Nsr 150 Sp Running Poorly In Midrange.. Need Some Advice

[Dutchbike]

Since i had the engine of my NSR 150 SP overhauled, ( complete new top end, crankshaftbearings etc etc)it's not running as it did before.

In midrange 3500 rpm until 6000 rpm it's running very rough,and it's stuttering ( that is with about 1/4 throtlle opening) when i open it up more it's struggeling to catch rpm's but once the engine gets in that higher rpm's.. 6500 rpm and higher it runs well and there's plenty of power, when i get to 9500/10.000 rpm,it just refuses to go higher ( redline starts at 11.000rpm)

I've tried different main jets # 152 (=stock) # 155 # 158 but that's not making a lot of difference.

After the overhaul i fitted a Tyga exhaust system and i first thought that could haved caused it. but today i went back for a complete stock setup ( exhaust) ( except a # 155 main jet) and the "problem" is still there.

When the bike is stationary and i rev it, it runs fine all the way in the rpm range.( but also here not much higher then 10.000 rpm)

The bike got a new OEM cdi, new ignition coil, a fresh spark plug (NGK B-9-ECS)

The RC valves are working well and are adjusted as they should be.

The needle in the carb is non adjustable so i can't "fiddle" with that. but will replace the needle as a last try, and then i'm out of options so any suggestions what might could cause this "problem" are welcome. The way it drives now it's like all or nothing. I know, a 2 stroke will never be very smooth in the lower rpm's but it was much better before.My other 2 stroke bikes: a Yamaha TZM and a TZR ( similair engine designs as the NSR) are more civilized in the lower rpm's.

Mayby a NSR is a more delicate design and needs a perfect set-up, (for which i'm looking for)

[bikkalad]

Try having a look at the reed valve ??? Carb off and inlet manifold off pull them out and check...... May have a problem there ........ Crap in the float bowl??? Needle valve??? Hope this helps

[bikkalad]

Ht cap problem ??? Bad earth??? Woodruff key broken on crank shaft , the key way for magneto flywheel??? Can't think of anything more hope this helps

[Dutchbike]

Thanks bikkalad, will have a go with the carb first, cleaning it and replace the needle. the reeds where fine ( stiff ) when i put everything back together.

I also replaced all the seals in the carb but still suspect the carb causing the "problem" when it would be an ignition problem it should appear in all revs ?? off to my workshop now.

[KRS1]

Sounds exactly like a RC valve adjustment problem, even though it may appear to be within tolerance, even 1 freaking millimeter can throw off performance.

If you cant go past 10k, it sounds like the rc valves arent opening far enough and is choking. Adjusted properly your bike should have 2 powerbands - one at around 5500 rpm and another around 9500 rpm

I hate setting the RC valves, if you disconnect the motor and turn the valve fully open by hand and it still doesnt go past 10k rpm, the actual RC valves are probably damaged and wont allow you to set the servo/motor accurately to tolerance no matter how long you try, because theyre wiggling internally or have chunks taken out of them allowing too much exhaust to pass.

What i do if the rc valves are toast is...i ride around with a couple of wrenches in my pocket and adjust them when pulled over and try to get it as close as possible.

Setting the airscrew can also have a similar effect but at a lower level, you'll lose about 15% performance when not set properly. Install the stock slow jet if you have it I think it was either 42 or 45.

[Dutchbike]

Even more things to check ha ha, well the new Cylinder came with new RC valves so i hope there not already toasted, i already did some adjustments to the RC valve timing but my main problem is in the midrange ( stuttering and running very rough)and in that midrange the RC valves are still closed.

before the overhaul the engine also didn't got into the redline but the old RC valves weren't damaged.

just to get things clear, RC valve timing: when the engine runs stationary the mark on the pulley shoud be on the H mark of the cylinder,( RC valves fully openend) when you rev it they close, and at about 6.5 / 7 K they open again.

That's what the workshop manual tells.

[KRS1]

The H mark....i still have nightmares setting it to the H mark, right when i think its set... it goes and moves on me do to a stretched cable....no more rc valves i tell you, no more...ever !

