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Old 04-22-2012, 05:28 AM   #5101
clanbree
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Quote:
Originally Posted by Kingkobaa View Post
Thanks! For a second I thought there was something wrong with it.
You're most welcome.
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Old 04-22-2012, 11:43 AM   #5102
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Quote:
Originally Posted by scrambler66 View Post
I guess the 29hp AX1 is a myth. The AX1 stainless steel manifold has no larger diameter and the AX1 carburetor is also the same (the jets etc. as well) as the one from the NX. And the cams? I finally got a couple of AX1 cams a couple of weeks ago. But after measuring, it turned out that the lifting is exact the same as the NX250. Now what? Some guy in this forum reported 0,75mm more lifting for the AX1 cams – that’s correct, but only compared with the Xl250 degree cams of that guy! Luckily, I got a XL250 degree factory manual and wouldn’t you know it: the degree cams got less lifting than the NX250 …

But there is still a little hope: it might be that the first AX1 model got those 29hp and later models only 26hp since in the NX250 parts list two different cams occur. I found a few AX1 part numbers, and they suggest the following scheme. For instance, the brake pedal of the AX1 (which was produced earlier that the NX250) has the part number 46500-KW3-000. And the NX250 brake pedal the part number 46500-KW3-670. So it looks like that the differences between the two models are marked by the last three digits.

I've been thinking of this too... I just about bet the US NX250's got the short lift cams and almost bet all the NX~AX250's abroad got the high lift.

(Or, they just made a mistake and called the US NX's 26hp)

I can't recall where I saw it, but Honda was improving emissions even before the NX250... So... I wouldnt put it past Honda N.A one bit to give us the "greener" or "Magical, mystical tree saving" cams and the rest of the world not yet following us, the cams it was designed to have.

Also, oddly. I ran across a post on YOUTUBE that said the NX250's top speed ON PAPER was set to 90 for TAX reasons, but it would actually go faster. Much like the Nighthawk/CB700SC was "700cc's" and not a 750 for tax purposes...

Quote:
Honda marketed the CB700SC (also called Nighthawk 700S) in the US from 1984 to 1986, configuring the bike's specification to avoid a 1983 US tariff on motorcycles over 700 cubic centimeters
Lots of mysteries around some bikes.... And just who is this "John Galt?"
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Old 04-22-2012, 12:13 PM   #5103
valvecrusher OP
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There are also multiple versions of the AX1 and XL250 Degree, even the overseas(non US) versions of the NX250.

Honda is well known for several versions of each bike model....
such as,
the 239cc NX250, and/or NX250 'reduced effect'
and the XL250 Degree 'reduced effect',
as well as AX1 'reduced effect'.
to go along with the regular XL250 Degree, NX250, and AX1(NX and AX were same 29hp, XL degree(hi-po) was 24hp? Sir Mobbs?)

"Reduced effect" has been around Honda's since the mid 80s, as well....
It is their term for less emissions, less HP, and less powerful engine dynamics, but has generally been consistant with the following modifications..
(some of, not limited to, including~ maybe all, but in different combinations, depending on model)

1.smaller ports in the cylinder head
2.smaller carburetor, and/or small(lean) jetting
3.lower lift in the cams
4.lower compression piston
5.heavier flywheel
6.lower geared transmission ratios



It's been posted here in the thread, but not concluded.....officially..

Euro bikes HP is measured(was measured in late 80s) at the CRANK...(true engine hp rating)
Euro = 29hp

U.S. models were measured at the rear wheel,
thus including driveline parasitic loss, and drag at a 10% rate..(chain, transmisison, clutch, oil, bearings, ...etc)
10% of 29hp is 2.9hp...

29hp crank - 2.9(loss 10%) = 26.1 rear wheel hp for U.S. models rating..


At least that is how i understood the difference in the rating...

Euro's measure the engine's total actual output, and the U.S. measures final driven wheel hp, after transmission through the driveline..

ymmv



The megacycle cams are the only proven NX/AX/XL-degree high lift cams, to date, that's why they(AX-1 cams) are not listed in the FAQs, or Index.


It would be awesome to have better cams, so if anyone finds more conclusive information, please re-visit this issue, and/or PM me the information, and i will update the FAQs/Index
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Old 04-22-2012, 05:39 PM   #5104
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Quote:
Originally Posted by Goofy Footer View Post
Their sales person was clueless about the NX. They say they don't have the bike in the computer system (and they might not).
they do (or at least did), but alas, it (the NX) lives in that zone between "dirt bikes" and "street bikes". Depending where you look, it's in either. Not both.

One or the other, but you have to look for both... Since tools can't figure out what it is before they list it as so.

