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head and carb
Posted: Thu May 23, 2013 4:08 pm
by briandr
hi, struggling to identify engine in my new project carb has LZX1773 on cap and Pdc 1v on side on heated manifold .Head has Nos 120940 inside and 29 LO on front edge also small alloy stud at front.No plate on engine where plate was is stamped 1J 73, its been bored to+20 pistons marked AE 20397 /small numbers on edge +1.016 KSF/ crankcase marked 15H , 261, in circle toward the back of engine looks like 12A/ 497 under the breather pipe at front is an oval shape. Can anyone help me to identify.
Brian :

Re: head and carb
Posted: Thu May 23, 2013 6:32 pm
by IslipMinor
Can you post some pictures? Especially from each side, so that we can see the oil filter and the tappet chest under the exhaust manifold.
Re: head and carb
Posted: Thu May 23, 2013 8:10 pm
by bmcecosse
The 12 G 940 head is standard for a 1275 , but can be fitted to small bore engines too. However the piston numbers confirm it is NOT a 1275 engine......could be 998 or 1098 (frankly more likely) .
Re: head and carb
Posted: Sat May 25, 2013 6:31 pm
by briandr
hi sorry for delay have got photos of carb /engine /ect .it is reg as 1098/the head is red painted.[frame]

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Re: head and carb
Posted: Sat May 25, 2013 6:46 pm
by briandr
some more not good at this[frame]

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Re: head and carb
Posted: Sat May 25, 2013 7:30 pm
by bmcecosse
1098 - (or could be 998 using a 1098 block) - but sensibly done with a crankshaft damper fitted. Red head is worth an extra 5 bhp any day...... HIF carb - could be 38 or 44.
Re: head and carb
Posted: Mon May 27, 2013 3:50 pm
by briandr
Hi, many thanks looks like oil leaking past valves onto pistons ,would that mean guides and rubber seals to cure ? gratefull for your help.
regards Brian
Re: head and carb
Posted: Mon May 27, 2013 3:54 pm
by bmcecosse
No harm in trying guides - only put top hat seals on the inlet valves. You need a 1275 gasket with that head.....
Re: head and carb
Posted: Tue May 28, 2013 7:03 pm
by philthehill
The carb is fitted upside down on the inlet manifold!
Re: head and carb
Posted: Fri May 31, 2013 9:51 pm
by briandr
Hi folks thanks for info have made notes great help.

Re: head and carb
Posted: Mon Jun 17, 2013 10:54 am
by briandr
can I ask why top hat seals on inlet valves only ? there are seals on both valves on this 1275 head .

Re: head and carb
Posted: Mon Jun 17, 2013 11:37 am
by bmcecosse
Because the exhaust valves NEED lubrication.
Re: head and carb
Posted: Sun Jun 23, 2013 9:38 am
by briandr
thanks will do as I am told

Re: head and carb
Posted: Sun Jul 14, 2013 10:29 am
by briandr
Hi been trying to get head gasket set for 12g940 head to 1098 unit Bull Motif say 1275 or 1098 wont seal is there someone I can get right parts from thanks.

Re: head and carb
Posted: Sun Jul 14, 2013 3:22 pm
by bmcecosse
You MUST use 1275 head gasket....... Just buy at local autoparts place...........ask for gasket for 1275 Mini. Are you sure you know what you are doing?? The likes of normal Minor suppliers will have no idea about fitting a 940 head to a 1098. I see the block has been 'pocketed' to give clearance for the exhaust valves. Have you ground in the valves and fitted the new inlet guide stem seals?
Re: head and carb
Posted: Mon Jul 15, 2013 8:38 am
by briandr
thanks will take old gasket to local shop ,and no not sure what I am doing,but brilliant with side of beef!

,its a hobby.