at long last... naka-basa rin ng updates. tagal ko kasi nawalan ng access dito sa upis. back read ng malupit.
dinala ko sa motortrade si thunder kahapon for check up. sabi dun, they refrain from opening carbs until odo reading reaches 4000KM. ayaw ko naman ipagalaw sa iba mechanic dahil baka mawala warranty. so for now, i'll just have to go easy on the gas.
share ko na rin first bonding moment ko with the thunder. inakyat ko sa teresa rizal yung thunder to see how it performs. happy to say that the ride is very comfortable. handles the curbs well even with stock tires. medyo malambot ang front suspension, halos tukod pag late or hard breaking, but this setting is just right since the bike will be used mostly for city driving. i prefer kung mas stable ang manibela, and a steering damper would really help, but with enough rider input the bike behaved well enough and was very reasssuring with the exception of some bulaga moments (due to human error and not the bikes fault).
what i like most about the bike is this:
pag naka-park sya at tinititigan ko, parang gusto ko talaga ibenta........ pero pag sinakyan ko at umaandar na, parang ayaw ko naman bumaba.
looking forward to joining you guys. open minded naman ako, hehehe. and the bike does a very good job of convincing me. pakitang gilas agad. it just feels so right. power delivery is above par for a 125cc, but it's not powerful enough to scare the bejeezus out of a sissy like me. swak na swak lang ang perfromance. mas comfortable ako isagad ang thunder kesa sa wave dahil hindi nakakaawa ang engine vibration and it's much more stable. for now, that's enough reason (aside from practicality) to stop me from obsessing about other standard bike models.
i can only afford to own one bike at a time, so it's now a matter of whichever bike gets sold first. so far, mas marami inquiry about wave, but they are low ballers. i hope somebody offers a reasonable price. para may budget na agad pang set-up kay thunder.
I have ridden mine for about 6 mos and odo is running at 5k+ already. Found few problems like there were instances that when I push the throttle, it got stock up a little that I have to kill the engine and re throttle during engine is off to make the throttling normal. This instance happened in the morning. Happened around 2-3 times since then, and now its been a long time since the incident. Pero one thing talaga irritates me with Thunder, its the persistence of the quack sounds of the swing arm. I already had this greased twice, but no luck. When they greased this. the quack disappeared for a day, then next day, nandyan na naman sya. The mechanics even admitted that this has been the main issues of Thunder that they are servicing. Oh well. Buti na lang mine still lives up my expectation, that is, to save me bucks from a good fuel efficiency. So far getting around 44-47 Km/L (realistically no BS) which I think is good enough. Ako din nag isip na ibenta to, specially when the CBR 150fi comes out, pero napagmuni muni ko, all I need is a ride for work na matipid, so I think sa susunod na lang pag marami nang pera. Bottom line, im still happy with mine.
I've had my bike for more than 6 months now.
It is at 10055 Km odo readiing - I'd say the more the bike matures it gets even better.
Meaning I have gotten to know how the bike handles, feels and responds. Me had that throttle response but after my PMS service at 4000Km all went WELL infact I can list some that are no longer present
1. Vibration at 5k-6k Range on 2nd and 3rd gear
2. Throttle response na parang nahagok o nasamid when pushing it to 4th gear then goes to engine break
3. Have not been using choke on cold startup until now.
4. squicky sound on Swing arm pivot pin
Just like you guys. When I get down from the saddle I always find myself staring at the bike. Then wanting to ride it again. Only reason is hindi ko alam kung saan ako pupunta. Basta gusto ko mag ride!
Suzuki Invasion Run Finisher> North Loop; South Loop
1st tune up ng thunder ko 3600 pa lang ang takbo pina sched ko na sa planta nakita ko si kuya ricky pina check nya yung thunder nya..nag pa sched ako ng check up kasi akyat kami ng baguio.. napansin ko lang umingay yung makina.. ito nga pala ginawa sa thunder ko..
1. clean carb
2. nilinisan yung PAIR
3. valve clearance
4. linis ng sparkplug
5. tapos align yung timing chain
napansin ko lang umingay yung makina ko at masyadong mataas yung idle ko pag binababa ko namamatay naman. hindi ko alam kung sakit na talaga ng suzuki yung maingay yung makina ng mga motor nila . all in all hindi naman ako iniwan ng thunder ko nung paakyat at pa uwi na kami ng baguio.. from manila to baguio nga pala ang tinakbo namin..
I find that weird.
Normally pag napa tune up kona from plant is tumatahimik yung engine ko. Mas maingay mas kailangan ko na ipatune up. You can bring this up to them so they can look it up.
Yung idle ko naman sinunod lang nila sa 1.2 -1.4 ba yun? so far ok naman and hindi na nga ako gumagamit ng choke sa cold start. Basta maganda warm up panalo ang engine response.
