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4nx 4un
Posted: Thu Dec 03, 2020 8:38 pm
by markymark
can any one tell me what the difference is between a 4nx engine and a 4un
is it to with the wiring from the engine or the cdi / ecu units.
Re: 4nx 4un
Posted: Thu Dec 03, 2020 10:10 pm
by dicky
4NX is the Japanese TRX.
It has different front brake calipers, a restrictor built into the speedo that triggers a cut-out on the CDI, and different carbs. Thats about it.
The engines are the same as 4UN and are complete plug and play swappable.
The only difference is the numbers stamped on the crankcase.
Re: 4nx 4un
Posted: Thu Dec 03, 2020 10:55 pm
by markymark
dicky wrote:4NX is the Japanese TRX.
It has different front brake calipers, a restrictor built into the speedo that triggers a cut-out on the CDI, and different carbs. Thats about it.
The engines are the same as 4UN and are complete plug and play swappable.
The only difference is the numbers stamped on the crankcase.
can i still use my 4un carbs on a 4nx.
Re: 4nx 4un
Posted: Thu Dec 03, 2020 11:49 pm
by dicky
Yes, but if you get a 4NX with original carbs you might want to keep them.
They have an accelerator pump which could spice things up a bit on a twisty road.
You do not want to use the 4NX CDI as it is restricted.
Same connectors as the 4UN so very simple to swap.
Re: 4nx 4un
Posted: Thu Dec 10, 2020 10:43 am
by gurunik
Hey Dicky...... As font of Knowledge on the JDM's, let's talk carb kits for a 95 JDM. What should I be looking for? Have done done all that can be done on the rest, springs, air valve cover, pipes, ignitech (best bang for buck ever) pads, lines, shiny bits, now to delve into the last cave. Carbies. Being a 4nx, what parts suit? Real hard to get a handle on this. All fine for the 96 crew.... 95 just a tad different in the shit you way.
Re: 4nx 4un
Posted: Thu Dec 10, 2020 6:35 pm
by Snod Blatter
As far as I know it's all the same, they're just BDST38s with the accelerator pump fitted. The only part that may be different is the diaphragm spring so I reused the originals.
Re: 4nx 4un
Posted: Thu Dec 10, 2020 11:12 pm
by dicky
What Snod said, they are BDST's with an accelerator pump.
You can get vitron seal kits from Litetek in Thailand to refurb them, or replace them with FCR's or TDMR's if you've got more money than sense.
I'd stick with the pumped BDST's for street use. They have a bit more kick over the standard carbs, but none of the hassle of a direct slide carb.
Just my opinion as I'm not a fan of FCR's et al on street bikes.