There's a range of a few millimeters for that H mark, just a 1 millimeter deviation can be a night and day difference.

How many teeth is the front sprocket? a 16 tooth up front will also feel similar to what your describing. Stock i believe is 15, but 14 is real nice for low to mid transition.

[Dutchbike]

@ KRS1 sprockets: front 14T rear 40T Yeah those RC valves.... i think the YPVS from Yamaha is far more reliable and they seem easier to adjust ( although also working with cables)

Update: this afternoon i took out the carb and cleaned it with compressed air, i changed the main jet for the stock size (#152) ( the slow jet is # 42) I wrote that you can't "fiddle; with the postion of the needle, but there's a trick: you can raise it a bit by putting a small washer under the needle (1 mm) before putting the needle in the throttle valve ( red it on a NSR site) I did that before, and now removed that washer again, reset the airscrew to stock setting ( from fully closed position 2 turns out) and finaly fitted the ( removed) "snorkel" from the airbox.

Took it out on a testride and it seem to have worked,it runs much better in midrange and now revs up to 11.000 rpm. don't know excatly what did the trick ( removing the washer and by that lowering the needle or changing the main jet???) for now i will leave it at this set up and do some more driving. But at some point i'm sure i want to try the Tyga exhaust again, i always was tolded that if you change the exhaust on a 2stroke for a "faster one" you have to change the main jet for a bigger one, but mayby more modifications are needed to make it run well ( like fitting a performance airfilter) well, working on those 2 strokes is a learning process and i'm still learning.

[KRS1]

Sounds like it was running too rich, since raising the needle will richen it, combined with the larger jet couldve have been overly rich ? Do you remember how many turns out the air screw was before you readjusted it?

When you pulled the slide from the carb, did it feel like a solid chunk or was it questionably light? The real ones have brass slides, the fake ones are all silver colored on top. The fake npro carbs have really light slides and the bypass hole etc...havent passed through an ultrasonic cleaner during counterfeiting to reduce turbulence.

The fake carbs have serial numbers stamped on, authentic ones are laser etched, each character will be composed of many small dots to draw out a letter/number. But not really sure whether the earlier versions were also laser etched.

The slides in the first generation npro carbs and the new ones you can buy today, have different air flow indicated by the stamp on the slide.

Original Keihin jets are chamfered around the hole to reduce turbulence, fake jets dont have any chamfering, so it wont flow like a real one. But honestly i havent really been able to tell any difference.

Glad you got it sorted out, when i hear 'H mark' i cringe in fear...lol

[Dutchbike]

Sounds like it was running too rich, since raising the needle will richen it, combined with the larger jet couldve have been overly rich ? Do you remember how many turns out the air screw was before you readjusted it?

When you pulled the slide from the carb, did it feel like a solid chunk or was it questionably light? The real ones have brass slides, the fake ones are all silver colored on top. The fake npro carbs have really light slides and the bypass hole etc...havent passed through an ultrasonic cleaner during counterfeiting to reduce turbulence.

The fake carbs have serial numbers stamped on, authentic ones are laser etched, each character will be composed of many small dots to draw out a letter/number. But not really sure whether the earlier versions were also laser etched.

The slides in the first generation npro carbs and the new ones you can buy today, have different air flow indicated by the stamp on the slide.

Original Keihin jets are chamfered around the hole to reduce turbulence, fake jets dont have any chamfering, so it wont flow like a real one. But honestly i havent really been able to tell any difference.

Glad you got it sorted out, when i hear 'H mark' i cringe in fear...lol

H mark, H mark, H mark, H mark, H mark, H Mark haha.

You seem to know quite a lot about these NSR's.

The carb is 100% an original one. I,ve tried once one of these copie ones on a TZR ( luckley i could get a refund).

b.t.w. what's excatly the function of the intake chamber ( the black "box" on the manifold??)

Thanks KRS1 funny i'm getting advice all the way from California.

[KRS1]

No not the H word !...lol...yeah those 150's are a treat to ride while in Thailand, not many places in the world you can ride them...