Walang ka effort effort
Suzuki Invasion Run Finisher> North Loop; South Loop
good day thunder peeps.
kindly help me naman. baka may kilala kayo gusto ng sariwang thunder. 62K na lang cash. or 30K down, 6K monthly for six months(subject to CI). almost like zero% installment. even though i've grown to like my thunder, i just recieved an offer i can't resist.
hindi ko nga malaman eh ang laki ng pinag bago ng motor nung pina tune up ko, dati kasi kapag 1 ang idle ko hindi nadedeads ngayon kailangan 1.2 or 1.4 kapag sobra na ang init papalo na sya ng mga 1.5. kanina nilinisan ko yung air filter at spark plug nung pag ka start ko ok naman na 1.1 ang idle ko hindi naman namamatay. ang pinag tataka ko lang parang ang ingay ng mga valves rinig ko yung lagitik.
anyone of you guys na me alam kung sino marunong gumawa ng megaphone type pipe for the thunder? gagawin ko na kaseng cafe racer project yung akin
Baka hindi kasama sa valvle clearance adjustment yung PMS mo pero like I have said you can call them up at sabhin mo me issue pa din para naman maayos.
BTW kala ko benta mo Bar ends mo? pm me for contact info.
Suzuki Invasion Run Finisher> North Loop; South Loop
"A happy wife is a happy life" - Makoy
this is a good read on our CV carbs,
CV (Costant Velocity) CARBS
In respect to these carbs, I'll be talking about the intake side, and the exit side. Air comes into the intake side and exits out of the engine side as fuel mixture.
The CV Carb has a more complex air control system than the two carbs described above:
---The butterfly valve is back, and sits toward the engine side of the carb. It is opened and closed by means of the throttle and throttle cable and controls the amount of air that can flow through the carb.
---But the slide is retained. It sits in the middle of the carb on the intake side, before the butterfly. But instead of being pulled up and down by the throttle cable as in the slide carb, it now has no direct connection to the throttle cable at all. It is now attached to a rubber diaphragm and is raised and lowered by vacuum (depression) introduced on the top side of this diaphragm through holes drilled up through the slide. The slides in Hitachis are round, and in Mikunis they are flat.
Now we'll try to figure out how CV carbs work.
When the butterfly valve is closed, very little air is moving in the carb bore. (The engine is getting some air and fuel through the pilot circuit, which we'll describe later.) With little to no air flowing, the air in the carb bore and the air in the closed chamber above the diaphragm are at close to the atmospheric pressure of the outside air.
Open the butterfly, and several things happen.
1. Air now speeds through and venturi effect (depression) at the point of the slide (variable venturi) is created.
2. The depression at the venturi is transmitted up through the holes in the slide to the closed chamber above the diaphragm. This lowers the density of the air in that chamber.
3. The open air below the diaphragm now wants to rush into that chamber to equalize the pressure, but it can't because there is no passage.
4. So it does the next best thing and tries to push its way in through the underside of the diaphragm.
5. The diaphragm can't let the air in, but it is flexible so gives way it is pushed up by the outside air pressure.
6. As it goes up, it pulls the slide with it, and the slide pulls the tapered fuel needle up in the fuel hole.
7. More air flows, more fuel is pushed into the air stream, and the engine accelerates or runs at higher revs.
But how does this improve things over the simpler slide carb?
When the throttle is cranked on the slide carb, the slide is pulled up immediately by the throttle cable, expanding the variable venturi suddenly, and causing the lean stumble described above.
When the CV butterfly is opened, the slide does not immediately jump up to a much more open position. It raises gradually as the increasing engine revs provide the needed depression (at the venturi), which is then transmitted to the chamber above the diaphragm. As the slide rises, the increasing depression also encourages more fuel to enter the carb bore and combine with the greater air supply now available. And the higher the slide goes, the more fuel the tapered needle permits to flow. In other words the genius of the CV carb is that the fuel from fuel hole can now "keep up" with the increasing air available--maintaining the mixture at proper ratios during the accelereation process.
In summary, the CV carb provides quick enough acceleration (no lean stumbles to slow things down) which is also smooth. And overall we get a "kinder, gentler" carb which gives us less twitchy responses as we make small throttle adjustments.
Now we'll get into:
Carbs are such that they cannot meet all the different running situations with one single system. Starting, idling, acceleration, deceleration, and steady running all impose different fuel requirements on carbs. Carbs also have to handle different engine speeds, different loads, different engine temperatures and other variables. So we find that CV carbs need three distinct "circuits" or fuel delivery systems to meet these different needs. The three circuits are:
The starting circuit, the pilot circuit, and (what I call) the run circuit.
