmanG]

I was surprised. Its a new battery and been kept on the charger

Compression 10.1
Everything else is new. I will try a second earth strap possibly and clean the connections again

[floormanager]

What cca battery are you running in your mini. Mine is 330cca and is really struggling to turn it over.

Don't discount a dodgy starter.  I had one of them, would barely crank.  Changed it and it flew around

[IronmanG]

Ye we took it off and connected a battery across it. Spun up ok but that's not to say its spot on. Can try new brushes give it a clean firat

[IronmanG]

I've tested from the battery to various points on the engine and body and I'm getting 0.3 ohms resistance. Its consistent between both so that rules out earthing unless anyone thinks that's a bit high?

[GraemeC]

Doesn't really mean anything as poor connections can show low resistance, but then break down under load.

Likewise a starter spinning on the bench doesn't mean it won't be lazy once you ask it to do some work.

[KTS]

..what voltage are you seeing on the starter terminal when cranking, and how does that compare to the voltage on the battery post when cranking. 

 

losses in the connection between battery and starter will show as a voltage drop between the two when under load

[IronmanG]

Will check that Pat, cheers

[floormanager]

Doesn't really mean anything as poor connections can show low resistance, but then break down under load.

Likewise a starter spinning on the bench doesn't mean it won't be lazy once you ask it to do some work.

Same with mine,  New brushes, bushes, new bendix but would take high current and barely turn the engine.  Changed the starter - spun over like a nutter!