Hello everybody,

This is a great forum and although it's mostly NSR250's it's also pretty useful for the NSR150SP, it seems 9% of members have the 150! I've found some great info using the search function about my NSR150SP.

At the moment i'm just completing a full respray with new stickers, that was fun!

So, next on my to-do list is the engine. I'm thinking i'll get a full engine rebuild - top and bottom inc. clutch. It's about 5000 baht including parts and labour over here (Thailand) which is very reasonable.

I thought as it's going to be apart i may as well tune the bike for a bit more power. So, i want to fit the NSR250 carb, these are readily available here in Thailand and seem like a good way to go for the NSR150SP.

So, what other parts should i get from the seller when i buy the carb? Is the conversion easy to do? Do i need to cut/modify anything to make the carb fit? By the looks of it i'll need a spacer between the carb inlet and the cylinder? Does anyone have details on this? Maybe i can get it made up by a local company.

Then, there's the exhaust.

I already have this NSR150SP exhaust:

http://www.flickr.com/photos/richardlowe/2921352030/

It wasn't expensive, i'm not a master on the design of 2-stroke exhausts, does this look efficient and able to make good power?

Also, this exhaust is SUPER loud so i have a plan to use the chamber but then keep the original silencer, so a longer 'stinger' pipe would need to be made between the chamber and the silencer. Will this have a positive or negative effect on the system and also what diameter tube should i use for this?

I hope someone can help me on all of this,
Kind regards,
_________________
I love my Honda NSR150SP

Hi,

Why would you want a quiet exhaust in Thailand; the police clap when I go past.
If you want to fit a different carb; which is certainly the way to go, then I would fit a pj/pwk.
In Thailand you have Tyga and they make a carb insulator for this type of carb - about 1200 baht I think. I also happen to have a
pwk39 which I bought second hand. They are about 10K new and if you wanted mine you could have it for what I paid for it - about 3.5K. I will probably have jets and needles in the next couple of months as well.
The 250 carb will certainly work well but where to get the adapter? Maybe somebody else knows?
I don't think tyga stock the exhausts anymore but Matt would be able to tell you if the one you have is good or not from the photo???
You could also fit the front master cylinder from the 250 as well. The 250's are really cheap over here - 30/40k. That would be like swapping everything.
The 150 cylinders can be ported considerably but if you want to ask Tyga; you will have to join the queue (I am next). I've just bought a book and a dremmel to give it a bash myself - what could go wrong.
Let me know if you want the carb; I am going to the Uk on Thursday and could bring back with me on Tuesday ish.
You are also welcome to the next 'nsr-world' meeting in Peppermint agogo The last one had a poor turn out - Me and Matt.
_________________
mc18 F3, mc21 300, mc21ish sp, mc21/28ish.
cbr929, RC30, tdr250, rvf400, wave, gyro, joker.

Hi David,

Thanks for your response, good to hear from a fellow nsr owner over here. As for the noise, i don't like the girls whining about the noise plus i plan to do a few long trips ...

Thanks for the offer of your pwk39, that's a big old carb, i think i'll stick with the 32mm for now though for everyday use. How about other 2 strokes we have here in thailand? I know the Kawa KR150 has a 28mm but how about the Yamaha TZM, Honda LS and the like, do you know any that have either a 30 or 32mm PJ?

Thanks for the advice on the 250 master cylinder, is this a direct replacement for the old one? And can it be used with the original disc/caliper set-up? If so that'd be great as already have the braided lines but could do with a new master cylinder.

I read a bit about the porting, it seems there's quite a bit that can be done, like you say Tyga has a queue and i don't know of any other shops here in Bangkok that can do this work, any suggestions? Infact, i need to find a shop to do my rebuild anyway, i've got sick of the shop i use as they took the P*** one too many times, lol.

Thanks for the invite to the NSR meet, where's peppermint?

Cheers!

returnofthemist wrote:
As for the noise, i don't like the girls whining about the noise...

That's easy to sort... Get a different girl!

#1. Bike
#2. Food
#3. Sangsom
#4. More food
#5. Girl...s!