The starting circuit (often called the choke circuit--but it doesn't really "choke" anything) provides a special fuel supply needed to start the engine, when the engine is cold.
Why does the engine need a lot of fuel to fire when it is cold? For a fuel mixture to ignite, it needs to be made up of very tiny (atomized) particles of fuel suspended in the air. Cold fuel tends to stay in big drops which don't ignite easily. Also these big drops tend to cling to intake walls. So in a cold engine, a lot of the fuel doesn't atomize correctly and is just wasted. Therefore you need more fuel to start with to make up for these losses, and assure that enough of it is atomized to give you a mixture which will ignite properly. As the engine warms up, atomization becomes much better and more complete, so less fuel is needed to create the proper air/fuel ratio, and the start lever can be let off.
The starting circuit is really a separate system in the carb. It takes its air from a port in the bore which is located in the main air path before the slide and the butterfly. It gets its fuel from a separate tube running into the float bowl. When the start lever is pulled at the handlebar, a plunger is lifted which opens the air and fuel passages. The engine is then cranked, and since these passages are small, you get you get the needed air speed going through them with enough venturi effect to draw fuel from the bowl into the air stream. This mixture exits from a port on the engine side of (after) the butterfly and goes on into the cylinder.
This circuit, if working properly, is designed to provide the proper mixture all by itself to start the bike. Hence the admonition; "start your bike with the throttle closed." (Note also that closed throttle starting is also easier on the starter, since the piston is not pulling in a full gulp of air. Compression is about half of normal and the starter doesn't have to work as hard to crank the engine.) As the bike warms up, the plunger has a half open position which cuts the fuel back but leaves the air open, leaning out the mixture. On full warm up the plunger is closed and cuts off both passages. Note that different bikes have different starting habits, and a quick blip after the engine catches helps with some of them. Outside temperature can also affect how you use the choke. (O.K. I'm calling it the choke) More choke on cold days, less on hot days.
This is sometimes called the "idle circuit" but it does a lot more than control idle. And it is perhaps the most misunderstood of the three circuits. The role of the pilot circuit is basically to run the engine when the throttle is closed, as when the engine is idling or the throttle is closed on deceleration. But this circuit is also the main source of fuel at very small throttle openings. As the throttle is opened past 1/4, the importance of this circuit diminishes, as the main fuel supply is now provided through the main "fuel hole" and controlled by the needle/needle jet and ultimately the main jet. But the pilot circuit does remain active and makes a (progressivley smaller) contribution all the way to WOT.
The typical set up is this: The pilot circuit get its fuel from the float bowl through the pilot jet. The circuit also has a pilot air jet, but the purpose here is not to provide all the needed air (as in the starting circuit), but to provide air to premix with and partially aerate the fuel before the mixture enters bore and completes the atomization process with air traveling through the bore. Such little air passages are sometimes called "air bleed" circuits.
This circuit typically has two outlets. One is called the "pilot outlet" and is located on the engine side of the butterfly valve. This outlet supplies the fuel mixture to support idling and deceleration (that is, off-throttle running). It has an adjustment screw which controls the amount of fuel mixture entering the bore under off-throttle conditions. This screw is sometimes mistaken for an "air screw" but it is not. Turning in (right) reduces the amount of fuel mixture, and turning out (left) increases it. In for lean, out for rich.
The other outlet is call the "bypass outlet" and is located right at the point in the bore where the bottom of the butterfly comes to rest when closed. Typically, the butterfly is set a tad open to permit just a slight amount of air to pass by at the bottom to support idle and decel, and most of the fuel for these functions is supplied through the pilot outlet. But as the butterfly is opened, more air flows past it, and the venturi effect starts to work on the bypass Additional fuel is now drawn out of the bypass to support low speed running and cruising at small throttle openings. (Note that if the butterful valve is adjusted to 'fully closed' the engine will probably not start or idle. It needs to be open a tad. As mentioned above, these outlets continue "giving" throughout the rev range, but their contribution to the overall mixture dimishes as the slide rises.)
An addition to this circuit is found on later Hitachi and all Mikuni carbs. This is the "coasting enricher". A typical problem in earlier carbs was the fact that when you chopped the throttle (closed the butterfly) on deceleration, there would not enough fuel in the mixture at the (at that moment) high revs to allow the engine to fire consistently. You would then get a "lean misfire". That is, the engine would fail to fire, and the unburned mixture (lean though it was) would enter the exhaust header. Then when the engine next fired, you'd get a backfire. (So backfiring on decel is typically a lean condition, and not "loading up" as some people think.) The solution they came up with was to reduce the amount of air in the "airbleed" circuit by about half, meaning the fuel content hitting the bore from the pilot oulet was much higher than the normal idle fuel mixture you get on closed throttle. Once the revs came down, the full air bleed would be restored for proper idling. The "coaster enricher" is activated by the strong vacuum created in the carburetor holder (intake stub) byhigh revs when the butterfyl is closed on decel.
