I have a 1973 2000tc and I ordered a new rotor arm today from rover classics.. Anyway.. It looks nothing like the one in my car? The one on the car is or looks like your standard small rotor arm black with a brass tip but the new one is wide and round with the brass tipp but also a brass ring underneath? Can someone please help mr as I'm not sure which is which? Sorry not photos but will try and get some sorted
Which rotor arm?
- Thread starter chris001
- Start date
Willy Eckerslyke
Well-Known Member
The big one is the correct original type incorporating a governor device to prevent over-revving (?). But they're not 100% reliable so some of us replace them with the normal type instead. That's what I did and have not reason to regret it.
NickDunning
Active Member
chris001 said:
No. As previously stated, the big round ones are a device to prevent over-revving in TC's. Other than that they're the same.
Cheers
Nick
Retroreject
New Member
I have one of these fitted, tho its the Intermotor version
http://cgi.ebay.co.uk/Lucas-Rotor-Arm-R ... 4cf3453e90
have no problems whatsover (in that department!)
http://cgi.ebay.co.uk/Lucas-Rotor-Arm-R ... 4cf3453e90
have no problems whatsover (in that department!)
redrover
Well-Known Member
If you're looking to replace the rotor arm with a brand-spanking new one, I can highly recommend one of these:
http://www.simonbbc.com/rotor-arms/25d- ... -rotor-arm
They're made of some modern polymer material that isn't as brittle and prone to hairline cracks as the original black plastic units. They also fit far tighter than normal ones, as there is a bit of sprung steel on the underside to lock it tight to the top of the cam and stop it rattling as it goes round. That, and the brass arm bit is melted onto the top of the plastic rather than being held with a stud, which could split the arm over a number of years.
I had this problem on my 2000TC which caused literally weeks of head-scratching. Turned out the HT side was shorting to the dizzy base-plate every now and then thru the rotor arm which had a tiny hairline split in it.
They're cheap enough as they are, but you can get one of these red rotor arms in a bundle with an electronic ignition kit and new dizzy cap for under £30 from simonbbc. That's what I did and it brought a welcome end to all of my lengthy and recurring ignition problems!
http://www.simonbbc.com/rotor-arms/25d- ... -rotor-arm
They're made of some modern polymer material that isn't as brittle and prone to hairline cracks as the original black plastic units. They also fit far tighter than normal ones, as there is a bit of sprung steel on the underside to lock it tight to the top of the cam and stop it rattling as it goes round. That, and the brass arm bit is melted onto the top of the plastic rather than being held with a stud, which could split the arm over a number of years.
I had this problem on my 2000TC which caused literally weeks of head-scratching. Turned out the HT side was shorting to the dizzy base-plate every now and then thru the rotor arm which had a tiny hairline split in it.
They're cheap enough as they are, but you can get one of these red rotor arms in a bundle with an electronic ignition kit and new dizzy cap for under £30 from simonbbc. That's what I did and it brought a welcome end to all of my lengthy and recurring ignition problems!
I bought a new rotor arm the other fitted and all was well then all of a sudden, she starts miss fireing again!! I check the new rotor arm and it's burnt! Put the old one back in and all is well again..? I have no idea... I've replace the cap checked the points etc but still no answer.. It's a pain cause she's been good as gold and because I use her everyday it's becoming an issue... And the worst part... Being 23 all of my friends are now having a dig at me saying she's unreliable (to those words)
redrover
Well-Known Member
chris001 said:
Snap! I'm 23 with a 1972 2000TC! I've also had more than my fair share of ignition problems... and jibing from the neighbours.
Black burning deposits on a rotor arm and inside the dizzy cap as you describe is called carbon tracking. It's a sign of current arcing. Somewhere in the HT system the spark from the coil has to jump across a gap that is too big, causing burning. Normally it's when one or more of the 4 contacts inside the dizzy cap (to the spark plug leads) have moved, creating a larger gap for the spark to jump across, but as you've replaced the cap, it's unlikely to be that. It could be a simple case that the new rotor arm was slightly too small causing a bigger gap between it and the contacts.
But if you still have issues:
Have you checked your plug gaps? Big gaps would cause a similar symptom and possibly cause misfiring under load.
And are you using the correct type of plugs? Opinions vary as Rover changed their recommendations a few times during production, but Champion N6Y and N7Y (NGK BP7EFS and BP6EFS) plugs are generally considered the best for 2000TC engines. (If your engine naturally runs a bit rich, fit N7Y's and risk pinking, if it runs lean fit N6Y's and risk carbon fouling over short journeys on choke.)
Otherwise, check your coil resistances. http://www.international-auto.com/afla- ... n-coil.cfm It would be very unusual for a coil to put out more voltage than normal, as when they become worn the windings inside tend to weld together and result in less voltage output, but it's worth a check with the meter.
Check the condition of each of your HT leads and check that they make clean contact with the dizzy cap and spark plugs. Also check that the rubber suppressors on the end of the leads are intact. If there's even a hairline crack anywhere on the lead insulattion, they can short intermittently to the engine block rather than firing the spark plug. You can test this by running the engine in the dark and watching for blue sparks in the engine bay.
Whatever your problem is, it's definitely on the HT side. Unfortunately, it's probably going to be a case of trial and error until you've checked/replaced enough things to cure the problem! Welcome to my last six months... you've got the symptom, now find the cause!!
Let us know how it goes!
Michael