Help needed to identify engine please!

[blueflag]

Hi,
I bought a spare motor for my triarm, it was only on closer inspection (I'm new to these bikes!) that I realised that it has a few differences to the one in my triarm, noteably, no oil cooler, the engine cover on the r/hand side is different with a plastic chrome effect cover. Head is slightly different too.
I could do with finding out what it's off so I can sell it on assuming I can't use it in mine.
The engine number is NC23E-1203930.
Cheers,
Mike

[scratchin]

are you sure you've got the numbers right

[blueflag]

Yes, it's pretty clear. I would have thought that an NC23 was an NC23. Reckon I've got a lot to learn!
With the shiny cover I have a feeling it may be off a naked bike....
Cheers
Mike

[Spanners]

Well you seem to have fallen foul of the "if its got NC23 on it then its NC23".
NC23 was used for the prefix for the engine number on an engine in the Honda Inline four fourstroke engine family. The frame numbers are what determine model of machine, the NC23 prefix for engine was used between 86 & 89, then the engine`s carried on the NC23 prefix but machine frame prefixes changed depending on model. So NC29/NC31/NC27 ect all have engine numbers starting with NC23. If you get what I mean.
What you have is an engine from the CB400FK/ CB400FK II.The model with the steel tubular perimiter frame single front disc ( dispatchers love em).
Still geardriven cams but with differant gearbox ratio`s ect the cylinder head is larger in dimentions but has same valves & pos cams are same to but of course your top engine mount is in the wrong place, you could put the cylinder head from your model NC23 on it & still use as I dont think without checking that the ratio`s in the gearbox are that differant. Other than that and the general outward appearance of the cases there`s much differnce, it should bolt in if you change the cylinder head over.
Hope that helps.

[blueflag]

Thanks Spanners!
That's great, looks like I can at leastget it on Ebay now I can put a name to it. Pity I wasted all that time lapping in the valves!

[Spanners]

Hi
If it wer me ,I would hang on to it. The basic engine is the same, shares the same crankshaft,clutch assy and only a few of the gears in the gearbox look differnt, all the other parts share the same part numbers with the Tri Arm(same). because the clutch & crank are the same your primary reduction ratio is the same so the main things to swap to get it same as Tri arm engine would be Cylinder head & oil cooler, & these you will prob fing on the E of bay.
Hope that helps.

[Mikiboy]

Sounds more hassle than its worth by the time you change all the gaskets.
I'd just sell it and get a unit ready to drop in.

[piston]

Well having read spanners post, I thought that to just swap a cylinder head over & fit an oil cooler would be fairly straight forward, as bluflag says he`s already laped in the valves on the CB400F engine, im sure he`s more than capable to do the job ,only be needing a head gasket. Got to be easyer than arranging carridge or trying to sell an engine on ebay.
But as you say from your point of view im guessing, those who arn`t able to do mechanicle jobs like that may find it easyer to just swap the whole thing.
But hey I spose he was only offering advice.

[blueflag]

The head is oh so very slightly different , around the oilways and water galleries, reckon it would be possible to swap over the complete head and barrel assy though I havn't checked properly.
Thanks for all the input by the way, it's nice not to be alone!
Mike

[Spanners]

Hi,
With regard swapping barrells Id leave them to, The CB400FK uses tri arm pistons as std any way, the engine is same bore & stroke & the CB motor uses the same head gasket as Tri arm so wouldnt be any point changing it.