If you've ever ridden a totally built NSR150 motor - it's a sick experience, which many wouldn't believe unless they ride one for themselves.

That black box tricks the intake velocity into thinking the intake tract is longer than it really is...makes the throttle smoother, but less responsive. Its a mild form of restriction.

If you haven't changed it yet, try changing the pulser sensor (thats what its called in thai: pulser) next to the flywheel inside the engine cover. It's cheap about 200 baht and your bike will accelerate smoother if its never been changed. It sends the signal to the cdi, then to the sparkplug to give spark. Sometimes they get filed down to adjust the timing and can also cause an erratic powerband. - This use to be Somchai's favorite garage trick.

Cant wait to get back and ride thailand again once it gets cool, nothing like it anywhere in the world. Been there for 16 years and needed a little break from too much chemical whiskey, toxic cigarettes and loose women....i sure aint missing the heat and humidity though !

[kiske]

I had the same pre-powerband stutter when I switched to a racing pipe - some carb tuning helped, but in the end I just switched to a PWK30mm and it now runs perfect.

If it's not the carb, I second the power-valve timing, those cables are a pain in the ass. KIPS had the better idea for PVS imo.

[Dutchbike]

I had the same pre-powerband stutter when I switched to a racing pipe - some carb tuning helped, but in the end I just switched to a PWK30mm and it now runs perfect.

If it's not the carb, I second the power-valve timing, those cables are a pain in the ass. KIPS had the better idea for PVS imo.

With fitting a PWK carb i asume you ditched the autolube ( oilpump) and use pre-mix.

You still got the airbox or fitted a performance airfilter??

I was already afraid that a Tyga exhaust ( or other brand racing exhaust) would need more adjustments then rejetting to make the bike run well.

I,ve red that some people are using NSR 250 carbs ( 1 of the 2) and that seems to be also a big improvement.

I want to keep the autolube, so that narrows the possibilities.

For now i'm happy i got it running well again, and have some more rides, mayby in the future will give the "racing" exhaust another try or it will come up in the adds

[Dutchbike]

When it looked like it was end good all good things did change 2day and the story has just begun.

Today went for a ride and while on a nice stretch of empty road i openend it up, reached 170 km/h, off the throttle and speeding up again good response, enough, while slowing down to cruising speed, suddenly no more power ... O no... pulled out to the side of the road and the engine just died on me, pushing it into a the shadow took off my helmet and jacket to check it, i always carry some tools and spare parts ( sparkplug) and i thought ( hoped) that, that ( a dirty sparkplug) was the "problem" try to start it and no more movement in the kickstarter O No... a stuck piston #*!#^*!!!

Luckley help ( my Thai brother in law and his pick up truck) was just a phone call away, in 45 minutes he was at the spot and we lifted the bike in the back, of course he didn't took any ropes to secure the bike so i sat in the back,preventing the bike from falling in the corners.

During that ride of shame i had all the time to think what could have caused it , poor lubrication??? running to lean??? or something more serious down below in the engine??? dropped the bike off at the Honda dealer who did the overhaul ( top-end, crankshaft bearing, connecting rod etc) after they did the overhaul, i installed the engine and brought the whole bike there so they could start it up and do the adjustments, in that way ( they tolded that) they could give me a sort of warranty on the overhaul) well it's time to put that warranty to the test, told them not to touch the bike, untill i come back with my wife for the nessacsary translations. that will be tomorrow.

After i got the bike back from the Honda dealer, i readjusted it a bit ( RC valves, jetting) and the first few 100km's drove it very mild, didn't change anything major, also i double checked the adjustment of the ( new) oilpump.

The rest of the story is in the previous posts.

After my brother in law dropped my of at my house , i took out my TZM 150 and made my ride after all, just to forget this bad experience, it helped, i'm not giving up on this NSR but do hope that the "warranty"from the Honda dealer is worth something.( but i doubt it)

To be continued........

