T-Series MGTC Carb Needles

[R6MGS]

We've been rebiulding the carbs on the MGTC and after weeks of waiting for parts finally had the chance the finish the rebuild. What we found is that the new needles(Moss) are bout 1/8 inch shorter than the originals...the old ones are marked "ES" (standard) and so are the new ones.My question now is does the shorter needle matter or is it irrelavent??

Thanks
Zack

 

[Roger]

What matters is the length from the shoulder to the tip. You should normnally install needles so that the shoulder is flush with the bottom of the piston. If the bit in the piston is shorter, it doesn't matter at all.
It may not matter about the business end either, if the taper is the same and the old needle stays well within the jet at full piston lift. Without seeing, can't tell!

 

[R6MGS]

Thanks for your reply....I also posted this on an MGT mailing list and they said the same thing, so far it seams OK....I guess we'll see how the car runs once it's together lol

Thanks
Zack

 

[Dave Russell]

Hi Zack,
I agree with Roger. Usually the last three or four stations (taper positions) on the needle are still in the jet by .300" or so, even with the piston in the wide open position. The stations are measured at .100" intervals. Even with the shorter needle there is still plenty of needle in the jet. This is backed up by the fact that the last four stations, 9 through 12, (.400" of length) are all the same diameter (.073") on the ES needle.

Here is a pretty good reference on SU needles. Your carbs have the .090" needles.
https://www.teglerizer.com/suneedledb/index.html
D

 

[RF Thom]

R6MGS

Use only genuine SU Replacement Parts. I used some parts from Moss, which were aftermarket source [probably China] and had all kinds of trouble, wouldn't idle, backfiring, trying to get the adjustment right. Finally in desperation I completely tore the carbs apart and examined each part in detail, against the originals I had taken off - and notices some differences, albeit very slight like radii size, heights etc. I bit the bullet and ordered genuine SU parts from Joe Curto [they were a little more expensive 718-762-7878] installed them and everything now works as per spec. The time delay agrevation out weighed the cost factor, and a road I don't want to go down again.

Regards, Bob

 

[R6MGS]

Yup, these are from moss but they look authentic(the boxes at least) they say "genuine SU" on the boxes with proper SU symbols...Also made in the UK, Moss must have changed their supplier after to many complaints. I did notice that a few of the parts were not exactly as originals but it was only minor differences(new throttle shafts were longer with no hole for stopper on the end...those weren't to fun to drill either)

 

[RF Thom]

R6MGS

Sorry I didn't notice you live in Mississauga, I writing you from Vineland, and gave you Joe's number in USA. However there is a guy right in East York - Blain Hughes [ Hughes Carbs - who handles only genuine SU parts].
He's at 32 Parkview Hill Cres. [St.Clair/Oconnor area]
M6B 1P8 416-750-1367 or cell 705-484-5307. He can help you out. If all else fails give me a call - 905-562-9117

Regards, Bob

 

[martyc]

[ QUOTE ]
Use only genuine SU Replacement Parts. I used some parts from Moss, which were aftermarket source [probably China] and had all kinds of trouble ---snip--- The time delay agrevation out weighed the cost factor, and a road I don't want to go down again.

[/ QUOTE ]

Just a point of information: I recently ordered a Carb Rebuild Kit from Moss for my SU's and they were "Genuine SU Parts" in the proper SU packaging, made in the UK and were pretty much perfect. Not sure when you had your bad experience, but my experience with Moss-supplied parts was good. Perhaps they changed their supplier?

Marty /ubbthreads/images/graemlins/driving.gif