Hi everybody

Anyone know the difference (if any) in the NC23E engine comapred to the NC31 ?

I recently bought an NC31 (lovely bike, nicest bike I've had in nearly 40 years of riding) and I've found out that the engine was swapped by D&K to an NC23 E and I wondered if there was any difference that anyone is aware of ?

Apparently the guys at D&K swapped the engine and then the bike was sold not long ago on Ebay , could anyoone remember seeing it by any chance ? Anyway the guy who bouight it then sold it and I was the lucky buyer and to be honest I'm totally delighted with it in every way , what a lovely ride and superb build quality > Congaratulations Mr Honda (again)

Best wished to all other forum members

The s4 nc31 engine no. starts with nc23e so nothing to worry about

The connotation NC23E stands just for the engine family, not that the engine itself comes off another bike (e.g. the NC23). The engines are different though. I have the CB400 NC36 and the engine ID also starts with NC23E but it looks quite different from the NC31 engine.

Yeah, it's the same block on the inline 4's, just different cam profiles for the cb to give better midrange, also slightly diff carbs. But i think they may have changed the block from vtec onwards?

Ok I have a question

The NC23e engine appears on the CBR400RR NC-23 (89-90 I think) the CB-1 (also know as the CB400F) NC-27 (89-90) , the CB400SF NC-31 (92-98) and the CB400F NC-36 (98 - my personal fave).

They all look similar, except for some things that appear to be more or less cosmetic. The layout seems exactly the same, the size of each major group appears to be almost exactly the same and there don't appear to be any difference in angles. So the question

How similar are they? Could I use a CBR400RR or CB-1 manual to fix my 97 CB400SF?

Anyone know?

I can't find a damn thing written about my bike....would like to know more about it.

earthbound14 wrote:Ok I have a question

The NC23e engine appears on the CBR400RR NC-23 (89-90 I think) the CB-1 (also know as the CB400F) NC-27 (89-90) , the CB400SF NC-31 (92-98) and the CB400F NC-36 (98 - my personal fave).

They all look similar, except for some things that appear to be more or less cosmetic. The layout seems exactly the same, the size of each major group appears to be almost exactly the same and there don't appear to be any difference in angles. So the question

How similar are they? Could I use a CBR400RR or CB-1 manual to fix my 97 CB400SF?

Anyone know?

I can't find a damn thing written about my bike....would like to know more about it.

I wouldn't - you might get yerself into some trouble. The CB-1 motor isn't really much like the SF engine. For a start, the CB-1 has gear driven cams. As mentioned above, I think all the NC23E stands for is "400 Inline four/engine". Seems the lack of an english manual is a real bummer for SF owners. I should be able to get a Japanese version, if you all chip in, I dare say I might be able to get it translated.

There's a Russian manual that someone has translated into English. I'd be happy to send you a copy if you PM me your email addy.

alexibrow wrote:There's a Russian manual that someone has translated into English. I'd be happy to send you a copy if you PM me your email addy.

Can I get a copy as well?

Hi Sorry for being cheeky. Can you send me a copy please

Hi everyone,i've got this manual too(can send it if someone is interested).I can say it's quite good except wiring .Covers both-chain driven and gear driven cam engines with all carbs combinations .