[KRS1]

Same thing happened to me on a Kawasaki KRR150, broke down in the middle of freaking nowhere, looked left, right, forward, back and all i could see were rice fields. Pushed it about 100 meters and found a bike repair shop that was run out of a house. Gotta love Thailand, shops are everywhere even if its just a box of wrenches, atleast you can be reassured there's help somewhere close. Anyway that bike had a cylinder lifted from an earlier version, but had the wrong piston in it and seized up, had 3 rings when it should have had 2, or the other way around cant remember.

A friends NSR 150 stalled in the same way as yours, in his case the crank bearing seized.

Good luck man, i think you may be better off getting one in better condition - i would have ran away in fear at the taped up CDI...lol

[kiske]

I had the same pre-powerband stutter when I switched to a racing pipe - some carb tuning helped, but in the end I just switched to a PWK30mm and it now runs perfect.

If it's not the carb, I second the power-valve timing, those cables are a pain in the ass. KIPS had the better idea for PVS imo.

With fitting a PWK carb i asume you ditched the autolube ( oilpump) and use pre-mix.

You still got the airbox or fitted a performance airfilter??

I was already afraid that a Tyga exhaust ( or other brand racing exhaust) would need more adjustments then rejetting to make the bike run well.

I,ve red that some people are using NSR 250 carbs ( 1 of the 2) and that seems to be also a big improvement.

I want to keep the autolube, so that narrows the possibilities.

For now i'm happy i got it running well again, and have some more rides, mayby in the future will give the "racing" exhaust another try or it will come up in the adds

I run premix, more for peace of mind, as the bike rarely runs below 9.5krpm. The PWK has the appropiate ports for the pump hose, though. So you can run pump+PWK - the flatslide carb does make a noticable difference.

I scrapped the airbox long ago, and i just run an open carb without air filter.

I'd highly recommend a new exhaust, as the stock exhaust is crazy heavy and has a cat. It's also tuned for low rpm power. I've heard good things about the TYGA exhausts, but they are overpriced. I had mine made by some HRC engi (friend of a friend) - and i'm very impressed. It weighs ALOT less and seems to be tuned for HIGH rpm power. Night and day.

The NSR250carbs require a custom manifol, as they are 32mm. I was considering a 32-36mm pwk, but in the end couldn't be bothered with getting a custom intake built, and hence settled for 30mm (fits the stock).

What NSR is it? SP/RRW/RR?

[kiske]

When it looked like it was end good all good things did change 2day and the story has just begun.

Today went for a ride and while on a nice stretch of empty road i openend it up, reached 170 km/h, off the throttle and speeding up again good response, enough, while slowing down to cruising speed, suddenly no more power ... O no... pulled out to the side of the road and the engine just died on me, pushing it into a the shadow took off my helmet and jacket to check it, i always carry some tools and spare parts ( sparkplug) and i thought ( hoped) that, that ( a dirty sparkplug) was the "problem" try to start it and no more movement in the kickstarter O No... a stuck piston #*!#^*!!!

Luckley help ( my Thai brother in law and his pick up truck) was just a phone call away, in 45 minutes he was at the spot and we lifted the bike in the back, of course he didn't took any ropes to secure the bike so i sat in the back,preventing the bike from falling in the corners.

During that ride of shame i had all the time to think what could have caused it , poor lubrication??? running to lean??? or something more serious down below in the engine??? dropped the bike off at the Honda dealer who did the overhaul ( top-end, crankshaft bearing, connecting rod etc) after they did the overhaul, i installed the engine and brought the whole bike there so they could start it up and do the adjustments, in that way ( they tolded that) they could give me a sort of warranty on the overhaul) well it's time to put that warranty to the test, told them not to touch the bike, untill i come back with my wife for the nessacsary translations. that will be tomorrow.

After i got the bike back from the Honda dealer, i readjusted it a bit ( RC valves, jetting) and the first few 100km's drove it very mild, didn't change anything major, also i double checked the adjustment of the ( new) oilpump.

The rest of the story is in the previous posts.

After my brother in law dropped my of at my house , i took out my TZM 150 and made my ride after all, just to forget this bad experience, it helped, i'm not giving up on this NSR but do hope that the "warranty"from the Honda dealer is worth something.( but i doubt it)

To be continued........

