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Discussion Starter · #2 ·
Re: CB400T 27ps vs CB400T 43ps

Well,
I know that the camshaft is of diferent size (37mm on the 43hp and less for the 27hp) and probably the carburetor (mine is a 31c).
Does anyone knows if the compression test gives diferent values for the diferent versions? My results were 160 for both cylinders...
Opinions???
 

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Re: CB400T 27ps vs CB400T 43ps

I think part of the lack of response was a translation difference... No idea a "ps" was "HP"..... Are you discussing camshaft lift? diameter of the lobe base circle or what?
I did not even know a lower HP version was available, much less what differences it would entail....
 

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Discussion Starter · #4 ·
Re: CB400T 27ps vs CB400T 43ps

Sorry... PS is metric for Hp, 1ps=0.986Hp
As for the camshaft (hope this sounds logical) the diferences betwen them is that the 43hp versions enables the valves to open more!
I don´t know if the carbs are the same, the manuals I have don´t refer the type of carburetors I have.
So if anyone have more informations please share!
 

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what markings can you see on the side of the carb body casting? there should be two letters followed by 3 numbers, right?
I wonder if the carbs used on the 27 HP version were the same as on the CM185?

Anyone know the output of a 185?
 

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Discussion Starter · #6 ·
No, there are:
Two letters on top: VB
Two numbers and three letters on bottom: 31C BPL
In the shop manual the carburetor seting number for the 1978 CB400tII is VB21A, I have a VB31C.
Any info on this tipe of carburetor?
 

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How can you tell what one you have? I may go look at a 78 cb400t on CL soon. Here it a
is the listing if a pic will help. http://dubuque.craigslist.org/mcy/2150608846.html
I have not found anything listing such low HP as 27 for this bike. The T1 (cheap version I suppose) is listed at 40-43 HP depending on where you look. If one has more guts I would guess its the T2 (more $ version with electric start,Com-Star wheels,tach)

Where is 27hp claimed for it? Perhaps this version was not sold in the USA.
 

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I've seen the 27hp CM400 listed on bikez.com before. Its classed as a 'reduced effect' version, with the normal version having the same 43hp as the CB. Here's a comparison of the 1980 model.

Reduced effect: http://www.bikez.com/motorcycles/honda_ ... t_1980.php

Regular: http://www.bikez.com/motorcycles/honda_ ... t_1980.php

I never really heard about a reduced effect version until I bought my Gladius. In some markets they detune some bikes (in the case of the Gladius just controlled by a different fuel mapping in the ECU) for learners until they have a certain level of experience under their belt.

Not sure how to tell the two version by looking at them though. Just checked my manual and I don't see anything about the VB31C carb either.
 

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I know that smaller bikes suitable for new riders have been restricted in power output, but a 400 would not fit that profile in the UK. Learners up to 125cc and 16-17years 50cc on the road, regardless.
 

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Discussion Starter · #10 ·
Hi there!
Thanks for the replies! :)
The only diference between the two versions is the camshaft.
The 27hp is 34,5 mm and the 43hp is 37 mm. Everything else is the same. There were restricted versions of the CB 250T/N and the CB 400T/N only for the German market!
As for the carbs, in Europe main land they have diferent designations from does in US and UK markets, so I still dont know if I have 32mm, 30mm or 28mm carbs. Any more info???
 

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hopefully the reduced effect bikes are only for Europe and Japan!
 

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The Hawk T I was actually the straight line high performer of the pair. It was lighter weight because it had no starter or tach. Only drawback was the drum brake up front and having to kickstart it only
 

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I know this thread is probably dead. but is there anyone who has actually confirmed this problem?

i'm intrested in buying a used CB400N actually, but is also came in a reduced effect. the one i'm looking at is probably one of these reduced bikes. the current owner took it to a garage and they estimated the power at around 20kW. which would be close to 27hp.

now what i want to know is: is it possible to exchange camshafts? or would that cause problems with the camshaft rockers or a misfit in any other way?
may be a stupid question, but i don't have a lot of technical experience in this area.

any help would be welcome.
 

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No members in the last 5 years have posted anything about doing a change over. It's had some random discussion is all. I looked into the differences quite sometime ago and IIRC the only difference was the camshaft.
I'll refer you to Honda Motorcycle Parts, Kawasaki, Suzuki and Yamaha Motorcycle Parts - ATV, Classic Bike, Dirt Bike Parts to look up the part numbers involved with each version. They never made it to the US so there's no easy interchange I can use.
Parts to be compared are camshaft, rocker arms, intake and exhaust valves, pistons, cylinder head and carbs.
Looking forward to what you find
 

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If you got 27 hp at the rear wheel , that is less than the 36 hp of the 'regular' engine/camshaft. The 27/43 hp rating was taken from the countershaft or the crankshaft; I'm not sure which. So, it is possible that your engine is possibly, less than optimum condition?
 

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Sometimes its best to go directly to the source when looking for accurate information, I couldn't find much directly from Honda, but here's the thread from a German Honda forum, its all here.
Cheers!

Just use google chrome and select translate German to English, unless you read German that is.

Twin Motoren drosseln und entdrosseln
 
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