NX250 Thread -- official ADV owners manual

[tntmo]

Cam chain was stretched a bit, not all the way loose though. Teeth all stripped on the cam drive gear on the crankshaft, chain slipped and piston hit the exhaust valves. Cam gear is integral with the crankshaft, so I need to buy an entire crank. Piss poor design.

[Gebogen]

Okay what is the process for using the vynal? Heat gun? Any prep involved? That came out very nice.

[IheartmyNx]

Originally Posted by tntmo

Cam chain was stretched a bit, not all the way loose though. Teeth all stripped on the cam drive gear on the crankshaft, chain slipped and piston hit the exhaust valves. Cam gear is integral with the crankshaft, so I need to buy an entire crank. Piss poor design.

If you fill in your location, someone might be able or inclined to want to help you more... If you're in or around middle TN, PM me.


Otherwise, PM (Preventative Maintenance) or how the bike was treated, is a bitch....

I got mine at 13k, have not rode it ONE day where it hasn't been in the red and it has over 26,000 on it.

I havent so much as adjusted the chain tensioner.

I beat it like a red-headed rented mule daily and have not had so much as a hiccup.

When the horn starts sounding weak or dead, that's my que vibes have loosened the positive battery terminal and I need to tighten it.

If I ever get the Valvoline oil out of it, it will NEVER EVER EVER go back in it again (twice now; the clutch sticks and it takes FOREVER to warm up on cold days, shifting is VERY poor unless it's at operating temps, and the lever had to be adjusted after the change so it would stop rolling in gear.).

Otherwise, rear tires are the worst part of my bike... If I can stop backing-it-in EVERYWHERE, EVERYDAY I ride it, I might can get over 3,000 miles out of one.

Hopefully the spoons I just bought will end all my screwdriver innertube punctures

[clanbree]

Originally Posted by tntmo

So much for reliable, less than 15,000 miles isn't that impressive.

I'm starting to think I'd better replace that timing chain tensioner on my 4,100 mile 1988 NX.

[tntmo]

Originally Posted by clanbree

I'm starting to think I'd better replace that timing chain tensioner on my 4,100 mile 1988 NX.

The tensioner seems like it worked fine, and it wasn't extended all the way. If I had checked it the day prior to the engine crapping itself, I wouldn't have been overly alarmed at it. Maybe it did fail, but even then I don't know how all the teeth on the crankshaft got stripped out.

[SAKONE]

Originally Posted by Gebogen

Okay what is the process for using the vynal? Heat gun? Any prep involved? That came out very nice.

This was my first try at this vinyl wrap. Clean the surface as if you were going to paint it. Just basically have a section of vinyl ready cut for a section of plastic but have 2/3/4 inches overlap of vinyl. Then just peel and stick, using a heat gun to basically get the curves correct along with a plastic scraper to smooth out the vinyl. I did mine around 11pm-1am since I had other projects to finish and it shows in my work. At 30mph it looks great, and 0mph you can tell its vinyl because of the edges. It takes some patience. Just careful with the heat gun. You can actually remove and re apply it if you get bubbles/creases.

I didn't sand the old sticker glue off all the way down and it shows up on the vinyl. I just did this because I had no time to shoot paint and would hate it if I were to scratch paint. Vinyl is forgiving and it shows when you apply the material. Cost about $120 for the bike. If you want something besides flat black and doesn't need to be maintained this would be it for appearance upgrades.

[thirstybuck]

Originally Posted by tntmo

Cam chain was stretched a bit, not all the way loose though. Teeth all stripped on the cam drive gear on the crankshaft, chain slipped and piston hit the exhaust valves. Cam gear is integral with the crankshaft, so I need to buy an entire crank. Piss poor design.

Sorry to see this. I'm in the same boat, but my crank cog is ok so I found a used top end.

On that note, is there a way to determine if the tensioner is functioning properly? I want to be sure when I put everything back together.
Thanks.

[tntmo]

Originally Posted by thirstybuck

Sorry to see this. I'm in the same boat, but my crank cog is ok so I found a used top end.

On that note, is there a way to determine if the tensioner is functioning properly? I want to be sure when I put everything back together.
Thanks.

I think the tensioner must have failed on mine.

Does anyone know if this crankshaft can be pressed apart? I may have found a deal on a used crankshaft but the connecting rod bearing is questionable.

