Hi all, I'm new to the forum so shouts out to all the other members!

I have a 1985 NS250R MC11 with about 20,000 kms on it. I haven't been riding it much during the pandemic, but used fuel stabilizer and a battery tender and would start it often. I had to go out of town for a few months over the winter and when I returned I kicked it over and it fired up but soon kind of bogged out and died. I haven't been able to restart and when I try to kick it over there is a ticking noise coming from what i believe to be the fuel pump (cylinder shaped bolted to the bottom of the frame on the right side).
I changed the fuel filter as I think it was original, but it didn't help.
I'll try to upload a picture but the file is too large. If anyone is interested in seeing a short video I could send you a google link.
Does anyone have experience with this clicking? Any help would be greatly appreciated.
Thanks Wayne

I guess it would be the obvious fault finding. Check the plugs for a spark, swap plugs over or replace, Ensure the battery is fully charged, ideally with a smart charger or test with a meter. I assume none of the connectors have been disconnected. I'm not familiar with MC11s, but does the ATAC valve have a servo?

Have you read this link as well http://www.nsr-world.com/workshop/wiring/electrex-fault-finder/Electrex_fault_finding.pdf
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Why do things simply when you can complicate them

Hello Wayne, and welcome to NSR-WORLD.COM

I'm sorry I can't offer anything more than RobH, but please keep us updated, and hopefully post some more NS250R content later. It's very rare to see anything about them, even here.
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Andy.
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Another NS250R ('84) Owner Here - ja... not many of these around!

I have the same problem as Wayne on the resurrection I am trying to perform on an NS250 that sat many years; fuel pump.
Looking at the respective positions of the components and applying the principles of gravity, would it not be reasonable to assume the fuel pump could be bypassed/eliminated completely?

Currently the goal is to make it run before staring in on any cosmetics (it needs bodywork repairs and paint). If it runs fine and doesn't need crank seals or something 'engine out and apart' major, I'll go ahead with making it pretty. Otherwise it goes down the road.

Other than a few details, the bike is essentially unaltered or modified with about 19K km on the dial:


Regards,
WPW

I was quite surprised to hear the NS250 has a fuel pump. The carbs are very similar to the NSR250 items, which work perfectly well without a pump, but maybe the height and/or installation angle on the NS necessitates it?! The problem is you could potentially run very lean if they do indeed require greater fuel pressure at higher RPM.

As I said to Wayne, I wish I could be of some help, but just have zero experience with the NS. I'd love to see more content on them though. I hope you stick with it. I might see if I can find a genuine service manual and scan it for the site.
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Andy.
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Nice bike - what year is it ?

I’m guessing around 1983 but could be well wrong

Hi Wayne, It's a 1984 - first year NS.

Andy, my thoughts exactly - I suspect it was a bit of over-engineering. The fuel pump is definitely correct for the NS; there is a special tab cast in the frame to mount it on, there is a molded rubber cushion, and the lines have dedicated clips and retainers to hold them in place. They look like this one, a common 4-stroke pump for the same years:
https://m.media-amazon.com/images/I/71b6FlJgG0S._AC_UF894,1000_QL80_.jpg

I studied the system, slept on it 2 nights in a row, and have decided to run the fuel line directly; it would only be about 8 inches long, and could be routed so it's down-hill all the way with no loops or 'traps' to prevent vapor-locks. I would think that the NSR requires even more fuel than the NS. I will include the old pump and sundries in case someone in the future decides to do a Concourse-accurate restoration.

Warren

The race bike, based on the MC11, is gravity fed.


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Andy.
NSR-WORLD.COM

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Now you're tempting me! That spaghetti monster intake area cleaned up nicely - something on that order was in the back of my mind when I was extracting the stockers wishing my fingers bent backwards.

Deep thoughts ... on the '85 RS250R, it looks like Honda just used single petcock/gravity feed (with 8mm fuel line) and it worked fine. On a stock motor, the 6mm line should do nicely. Now if I can just leave those VM Mikuni's on the shelf...

In case you missed it on the other thread, I've ordered an NS250R Service Manual from Japan.

This should really be in the NS Discussion section, so I will PM Wayne5007 and move it. Not banishing you to the dark areas, but just like to keep things organised. As I say, I'd dearly love to see more NS content, and it's easier the find information if it's kept in the correct areas.

I'll be learning with you guys once the Service Manual arrives!
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Andy.
NSR-WORLD.COM

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Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

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