32mm carb is the way to go. 25mm spacer between the inlet manifold and crankcase can be made out of a block of nylon. It's just to space the carb upwards and away from the crankcase. You'll need an NSR250 inlet manifold cut in half, and a custom throttle cable. Also need the parts from both left and right carb to make one good carb suitable for the 150, but if I recall correctly, you don't need anything else.

NSR150 base jetting works well in the 250 carb to get you started.
_________________
Andy.
NSR-WORLD.COM

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You allow girls on the back of your bike!

I don't know about other manufacturers, only really owned Hondas. I do have a TDR but that's because they are a little crazy. Has small carbs though.

I think with a decent exhaust and carb, you will release enough power and then the porting can be done later. Who else could do it; I don't know. The cylinders are really cheap and available.

I will have some free 250 carbs available but no time to hunt them out - just been told I'm needed in Singapore next week and still need to go to the UK. My free time after I've typed this will be measured in minutes. If you're still looking when I come back, I will find them for you. Also have jets coming out of my arse if Andy's suggestion doesn't work - sure it will though

From what I know, the 250 master should be a straight fit. Think the 250 is 14mm which will be a couple more than the 150 Red Baron in Bangkok sell some really cheap original brembo stuff and Bangkok is full of fake stuff It would only cost a few baht to find out but can't imagine why it wouldn't work with the original callipers etc.

Bangkok is the place to find parts. I guess you have looked on mocyc.com - shows you what bikes are over here. Some cheap bikes and parts on there.

If you insist on carrying the misses, I believe YSS make shocks for the 150 over here. Don't know what they are like but very cheap and always good to support Thailand.

You don't need a shop to do the rebuild; give it a bash. Bet you live in a condo though and can't fit the bike in the elevator.

Peppermint is in walking street Pattaya. It's somebody's favourite bar. It's also above another bar where you can find lots of 'ladies' called Billy if you know what I mean. Bet they are good on bikes though.

What are you doing over here?
_________________
mc18 F3, mc21 300, mc21ish sp, mc21/28ish.
cbr929, RC30, tdr250, rvf400, wave, gyro, joker.

Andy and David, thanks for your info, that's really helpful , i was thinking i'd never find a decent resource for the NSR150SP but i've now found it!

Andy, sounds like you've got your priorities right The 32mm carb conversion sounds reasonably straight forward, i'll be getting both carbs and i'll make sure i get the inlet as well. Is it possible to use the throttle cable from the NSR 250 or from the 150? If not, where can i get the custom cable? I think i can manage the block of nylon and already have a cone filter to go on the carb.

David, free carbs sounds like a steal! When are you going to be out this way again? I think i'll take your advice on the 250 14mm master cylinder. There's loads of parts here in Bangkok, like you say mocyc.com is a good resource and there's loads of shops in the hua lampong/chula area. I'm doing the usual teaching over here and yes i live in a condo and can't get the bike in my room!

Oh yeah, another question i have is about the RC valve, i have both a NSR150SP and a NSR150RR, i've managed to get the NSR150RR RC valve back to life by stripping it down and giving the potentiometer a good cleaning but the NSR150SP potentiometer isn't having it. So, my question is, are the 250 and 150 RC valves basically the same? I know the housings and gears are different but i'm thinking the potentiometers are the same, if so, i pick up a NSR250 RC valve and rob it of it's internals,

Manys thanks,

Do you servo? Surely you could pick up an new RC Valve servo from Red Baron for a few hundred Baht? I'm not sure if the RC Valve controller is part of the CDI (like the later 250's) or a separate box, but it should be very cheap to fix over there.

You're probably best off modifying an NSR250 throttle cable. Thinking about it, you may not even need to mod' it. Just use a 250 throttle tube, housing and cable and it should all be fine. I doubt you'll need the return/closer cable, only the opener. You'll just need to get a 150 and 250 cable side-by-side and have a measure up. You may need to de-solder the carburettor end of the 250 cable and shorten it back to a similar length of the 150 cable. Should be obvious when you have the parts in front of you as long as there isn't too much Sangsom missing out of the bottle that should also be on the table in front of you!