Quote:
Originally Posted by Goofy Footer View Post
Before I forget, I recall that the BBR CRF230 Fork Springs are nearly the exact same diameter as the NX (both 37mm forks conventional forks, the springs were a few mm different from what people on forums had measured).
The BBR CRF230 springs were also roughly 1.5 inches longer than the stock NX ones. I believe the BBR springs were .53 flat spring rate. I'll update with more specific info once I look up my notes.
Wonder what the 230SM's are?

Been a long time, but I once compared the two (230SM-NX) in suspension travel, and IIRC they were either close, or dead on.
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Old 04-22-2012, 08:53 PM   #5105
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More CRF230 Spring Info

Quote:
Originally Posted by IheartmyNx View Post
they do (or at least did), but alas, it (the NX) lives in that zone between "dirt bikes" and "street bikes". Depending where you look, it's in either. Not both.

One or the other, but you have to look for both... Since tools can't figure out what it is before they list it as so.



Wonder what the 230SM's are?

Been a long time, but I once compared the two (230SM-NX) in suspension travel, and IIRC they were either close, or dead on.

I stand corrected. They have the NX in the the computer system as a street bike but there isn't much info http://racetech.com/ProductSearch/2/Honda/NX250/1988-90.

According to http://www.racetech.com/HTML_Files/C...erMPG2011.html the Perethian NX250 has RaceTech emulators in it. Maybe there is hope for the NX fork dampening.

I seriously doubt the CRF230M has aftermarket springs specific to the M. I would assume most guys with the M just install the standard BBR CRF230 springs which they could cut down to their size (if needed). Thumpertalk might have that info. Even some stock CRF230F springs might be better than the NX.

If somebody has a friend with the CRF230, swapping the springs for a test fit on the NX should be easy. With so many CRF230 owners upgrading to heavier fork springs, I'm sure somebody on the forum would be willing to get rid of them cheap. I don't have the NX forks on my bike any longer or else I would try.

These are the numbers I found while researching:
CRF230F stock fork spring .21/.51 progressive ----------> 1.175 OD x 23 5/16 long
CRF230F bbr fork spring .53 flat rate ----------------------> 1.175 OD x 23 9/16 long
NX250 stock fork spring unknown rate progressive -----> 1.094 OD x 22 3/16 long

I just measured the springs with the tape measure I had on hand. Still, the springs should fit.

Goofy Footer screwed with this post 04-22-2012 at 09:06 PM Reason: Added info
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Old 04-22-2012, 11:08 PM   #5106
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who will try it?

Quote:
Originally Posted by valvecrusher View Post
Euro bikes HP is measured(was measured in late 80s) at the CRANK...(true engine hp rating)
Euro = 29hp
U.S. models were measured at the rear wheel,
thus including driveline parasitic loss, and drag at a 10% rate..(chain, transmisison, clutch, oil, bearings, ...etc) …29hp crank - 2.9(loss 10%) = 26.1 rear wheel hp for U.S. models rating..
That explanation makes a lot of sense. But the main problem with that hypothesis is, why would Honda do such a thing exclusively with the NX250? The 650 Dominator, for instance, was introduced at the same time (end of 1987) and I never heard of a US 40 hp version.
But you got a point with the emission laws. It may be that Honda was not able to meet the standards with the 29 hp high lift cams. If you take a look at the AX1 parts list you will notice that the first two years (1988-1989, J + K models) got different cams.
And those cams are still available and they are not even expensive. The only thing we need now is someone mad enough to buy them, or the 29 hp NX250 will remain a myth



By the way: here's a link to the official Honda announcement of the AX1 http://www.honda.co.jp/news/1987/2871120a.html



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Old 04-23-2012, 05:22 AM   #5107
IheartmyNx
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Quote:
Originally Posted by scrambler66 View Post
That explanation makes a lot of sense. But the main problem with that hypothesis is, why would do Honda such a thing exclusively with the NX250? The 650 Dominator, for instance, was introduced at the same time (end of 1987) and I never heard of a US 40 hp version.
But you got a point with the emission laws. It may be that Honda was not able to meet the standards with the 29 hp high lift cams.

That would be my hypothesis.. But I know how "laws" work in this country too.

Maybe to whom it mattered, shaft or rear wheel was irrelevant.

Thus the 10% loss to make it "legal"... Or gain. Depending on how you look at it.

