Triumph T120 engine number

[Karlburgess]

Don’t know if anyone can help me with an engine number query on a T120 ?.

I have recently aquired a “ strike year “ Bonneville and am having a bit of confusion with it. It may be very pretty, but it’s odd !.

January 1974 registered ( M Reg )
Frame number starts T120, NG. so 1972
DVLA registered as 750 cc
Bike badged as 750cc
Right foot change 4 speed
Drum brakes

Engine number T120 LTT 750

The engine has a raised “ pad “ covered with Triumph stamps and T120 LTT 750 is clearly stamped over the top in large letters.

The engine also has the letter “ G “ stamped on each crank case where it bolts to the frame.

I am at a bit of a loss to identify the number, however, it’s a lovely bike, starts first kick and runs superb showing 12000 miles. It’s more of a puzzle than a problem. DVLA and HPI check out fine.

I would really appreciate any comments more knowledgable owners may have.

[Rex]

Replacement cases stamped in a random way? Engine and frame numbers should match but that engine number doesn't match any sequence I've seen.
It's a 1973 model-year too.

[Karlburgess]

Cheers for the reply.

No one I have asked about the number recognises it either.

Bike has only had a couple of owners, it came with a well used manual that someone scribbled the same number on, obviously quite some time ago.

The number itself may be peculiar, but does look original and is certainly not altered in any obvious way.

The person I bought it from knows a bit of its history and reckons it’s the original motor ?.

Also, T120 , 4 speed 750cc ?. As far as I know, 750s are T140 5 speed.

[mini-me]

I'd ignore the G it's  to pair up crankcase halves.

As for the rest the meridan strike/workers crap out/ it was a total balls up, they probably destroyed the records out of spite/or never kept any/or were pissed [on or off] at the time they stamped the numbers, or maybe one bloke stamped numbers,the other did the letters and the work experience kid wrote it down.

The whole BSA/Meridan saga is a parable of modern life.

[Rex]

Maybe it's a 750 as it had a Morgo or Routt conversion way back when, and someone thought it was worth put a number on a pair of NOS cases to reflect this?
As I recall, the Morgo kit had noticeably  different head finning to the Meriden version, and the Routt was different again and more angular.

[Karlburgess]

Thanks for the information.
The fins will give me something to look into.

[L.A.B.]

It's a 1973 model-year too.

'G' is 1972 model year. 'NG' is build date October(N) 1971 as 1972 model year T120 production started at HG 30870, July(H) 1971.

As for the rest the meridan strike/workers crap out/ it was a total balls up, they probably destroyed the records out of spite/or never kept any/or were pissed [on or off] at the time they stamped the numbers, or maybe one bloke stamped numbers,the other did the letters and the work experience kid wrote it down.

The Meriden workers would have no reason to destroy the production records of what became the Meriden Co-Operative!

The production record for frame NG ?xxx? almost certainly exists - if legitimate and should be held by the VMCC and TOMCC.
The engine number, however, is unlikely to be a 'factory' number.   

[Grunt]

Does the frame have the earlier higher seat loop or the lower type and what style seat catch has it got, the over centre clip or the plunger? Both will give a vague indication of frame year if your doubtful of the number, as will the coil mounting under the seat.