2.25 petrol not running well

[Wittsend]

I didn't think the 25D and 45D rotor arms were interchangeable.


I'm hampered as I've never had/dealt with a 45D dizzy 

So, we need a bit of clarification here.

Either way you don't need a rotor arm with the fixing rivet 

[Alan Drover]

If necessary I can photograph the 45D4 fitted to my Land Rover but both my Land Rover and MGB GT have them and I can assure you that the red rotor arm on the left in your photo is the correct one. I'm surprised that rotor arm in the photo of the distributor ever worked.
If a genuine Red Rotor is fitted it may solve the problem but that one with the rivet has to go.
The 2.5  45D4 was originally fitted with the later sliding points identifiable by the blue plastic on the points as opposed to the red of the earlier ones.

[alex1987]

Would the easiest thing for me to do to get a 25D from the distributor doctor? As I said I am a novice with these so I am a bit confused 

[Wittsend]

I'd say not at this stage. A good working Lucas 45D should give reliable service. Try a new (red) rotor arm. Check all the wiring - coil to dizzy and have a look at the spark plugs.
What colour are the electrodes
Get them gapped to 38/40" thou, as you have electronic ignition.
Are they NGK BP6ES plugs ?



What are the HT leads like - they are a service item, get some heavy duty silicon leads from PowerSpark 

[diffwhine]

No. What you have seems more than adequate. What you could do is let the Distributor Doctor give your one the once over, but that would take time and cost...

The correct rotor arm for the 45D distributor is part number RTC3614. It looks similar to the earlier one RTC3612, but the visible difference is in the shape of the rotor arm contact head. RTC3612 has a hooked tip while RTC3614 has a more of a symmetrical head. Your one appears to be the correct arm for a 45D distributor.

It is true that there is the ability to tweak things a bit more accurately with a 25D or earlier DM2 distributor with a vernier adjuster, but it was ditched in about 1974 on Series 3 models and replaced with the simpler (read cheaper) Lucas 45D which is what most Series 3 engines had. There was also a Ducellier distributor option fitted as an alternative. That one is easily spotted having an externally mounted condenser.

Pop a new quality RTC3614 and see how it goes. Note that having a rivet fitted is not necessarily an issue. The problem relates to the rivet integrity. There are loads of vehicles running about with rotor arms with rivets and I think several of the old stock genuine Lucas ones I have appear to be rivetted. I'm not going to ditch them, because they aren't faulty. Its the cheaper copies which can be an issue.

I have at least one whole new old stock Lucas 45D (with points fitted) if you do decide to replace the distributor, but getting the Distributor Doctor to rebuild one is a big expense.

[Alan Drover]

Provided the internals are working keep it.  Do the check that I mentioned in a previous post for the bobweight springs.  If that's ok then keep it. Don't forget the occasional drop of oil through the baseplate to lubricate the bobweights.
However I must disagree that the rotor arm in alex1987's photo is the correct one for a 45D4.. I'll photograph mine tomorrow. With the 45D4 the rotor arm is the same irrespective of whether sliding or fixed points are fitted.

[Alan Drover]

RTC3612 was fitted to the 25D4 distributor on the early Series 3 engines up to suffix C when the 45D4 was fitted to suffix D onwards and the rotor arm was RTC3614 according to my Series 3 parts list.
RTC3614 was fitted also to the 2.5 sliding points distributor on the 2.5 petrol engine 90/110 according to my parts list for that particular Land Rover.

[alex1987]

Thank you so much to all of you for your advice.
I will check the plugs, get a new decent rotor arm and have a good clean up and some new HT leads.
Will let you know the outcome as and when I get it sorted.

Out of curiosity, how did you all gain so much knowledge on these?! Just through land rovers as a hobby or as a job? I know land rover mechanics but knowledge of the older vehicles is scarce.

[Alan Drover]

For my part I'm self taught as whatever vehicle I own or have owned I learn as much about it as possible.

[Wittsend]

Nearly 60 years playing with (old) cars ... lots of expensive mistakes and bruised knuckles along the way.
Some stuff you can't read in books, you have to live it.

 

[Alan Drover]

I always had a keen interest in vehicles way back as a child (yes I was one once) and just carried on from there. I never had any formal training, just picked it up as I went along.

[diffwhine]

Provided the internals are working keep it.  Do the check that I mentioned in a previous post for the bobweight springs.  If that's ok then keep it. Don't forget the occasional drop of oil through the baseplate to lubricate the bobweights.
However I must disagree that the rotor arm in alex1987's photo is the correct one for a 45D4.. I'll photograph mine tomorrow. With the 45D4 the rotor arm is the same irrespective of whether sliding or fixed points are fitted.

Are you sure on rotor arms?
I've just googled images of RTC3614 and they all look very similar to the OP's image.

Here's an example:
https://www.johnrichardssurplus.co.uk/rotor-arm-rtc3614.html

[geoff]

By the way don't buy one of these from Holden  !!!   https://www.holden.co.uk/p/45d4_45d6_rotor_arm

[Alan Drover]

I had a closer look at the image at post #12 and it looks longer to me than the correct rotor arm but after a thorough examination I came to the conclusion that it was the angle of the photo that gave me that impression.
Apologies to all. Brain fade session now over.
I'm now in the naughty corner wearing a conical hat with "D" on it.

[diffwhine]

Scary pricing for such a cheap service item. Makes you wonder about their other charges.