Sucks, this was the reason I switched to premix.

I've seized my little fuc_ker 5 times or so now. One time the wheel locked up at 160kmph on the superhighway, scary stuff.

Anyway, running premix 100% synthetic (ptt challenger is pretty good, veloil is good if you can afford it) has done away with the seizing. I pretty much ride it like I stole it ALL the time, and haven't had another seizure in a while.

Run premix, it's not so bad. For every 200-250baht of gas, chuck in a m150 bottle of oil, easy. You can get away with less, but I like to play it safe. Your mind will be at ease knowing that the bike is getting maximum lubrication at ALL rpm ranges. Smokes a bit more, though.

[Dutchbike]

it's a SP.

5 seizures whoooow.so you have been there too, many guys would have given up on a bike after a second seizure, gotta love those 2 strokes.

my runaround TZR runs on pre-mix, with that bike i had a similair seizure as you described: Locking up at 120km/h indeed scary, and in my case painful.

After that i used premix on that bike, aproxx 1:35 is Shell VSX advance 2T a good 2T oil??? ( adviced by the guys from Tyga)

For the NSR i prefer to keep the autolube, but first have to see what caused the seizure, if it's a lubrication issue i will consider pre-mix for this bike as well.

the complete lubrication system is brand new ( oilpump,tubes,strainers,cable) and it was well adjusted.

Yesterday i went back to the dealer, there still was no movement in de kickstater and the mechanic who did the overhaul was afraid that the crank bearings caused the seizure,( a stuck piston mostly comes loose after cooling down) well, that was your work buddy, so there's a bit of hope about that warranty, my wife made it clear i was not pleased and expect that they will fix it for free.no comment just smiles........

They will start dismantling the engine to find the cause of the seizure, guess i will be making a daily visit to check upon the progress.

[kiske]

That shell advance autolube is what I used to use, it's alright for putting around, but it's not really good enough for spirited use. It's semi-synthetic (I think 30%?)

I highly recommend 'PTT Challenger 2t synthetic 100%' - this stuff is really good, and it's not too expensive. I pay about 250baht for 1L, about double the shell price I guess. (The gas stations don't stock it, you have to buy it from Honda etc. - be weary the gas stations have a challenger 2t bottle, but it's semi-synthetic and piss poor)

It will make a HUGE difference in lubrication and reliability. I haven't had any problems in a long time after switching to that stuff.

You can tell the quality is better just by looking at the two, the shell advance stuff looks like water and is quite thin, the synthetic stuff is almost like a caramel consistency and is a golden brown colour.

[Dutchbike]

That shell advance autolube is what I used to use, it's alright for putting around, but it's not really good enough for spirited use. It's semi-synthetic (I think 30%?)

I highly recommend 'PTT Challenger 2t synthetic 100%' - this stuff is really good, and it's not too expensive. I pay about 250baht for 1L, about double the shell price I guess. (The gas stations don't stock it, you have to buy it from Honda etc. - be weary the gas stations have a challenger 2t bottle, but it's semi-synthetic and piss poor)

It will make a HUGE difference in lubrication and reliability. I haven't had any problems in a long time after switching to that stuff.

You can tell the quality is better just by looking at the two, the shell advance stuff looks like water and is quite thin, the synthetic stuff is almost like a caramel consistency and is a golden brown colour.

Thanks for the advice on the oil, is that Challenger 2T ( being thicker) suitible for autolube?? earlier you mentioned Veloil, is that even better?? I don't mind paying more for 2T oil.

I guess all of the other 2T oils ( from Honda ,Yamaha Castrol etc) are more or less all the same quality (semi synthetic)

Update; Yesterday the dealer called and a bit of good news, the piston and cylinder where fine and didn't caused the seizure, the problem was more below and according to the mechanic the seizure is caused by a faulty connecting rod bearing ( large end side) I only don't see how this could cause a stuck engine? ( mayby the crankpin blocking the crankshaft ??)

