NX250 Thread -- official ADV owners manual

Well, since it is air filter foam I suspect it will work quite well as an air filter. Plus at $13 for enough to make 6 or 8 of them, who cares if it only lasts a year. It should last a bit longer than that though. I supose if you could back it with some screen, but i'm not concerned.

Hey guys!

It seems that I am going to have to split the crankcase to see what's up with my transmission. This is my daily commuter so I want to be done as quickly as possible.

I am wondering what gaskets I have to replace when putting it back together.

Clutch cover gasket must be replaced
Crankcase gasket must be replaced
Head gasket was metallic and seemed reusable, what do you think?
In there anything between the cylinder and the crankcase ?
Anything for the alternator cover?

Do I have to order a whole kit or can I maybe get away with ordering the essentials?

Also, my original question is still valid : what makes it really hard to shift from N to 2, but does not affect anything else?

Thank you Mito,

I found the parts eventually at a Honda dealer in Romania, they just arrived today so we're going to the garage after work to see what's what and since we're opening her up, also clean whatever needs cleaning (carb, air filter, check the coolant and look at the wiring. The parts I bought were as @fikse said: Main Jet and the intake, plus I bought a new gasket. Hope everything goes well, I'll tell you how it goes after the upgrade

I also got a XTZ750 Super Tenere which incidentally will also go under a little bit of electrical surgery today, as the charging of the battery is a little "absent"

Thanks again!

You can't reuse the head gasket, it deforms as you torque the head. You also need to replace the base gasket between cylinder and the crankcase. There is an oil pump gasket that I'd recommend changing too, and the alternator cover has a gasket.

I have a complete NX250 transmission here if you find something you need.

Hey guys,

Last night we changed the parts necessary for the power upgrade for the restricted model NX250 (Germany) and I was wondering if there are any specifications regarding the tuning of the carburetor. I'm thinking since there's a bigger main jet and the intake is larger, some more adjustments are in order. Do you have any suggestions regarding the settings of the carb for the new configuration?

Thanks!

Well, too bad I already did reuse it, twice.. Both cases were unexpected head removals due to misplaced/broken cam chain guide (plastic piece). I did not feel any difference with the reused gasket, and my coolant seems free of contaminants, but what do I know..

Complete transmission sounds good. I sincerely hope that when I open the sucker up I can SEE what the hell is wrong with it. It just happened one morning, which is ridiculous, and I keep asking the same question :

What makes it really hard to shift from N (or 1) to 2 but not affect anything else?

I honestly have no idea what might be wrong inside. All of my experience working on bikes comes from this particular one and the crankcase is still a virgin, so its a black box for me.

So, having a complete working transmission at hand, any ideas on what might be wrong? How is the N to 2 mechanism any different than all the other shifts, which do work flawlessly? N to 1 is also perfect, it is just N to 2 (or 1 to 2) that is stubborn.

I have been riding the bike like this (it does shift to 2 after a few tries) and I don't even know what kind of damage I might be doing.

the only difference as far as I know is the setting of the pilot screw. With the restricted model (GII type) you have to back it out 2 5/8 turns, the unrestricted modol 1 1/2 turns.

Thank you, will try that, although I'm not keen on dismantling the whole labyrinth again :) Hope it will make a difference, it felt a bit underpowered this morning...

Ok, so you can re-use it, and it may work...but it's not wise. I guess you could re-use a condom too if you wanted to.

Your shifting problem is probably the shift drum, or maybe a shift fork. The slot in the shift drum could be worn a bit, causing the shift fork to catch as it tries to move the gears. Or, the shift fork could be bent slightly causing the same problem. I'll clean up the gears I have and if you find anything you need we can make a deal.

yeah, no chance to operate the pilot screw - not even with this special carb tool I bought



There is simply not enough space between the carb and the starter motor. Luckily the standard setting of 1 1/2 turns fitts pretty well, so you don´t have to play around

there is a way to play with the carb screw

take the 4.5mm from one of those

and place it under the carb screw
is a perfect fit and you can turn it with your fingers

Is there a reason no one has used a cone filter? I understand that the airbox would beed to modified or eliminated but there has been so much talk about retrofitting the old filter housing when it seems like an easy fix to replace it with a different unit all together.

