Caterham starter. This ones odd!

[Rockets7]

Caterham 7 type 9 gearbox

Key in, switch on, fuel primes to carbs. With clutch up it turns over and starts sweet as a nut. With clutch down it has intermittent cranking speeds whilst trying to start from barely turning to normal speed. New battery. Starter stripped and refurbed. All earth leads checked, checked again and replaced. No immobiliser. Starter contacts are spotless. Battery contacts spotless. Positive cables are all without issue. What, why and any suggestions please?

[LarJammer]

crazy suggestion number 1: too much crank end float?

[Auntieroll]

Clutch release bearing breaking up or over long clutch pedal travel?

[Rockets7]

Good points, little more detail... Has had a new engine in this year (upgrade). Problem remains, exactly the same. Clutch bearing was changed at time.

[Happy Jim]

Rockets7 said:

Good points, little more detail... Has had a new engine in this year (upgrade). Problem remains, exactly the same. Clutch bearing was changed at time.

Slave over-extending and shoving the clutch plate into the flywheel?

[paintman]

Input shaft binding in the spigot bearing?
http://www.locostbuilders.co.uk/viewthread.php?tid...

Was it doing it before the engine was changed or was it all OK?

Edited by paintman on Friday 6th March 22:24

[Rockets7]

It's been the same for both engines. Clutch down, cranking is random speeds. Clutch up. Normal crank.

[paintman]

Are you a member of any of the Caterham clubs? Have you asked them for any suggestions? Think you're more likely to get an answer.
Reason I suggest that is that in the early 80s - before the internet - I owned a Scimitar SE5. Joining the RSSOC & getting their club magazine pointed up a number of common issues with them, one of which was known as a cause of engine bay fires which often destroyed the whole car - examining mine showed that it did have the problem & the 'how to' fixed it.

[AW10]

Can you find the "last" point in the pedal's travel where it still starts normally and correlate that to the bite point?

[buzzer]

what's the engine type? is it an inertia or pre engaged starter?

with the engine running, and someone working the clutch in and out, can you see the front pulley move in and out at all?

are there any bright marks on the flywheel ring gear on the END of the teeth on the side the starter engages?

this one has got me thinking

[andygo]

Wrong pressure plate fitted maybe?

[Rockets7]

Arggggh further update. It now does it regardless of pedal position which leads me to think starter is weakening. Crank etc and flywheel are without issue but good points.