[scrambler66]

For some time I was thinking of boosting the power of my Nixie – AX1 cams did not lead to more ponies. In Brazil Honda is selling the XRE300, which engine is basically taken from the NX without the water cooling.





XRE300 tuning parts such as piston, cams or even a forged connecting rod are available https://www.hjmotos.com.br/forged/534-forged-connecting-rod-honda-xre300.html , for even reasonable prices. So now we have to find out more about the XRE300, for instance technical data or parts lists, to make sure that the parts will fit

Apprently a french guy already used a XRE310 piston in this NX, he calles it NXR310. Since the stroke of the NX is longer, we will even get 310 cc out of it

[IheartmyNx]

What would help out tremendously in the power department is if we could get the specs off the liquid cooled NX400.

The NX is already a stroker compared to MOST 250's... I don't need anymore STROKE. Bore, is another story.

[IheartmyNx]

Originally Posted by scrambler66

Apprently a french guy already used a XRE310 piston in this NX, he calles it NXR310. Since the stroke of the NX is longer, we will even get 310 cc out of it

Yes, but any word on the compression ratio?

If it's lower, depending on how you look at it, it might be counterproductive...

Originally Posted by radpat

Yes Honda Japan did it on this bike. Size is 92x60 mm, I don't know wich piston and cracnkshaft they used.
But, if you bore the cylinder to 78mm you can insert a 300XR piston, you get a 310 Cm3 NX and you keep your standard cranckshaft.
Standard Bore x stroke: 70.0 x 64.8 mm.
Bye

Originally Posted by kiriakos

Any way , this is another ( Only for Japan toy ) , and any search for this parts , will end up in vain .

Some time on Google searching all Honda Single-Cylinder engines with 60mm stroke and 92mm bores might turn fruitful...

Might not...


Check THIS out for inspiration.

Using a KTM piston!!!

http://www.supermotojunkie.com/showt...upermoto-build


While this guy (follow the links) had major problems finding parts. http://www.johnnystoybox.com/piston_comparison.htm

[IheartmyNx]

Ok ok... Hiccup!


Bike won't start.

Runs, but won't start.

Why: Left... Or should I say, "found", the bike with the key in it and on. Battery, dead.

Ran it off, fired right up. (4th gear fellas)

Decided to ride thinking it'll charge the battery... No.

Couple of down-hills I killed it and tried the starter... Nothing.

Battery Terminals: Tight.

Runs with the light half dead and yellow, horn worked the first time but later sounded like a dying animal...



Is a diode open, shut or $%it, I don't know... I hate electricity-fyed things....

What could it be???

I'll put it on a charger sometime running it off gets to be too much of a pain My guess is that'll fix it though.


Wonder what a battery and starter weighs...

[clanbree]

Originally Posted by IheartmyNx

Is a diode open, shut or $%it, I don't know... I hate electricity-fyed things....

What could it be???

It sounds like it may be as simple as a sulfated battery. A sulfated battery will niether accept nor hold a charge without some coaxing. Our charging system needs a good battery to work properly, so it may seem that alternator isn't working. Trust me, it is. If it had not been, the bike would not have continued to run until you shut it off.

If a battery is left standing in a discharged condition the lead sulfate on the plates inside will become hard and have a high electrical resistance. The lead sulfate may become so hard that normal recharging will not break it down. Most charging sources, engine alternators and battery chargers, are voltage regulated. Their charging current is controlled by the battery's state of charge. During charging, battery voltage rises until it meets the charger's regulated voltage, lowering the current output along the way.

When hard sulfate is present, the battery shows a false voltage, higher than it's true voltage, fooling the voltage regulator into thinking that the battery is fully charged. This causes the charger to prematurely lower it's current output, leaving the battery discharged. Charging at a higher than normal voltage and low current may be necessary to break down the hardened sulfate.

The way to salvage a sulfated battery is to charge it at a high voltage rate (2.5 ~ 3.5 volts above it's rating) until the sulfates start to break down. The battery will start to off-gas and the electrolyte will bubble. Once it starts doing that, turn the charger down to a lower setting and let it trickle charge over night.

[IheartmyNx]

Clanbree.... Thanks a ton. Will try ASAP...



Big Bore...

I've wondered, for some time now, at the similaritys of the jugs off this bike...

I swear they look familiar

Via Google... NT650 Bore x Stroke: 79mm (Hmmm) x 66mm.

EDIT: Quick eBay search says no way, Jose...

[gforcephuket]

Thanks for your nice comments fikse and plz do excuse my late reply, been pretty wrapped up with work and other things so not spending much time online recreationally.