I got some parts in the mail so this weekend I went to work resurrecting (2x) the nx.

Depending on what you are doing with the bike that solution is an option, but there are drawbacks.

1. It would likely cause the carb jetting to need significant change.

2. If you are really using the bike as a dual sport it is far more exposed to dust and dirt.

3. If you are REALLY using the bike as a dual sport and ever need to cross a stream it would be at much greater risk of getting water sucked in.

For all the reason's muddyrabbit gave above, and in addition...

In addition to mRbbt, if you ride in the rain, the cone filters suck water off the rear wheel...also, that's a tight area for a 'large' filter such as a 3" cone..

The NX250 likes to breathe, it's a revolution speed lover(rpm's) and it's pretty choked out with the stock paper panel filter..but with the shrink wrapped frame/airbox/shock combo....there isn't much volume to 'fit' a cone of the appropriate size/flow, and still have it in the proper area.

Also, it's vulnerable to theft, exposed to elements of weather(some cause engine death), and most of all...
HOURS of work and 'customization'?

Taking out the airbox is a heck of a chore...but that's also called 'doing it the hard way'...






The K&N #33-2633 Daihatsu Mira Turbo (spec)
air filter was a <s> 100%</s> 98.9% direct fit.

There isn't going to be much of a quicker/easier airbox modification than using the 33-2633 instead of OEM.

You only have to trim about 5mm off one end....the side to side clearance is exactly perfect..
It IS that perfect of a fit.
Excuse me while i take some time to sort out, photo, and post the results..


But as seen,(in my hands, not yet posted)
the 33-2633 can be used without the stock filter 'surround'...

you use a razor knife to cut one end, the rubber surround of the Mira filter is about 1/4 inch too long to 'drop in', but with firm pressure and a razor sharp knife, it is EASY to trim up...

just need a few flanges (keepers)...
and it should drop into the recess in the stock airbox..

When sorted out, going to repost it on the previously discussed page of the thread, page#365....


Working on it now...

details are coming...i've finally got it sorted...now gotta find time to post it up..

Yeah, ripping out the airbox would take longer than what I did.

I got my NX engine tore down. Sorry, but I didn't photo document the disassembly. I was too focused on labeling and marking everything so I'd know how it goes back together. I suppose photos would help with that also.

Here's the crankshaft, with the stripped cam chain drive teeth.






Here's the crankcase, with the transmission. Getting the cases split isn't too hard. The most difficult part is getting the clutch retaining nut and the primary drive nut removed. Both of them are peened, and require you to lock the shaft in some way or another. I used a piece of aluminum between the clutch and the primary drive teeth.



I bought an NX250 lower end engine to try to get lucky on a good crankshaft, but it turns out that the small end of the crank rod is out of round. Now I'm going to try to find a shop that can press the crank apart and try to make two bad cranks into one good one.

I didn't mean this to come off as a critique. This is in fact the most thrifty air cleaner replacement idea I have seen so far. I was merely curious and I had read post after post about air cleaner issues.

On a different subject, I'm putting my nx back together. I'm following the manual but I don't trust the tensioner one bit. What I want to know is: after installing the tensioner according to the steps outlined in the manual, is it a bad idea to give the tensioner an extra little crank, say 1/2 turn to advance the tensioner and tighten the chain a little further? My last tensioner failed and left me busted. Anyone do this? I am also aware of the "manual override" tensioner fix that has been suggested elsewhere.

Didn't take it that way. Just commenting as I had considered removing the air box to install the gsxr shock, and it looked like a pita.

The wife says I have too many in the stable. I never take the Nixie off road like I'd planned to when I bought it, so maybe someone else can use it as it was designed to be used. Other than the street tires and air horn, it's bone-stock.

Ebay item # 271027960442 Cheers, Doug

Howdy fellow NX'ers.....I've been searching ADV and the all over the internet and keep coming up short...

Can anyone share luggage or rack solutions that have worked for them? I'd like to have panniers to keep the weight low. I do not have the stock rear rack mounted on my bike - I'm hoping to go bigger/wider with my rack platform and have pannier frames off the sides.

Thank for any advice...