One thing though, you need to find out why the Valves stopped working, else it will probably just happen again. Prime culprit on the 250's is carbon deposits on the Valve flaps. It causes them to jam and overload/burn out the controller PCB on the 250.
_________________
Andy.
NSR-WORLD.COM

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The servos are about 2000 baht which is not a lot but still worth getting as used one as they're only 500 baht. I think the reason for the servo not working is just a lack of maintenance by thai people, they tend to run bikes into the ground and only fix the things necessary to actually make the bike go forward (not at any great speed). The flaps move freely, you're right about the CDI, the early NSR150RR had a seperate RC valve controller box wheras the later NSR150SP has it built into the CDI.

Thanks for the info about the cables, i'll probably just get as much as i can when i buy the carbs, i.e throttle cable/holder, inlet etc. etc. and see how i get on.

I'll save the sangsom for the weekend, beer for during the week!

Andy, did you check out my exhaust in my first post, what do you think about it, does it look like the mide section/cones are the right angles/length to make a power increase? And how about that stinger, what diameter tube should i go for?

Cheers,

Anything's better than the boat anchor Honda Thailand slung under the 150! It's probaly a DBS or a rip off of one of his pipes anyway, so it'll most likely be fine.

You used to be able to buy bigger (possibly) quieter silencers that would fit those pipes in BigC! Not sure if you still can, but there's bound to be something out there suitable. You will probably find that it's the same, or similar, bolt pattern to Honda/Jha. I'd pick up an old Jha silencer or similar next time you are at Red Baron and get that on it. Easy enough to re-pack too. It's always going to be relatively loud though, due to the single skin of the chamber... it'll be even louder with the 250 carb and cone filter!
_________________
Andy.
NSR-WORLD.COM

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Sounds good, so i'll stick with the exhaust. I'm thinking of using the chamber and then linking the chamber to my existing silencer with a new stinger pipe, my existing silencer is in good shape and repackable as well. And the silencer pictured is real low and looks crap that low down, i want to keep the original footpeg mounting point.

How about the diameter of the stinger? I'm guessing the diameter will affect back pressure so is quite important, maybe i will be safe if i go for the original Honda diameter?

I know what you mean about it being loud, i can live with the carb/filter and tinny single skin but like to have a decent size silencer.

Btw, what is DBS?

Did you used to live out here in Thailand? How did you like it?

Cheers,

DBS (Deang Bangsai) is probably Thailand's #1 pipe builder, but you can't go to him direct, as he keeps a very low profile since the authorities decided that loud pipes were a national crime!



Many of the pipes hanging off the ceilings of the speed shops (both 2 and 4 stroke) will have the DBS badge on, or will be a copy of his designs. His pipes are on just about all the fastest drag bikes. The cans have the same cast 3-bolt mount as the Honda/HRC/Jha silencers.

Pipe building/modifying isn't something to take lightly, but I'm no pipe builder so I'm keeping out of what to do in that respect! Have to use your best judgement.

I used to live in Happy-a-Go-Go, Pattaya!
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

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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Ah, it's all clear now! I think i'll just try to use as much of the original Honda stinger pipe as possible and see how i get on, there's nothing to lose!

How about that nylon block for the NSR250 carb conversion Andy? Is it needed for clearance purposes or is it to help the carburettor work properly?

Also, i have a bit of a stutter/hesitation at about 5-6000 rpm on my NSR150RR, i'm going to rebuild the carb, fingers crossed this will clear it up,

Cheers!

Hello,

So, the NSR150SP is coming along well, looking pretty amazing with my handy work of a home brew respray, you really couldn't tell, it's good, trust me,

So, i have come across somewhat of a problem, it appears my front shocks have an issue. Well, it's like this, the right of the two is perfect, but, the left has a rust patch which protrudes about 5mm above the oil seal, i presume that means the left shock can no longer hold any oil? This is not good,

But, i have a spare pair of front shocks from a NSR150RR, are these of the same specification and fitment?? Fingers crossed, i hope so!

If so, what grade oil would you guys suggest, i'm not a big guy,

Thanks all,

Hmm, those MC21s look tempting but Bangkok traffic just doesn't work out,