Since the overhaul was 3 months ago i will have to pay for the actual parts ( 1400thb) the rest ( labour/gaskets/oil) is for free I can live with that, even with labour rate so cheap, removing a engine from the Frame , totaly take it apart ( seperate the engine crankcases) and rebuilding everything is quite a timeconsuming job, better something for free then nothing.

Also the mechanic tolded that the 2 t flow was a bit poor, i'm not aware of anything you can adjust on the oilpump for more 2t oilflow,other that setting it at the marks.

[kiske]

well, at least it's fixed

Veloil is about 600baht per 1L I think.

All are fine in the autolube system, my friend runs challenger synthetic in the autolube without problems.

I'd suggest running the autolube on max setting IF you stick with shell semi-synthetic, or just use it as is with 100% synethetic.

Where do you live dutch?

[Tankbreather]

Hi Guys... hope you don't mind if I gatecrash this party. I've followed all the posts in this thread and I'm really impressed with all the good advice and wisdom coming forth.

So at the risk of portraying myself as a complete idiot, I'd like to ask ask an out of the ordinary question.

I've got an old 150RR and the RC valve is way past its expiery date.... doesn't perform anywhere near what it's supposed to - in fact I've already disconnected it. I'm not a speed freak so I don't mind not going over 80km/hr. I've set the RC valve to what seems to be an optimum position for upto about 65km/hr, but after that I get a terrible "roughness" coming from the engine. I know it's to do with the RC valve because I've fiddled with the positioning with cause the onset of the roughness to vary. I've got about 4 months left in thailand before I go back home and don't really want to fork out 10k to replace the RC valve setup.

My question (finally) is, is it possible to replace the cylinder with one that does not cater for an RC valve. Or is there some kind of adaptation I can make so that I can take it out completely.

I'll forgive your laughter at my questions, but would really appreciate some serious comments.

[barefoot1988]

sorry for piggyback this thread

anyone had any recommendation for honest mechanics around chiangmai?

my tzm had a seized piston

[Dutchbike]

well, at least it's fixed

Veloil is about 600baht per 1L I think.

All are fine in the autolube system, my friend runs challenger synthetic in the autolube without problems.

I'd suggest running the autolube on max setting IF you stick with shell semi-synthetic, or just use it as is with 100% synethetic.

Where do you live dutch?

I'm located in Buriram province,

I will start to use that Challenger 2T from now on. ( on all my 2 strokes) The ( Chinese/Thai) guy where i buy my Shell 2 T couldn't get it for me, but was helpfull giving me a telephone number from the distributor so i hope i can get a few bottles in the coming week.

The NSR should be ready next week , the mechanic wants to make a few testrides to make it run perfect, well let him have a bit of fun on it, he drives a NSR RR, and is the 2 stroke expert in that workshop.

@ tankbreather,

I'm not an RC valve expert ( mayby KRS1 jumps in)

But non functioning RC valves can be caused be a lot of things (CDI, servo, cables,rc valves faulty) disconnecting the RC valves will make the bike run (in the fully closed postion) well until 6000rpm. when you set them in the fully open postion the bike will run rough in the lower rpm's and should run well in the higher rpm's.

But you mentioned that the bike got very poor performance mayby there are more problems.

Since you don't want to spend to much on the bike, mayby you can have the rc valves replaced ( shouldn't be 9k) or look for a second hand cylinder, i don't now the price of a new servo but i think it's expensive.

I'm not aware of any other cylinder without RC valves which woud fit.

Good luck.

[KRS1]

Hi Guys... hope you don't mind if I gatecrash this party. I've followed all the posts in this thread and I'm really impressed with all the good advice and wisdom coming forth.

So at the risk of portraying myself as a complete idiot, I'd like to ask ask an out of the ordinary question.

I've got an old 150RR and the RC valve is way past its expiery date.... doesn't perform anywhere near what it's supposed to - in fact I've already disconnected it. I'm not a speed freak so I don't mind not going over 80km/hr. I've set the RC valve to what seems to be an optimum position for upto about 65km/hr, but after that I get a terrible "roughness" coming from the engine. I know it's to do with the RC valve because I've fiddled with the positioning with cause the onset of the roughness to vary. I've got about 4 months left in thailand before I go back home and don't really want to fork out 10k to replace the RC valve setup.