(Re the import tariff on 700+ cc bikes And just for fun, Google "Chicken Tax")


There is another way to explain this myth, but that would involve a fresh motor and some Dyno time.
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Old 04-23-2012, 07:08 AM   #5108
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Fork Springs

I am down in San Diego for the week and I will be rebuilding my forks as soon as I get back to Fresburg, so you guys have definitely got my attention. Well, that and the Ayn Rand reference. I could stop by Race Tech on my way home, or Progressive for that matter. Can somebody break out a caliper and get the OD of the fork springs? My other question would be if any one has experimented with a plastic tank, with shrouds, to see if any fit? I would like to find something with a little higher capacity than stock. 4 Gallons possibly? That may change the fork spring a little. If you have not used the Race Tech Gold valve emulators, the set from Race Tech I have in my SV make a big difference in the front end, but that is a bike that regularly sees 100 mph. I suspect the springs and heavier oil in the little bike will be plenty, especially considering the SV's stock shock is going on the Nixie. I tried the GSXR 600 shock in the back, but with the junk forks I did not see enough of a difference to justify the need to run the bike with just a Uni filter. The ZX 10 shocks fit as well, FYI
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Old 04-23-2012, 07:28 AM   #5109
MechaNikos
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Parts wanted: 1993 nx250p

Hi all,

I've had my NX since 1997 and have been enjoying it since.

Unfortunately, the bike was knocked over and the headlight and front fairing have been broken.

Buying new parts costs an arm and a leg, so I'm looking for used ones. These are:

Headlight
Front fairing (black/silver with "Dominator" mark)
Instrument cluster bracket

Any help will be much appreciated.

Many thanks,

Nicholas.
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Old 04-23-2012, 08:34 AM   #5110
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Quote:
Originally Posted by scrambler66 View Post
That explanation makes a lot of sense. But the main problem with that hypothesis is, why would do Honda such a thing exclusively with the NX250? The 650 Dominator, for instance, was introduced at the same time (end of 1987) and I never heard of a US 40 hp version.
But you got a point with the emission laws. It may be that Honda was not able to meet the standards with the 29 hp high lift cams. If you take a look at the AX1 parts list you will notice that the first two years (1988-1989, J + K models) got different cams.


It may go some way towards explain why my 88 AX destroys my friends 92 model despite them both being in excellent condition with the same gearing.

I love how shocked people get when the find out my bike is 24 years old
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Old 04-23-2012, 03:05 PM   #5111
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Quote:
Originally Posted by scrambler66 View Post
That explanation makes a lot of sense. But the main problem with that hypothesis is, why would Honda do such a thing exclusively with the NX250? The 650 Dominator, for instance, was introduced at the same time (end of 1987) and I never heard of a US 40 hp version.
But you got a point with the emission laws. It may be that Honda was not able to meet the standards with the 29 hp high lift cams. If you take a look at the AX1 parts list you will notice that the first two years (1988-1989, J + K models) got different cams.
And those cams are still available and they are not even expensive. The only thing we need now is someone mad enough to buy them, or the 29 hp NX250 will remain a myth



By the way: here's a link to the official Honda announcement of the AX1 http://www.honda.co.jp/news/1987/2871120a.html



ok let me ask you something now

the part numbers in the above picture

are the more agressive cams?

Because some site refer to them as NX250 OEM parts and not for the AX-1

are we sure that those are the aggressive cams?
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Old 04-23-2012, 03:55 PM   #5112
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Quote:
Originally Posted by MechaNikos View Post
Hi all,

Buying new parts costs an arm and a leg, so I'm looking for used ones. These are:

Headlight
Front fairing (black/silver with "Dominator" mark)
Instrument cluster bracket

Nicholas.
Check out ebay.de I saw a headlight/fairing/instrument cluster there and it will be closer to you than the US. I was trolling there trying to find a cylinder head. No luck for me!
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Old 04-23-2012, 07:01 PM   #5113
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Haha the idiot I am I ordered neoprene fork wraps and didn't realize they were for a mountain bike!
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Old 04-23-2012, 09:07 PM   #5114
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AX-1 factory manual needed

Quote:
Originally Posted by SaDoW View Post
ok let me ask you something now the part numbers in the above picture are the more agressive cams? Because some site refer to them as NX250 OEM parts and not for the AX-1 are we sure that those are the aggressive cams?

AX-1 and NX250 are basically the same models with only a few differences concerning wheels and fairing, but the engines are identical. The official Honda name of the AX-1 (which is only a sales tag) is NX 250 and the engines are MD21-xxxxx . Consequently, AX-1 and NX250 share the same part numbers: xxxxx – KW3 – xxx.

That’s why the part numbers of the Ax-1 and NX250 camshafts are identical.

So all AX-1 and NX250 share the same camshafts, except for the very first MD21 engines used in the first AX-1, they had different cams. The reason is not known, I suggest that they might be more aggressive and account for the 29ps, but that’s not proven at all and a mere hypothesis. We won’t know until someone buys those cams and measure the lift.

Or we would need someone with an AX-1 factory manual and look up the lift of the cams.

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Old 04-23-2012, 09:48 PM   #5115
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I'm a proud owner of an NX! I've had it for about a year and just now getting around to post here.

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