Regarding a couple of your questions below I must first say that I'm hopelessly inept mechanically, insofar as skills and knowledge. While I've been riding for over 30 years it's just a fact of my life I can't change. I know when a bike is working properly or not and can certainly point mechanics in the right direction but that's about where it ends. So I get everything done at local shops here in Thailand. The upside is that it's really really cheap to get stuff done here; the downside is that most local mechanics speak very little or no English and my Thai is lame, so more than half the time I don't know exactly what they do to my bikes or how they do it -- I just can know if something is right or wrong after a few minutes of riding the bike. I know that sounds a bit iffy but it's been working for 12 years I've been here, knock on wood.

So I'm sorry that I can't tell you exactly how they got in the DZR shock but it's in there and works fine, much stronger than the stock, though yes it's A LOT higher (but I have a 36-inch inseam, so no problem) and not sure how much compared to the SV650's (though yes, I'm sure it's softer given the DZR's off-road inclination.

Because the seat height was much higher and was forcing me forward toward the tank too much, I had to have the seat re-done (which I had already made quite higher than stock). So for just $10 I had the seat completely re-scultped recently (into a nice 2 level jobby) and it's just about perfect, but I have to take take it back and have him add a bit more height as he took off too much (making it about normal AX-1 height, which is too short for my long legs). I'll take a pic after I get the seat re-done again soon.

Regarding brake lines, I forgot to mention in my mod list that my master brake cylinder is also not stock, (frankly I'm not sure what bike it's from, a case as per above of little communication with my mechanics, but it works . But yes you are correct, it's a straight line from the reservoir down to the brake.

The master brake cylinder I have on there now is pretty good, especially with the braided lines and good pads, but I'd like to put on something even stronger -- can anyone recommend something that would work. I asked the guys at one shop if an XR 250 mbc would go on there but they weren't sure and said they'd actually have to get one and try it. Any advice about this would be appreciated.

I'm quite sure the Supertrapp isn't specifically designed for the NX/AX-1, in fact I'm personally not aware of any aftermarket exhaust specifically for these models, though there could be. I'm not sure what bike this Supertrapp was originally designed for, perhaps an XR?? It works good and sounds great but I can't really say for sure I'd recommend it. Frankly since I've had that on, the bikes peformance (I ride it hard like all my bikes) has not been as consistent compared to the stock, though I'm not sure if that's related to the Supertrapp or to not just having the carb properly tuned (which mechanics aren't super great at here compared to back home).

Thx for the advice about the KTM made in India! I've been thinking a bit about getting a new 690, but I'm pretty sure the KTM we'd get in Thailand here would be made in India....And you're right, overall you just can't be Honda quality, I love my little gixxer and Ninja 650 too but at heart I'm a Honda guy.

Good luck with the NX re-build -- it'll be worth it! Again I'm not Mr. Mechanical but anything general or not too complex I'll be glad to help if I can.

Originally Posted by fikse

Thats a nice piece of Honda Quite special colour Youve choosed. Nice! Lots of nice photos.
The rear suspension Youve used, Ill guess its a bit softer than the one from SV650, as several here uses. Is it possible to drill new mounting holes at the lower "fork" on this unit, as you can do with the SV-version? Personally Im not high, so would love to stick with almost same height as original
Im looking for braided lines as well, possible getting a friend of mine to make it for me. Does I see correct if you have connected the braided line directly to the top brake reservoir via a banjobolt, getting rid of all of these "extensions" in variable dimensions? Do you have braided line all the way from reservoir down to the calipper?

The Supertrap, is it designed for the AX/NX? Looks nice. Ill guess the sound is jolly good, waking up sleepy car-drivers

I absolutely agree with you the NSR is something for itself Never drived one myself, but I understand the consept. Have tried a Yamaha 2-stroke 250 in the late 80's, what a crazy bike with almost 50HP, all power located at top RPM! Had a CBR600 myself a few years ago. A bit heavy compared to the NSR of course, but still a nice piece of R-bike. Unfortunately it was "boring" to drive in less than 50mph, the fun started at 80mph, so I had to sell it to keep myself alive Got myself a KTM Duke 125 last year, hoping it would be a nice commuter to work. Sorry to say it was rubbish Indian quality, alot of serious faults already when brand new. Just got my hands on a NX from 1993 who needs a bit attention, but I just love the extreme Honda quality