My question (finally) is, is it possible to replace the cylinder with one that does not cater for an RC valve. Or is there some kind of adaptation I can make so that I can take it out completely.

I'll forgive your laughter at my questions, but would really appreciate some serious comments.

adjust the airscrew to match the position of the rc valve. Since the rc valve motor isnt moving, and you seem to have it more biased to the closed position, its running richer than it normally would. (indicated by your speed of 65kph then gets rough)

Turn the airscrew in all the way, start bike and keep revving it so it doesnt stall, adjust idle to 3.5k rpm, turn air screw out until bike idles highest - usually somewhere between 2.5-3.75 turns out, readjust idle to around1.1k-1.4k rpm.

If your bike doesnt stall when you turn the airscrew all the way in, your slow jet may be too big.

[bbradsby]

'98 NSR 150sp owner here - i second all the advice on the RC valve positioning. It's critical, and the cable tightening fixings are a bit questionable. But when sorted, and oil pump calibrated AND throttle slack adjusted all as a sequence per the Manual, the bike runs like a stray cat chased by soi dogs!

Am running the Mobil Extra 2T Synthetic in the autolube pump, and it runs very happily at high rpm, and doesnt smoke after warm-up.

[Semper]

So where is the locking nut and the adjuster? On my bike, there is nothing to adjust on the right hand cable.

[bbradsby]

Normal - the front cable has a spring and flange to maintain tension on the pulley. The rear adjuster has the adjuster nut and lock nut. at first i thought it was jerry-rigged, then saw that was the detail in the shop manual.

[monty]

Aaaah....2stroke

What are decent shape bikes like the nsr etc go for?

Reading this thread is making me drool a bit. My first "big" bike was a yamaha rd 350 (middle 70's model), followed by an rz 350.

The first one had a wickedly narrow powerband resulting in lots of unintentional wheelies in 1'st and 2'nd gear, the rz being more smooth (slightly anyway) in its power delivery...

Pure performance wise they couldn't keep up with the 3 and 4 pot 4 strokers (at double the displacement) of course, but fun wise, hitting that magic rpm where the thing rockets of, aah, oodles more fun then the big boys...

So, I'm kind of interested in a 150 or 250 2stroke fun machine...any tips?

Am pretty good mechanically, so no worries doing all the basic stuff/adjustments, the tinkering with it is part of the fun for me....

Cheers...

P.s. Recently had a zoom around on a dash 125, compared to my wave 125, makes you realize that cc for cc, 2 stroke has no competition!

Sent from my GT-I9001 using Thaivisa Connect App

[KRS1]

Aaaah....2stroke

What are decent shape bikes like the nsr etc go for?

Reading this thread is making me drool a bit. My first "big" bike was a yamaha rd 350 (middle 70's model), followed by an rz 350.

The first one had a wickedly narrow powerband resulting in lots of unintentional wheelies in 1'st and 2'nd gear, the rz being more smooth (slightly anyway) in its power delivery...

Pure performance wise they couldn't keep up with the 3 and 4 pot 4 strokers (at double the displacement) of course, but fun wise, hitting that magic rpm where the thing rockets of, aah, oodles more fun then the big boys...

So, I'm kind of interested in a 150 or 250 2stroke fun machine...any tips?

Am pretty good mechanically, so no worries doing all the basic stuff/adjustments, the tinkering with it is part of the fun for me....

Cheers...

P.s. Recently had a zoom around on a dash 125, compared to my wave 125, makes you realize that cc for cc, 2 stroke has no competition!

Sent from my GT-I9001 using Thaivisa Connect App

A decent well running example for 150cc's would be around 17k-25k baht, the lower end pricing from a private seller, the upper end from a dealer or farang. You can get them cheaper from a private Thai seller, but in the end it will end up costing as much as 17k-25k, if you are looking for good paint and reversion to stock appearance/performance (total engine rebuild not accounted for). If you can do the work yourself around 12k-14k after everything is said and done. Always make sure they have the original wheels and that the exhaust valves are operational.