On Hitachis some external piping was added to service these diaphragm driven valves. On Mikunis the needed passages were drilled into the carb bodies.
Of special note: we now understand that those adjustment screws only affect the pilot circuit, and mainly the mixture on idle and decel.
THE RUN CIRCUIT
This circuit takes its "airbleed air" from the main air jet, and its fuel from the float bowl. The fuel travels up through the main jet, and is pre-mixed with air from the main air jet in the needle jet (called by Yamaha in the Hitachi years the "main nozzle"). This needle jet is a long jet with holes in the side to permit the air to enter and be mixed with the fuel--before this mixture plumes out into the main bore to be further atomized as it heads to the cylinder. The tapered metering needle rides up and down in the needle jet and meters out more fuel the higher it goes. At wide open throttle (WOT) the slide and needle are fully raised and the needle is effectively "out of the way" in the needle jet, allowing maximum fuel to flow into the carb bore, regulated only by the size of the main jet.
When does the needle taper cut in? If you put a digital caliper on a Hitachi needle, you will find that it does not taper for the first 3-4 millimeters residing down in the needle jet. So presumably until the slide raises more than 3-4mm, we are still in "pilot circuit county", since with no taper the needle jet is pretty well filled with the needle and little additional fuel will be pushed out that hole. Once the taper cuts in additional fuel starts to flow out and this progressive metering continues until the much steeper taper of the needle drops it out of the game as WOT is approached, and the main jet becomes the only restirction..
Note that jet changes typically involve the main jet, and to a lesser extent the pilot jet. In these carbs we never seem to get into the air or needle jets.
An interesting thing to do is to make some marks on your throttle showing its position at 1/4, 1/2, 3/4 of rotation and WOT. You'll be surprised to see how little the butterfly is actually open at steady cruising speeds. You'll see some serious throttle rotation on brisk acceleration, but just try to maintain a steady speed at high throttle openings on the freeway. This will get you too much speed or too many speeding tickets, whichever comes first.
So those are the three circuits. Half the trick is diagnosing carbs is to figure out fuel, air and outlet paths for the various circuits. Note there is a degree of independence between the pilot circuit, the needle/jet, and the main jet. For example, we are told that the engine will start and idle on the pilot circuit with no needle or main jet in the carb at all (I've never tried it). Also, the engine could, I suppose, run up to some point (mixture being controlled by the metering needle) with no main jet in place. (Not to be tried with Hitachis, since the main jet screws into the needle jet and holds it in place.)
As we have now seen, the CV carb needs the presence of outside air (at atmospheric pressure) inside the carb for several reasons:
--Outside air is needed under the diaphragm to push it up.
--Outside air is needed above the fuel in the float bowl to push down on the fuel and force it up past the various jets and into the starting, pilot and run circuits.
--And outside air is needed to service one or more of the air jets that reside inside the carb body..
How does this outside air get in? It gets in through the breather pipe which sits toward the top of the carb just under the diaphragm. Air jet(s) also reside in this space and have access to it. And drillings in the carb body allow the outside air to go down and enter the space above the fuel in the float bowl.
A breather tube typically attaches to the breather pipe and extends to some point (e.g., behind a side cover, or inside the aircleaner pod) where the air is relatively calm. Why? We don't want wind to be changing the airpressure at the end of this pipe, because this will disturb the operation of the air jets, the diaphragm, and the fuel delivery. These functions need consistant outside air pressure to work properly against the various levels of depression created in the bore, above the diaphragm, etc., as the carb goes about its work.
Hopefully we now have a general idea about what is going on inside our carbs.
"A happy wife is a happy life" - Makoy
mga bro newbie lang ako sa motor na single thunder binili ko mga 1 week na sakin pero may mga sidecar ako. tanong ko lang baka may alam kayo na carrier / bracket na fit sa thunder para malagyan ng luggage box or givi box? san ba pwede makabili or makapagpagawa ng bracket? inikot ko buong 10th avenue pero wala lahat silang bracket para sa thunder. patulong mga bro. thanks!
OT: mga troopers, may suzuki invasion sa SM taytay. feb 17, 18 and 19. free change oil and check up for all suzuki bikes. then motokhana sa 20th. baka gusto nyo pumasyal.
yeah, both my bikes are for sale. but not because i don't like them anymore. ganda lang talaga deal na offer sakin. i'm riding the thunder now habang wala pa buyer. pag nag-expire yung offer sakin, thunder for long run na din siguro. kaya nga i'm looking around for thunder mods na, hehehe. sayang, di ko ma-access karamihan sa mga troops pages, hirap tuloy kumuha ng ideas. layo din ng troops tambay kaya di ako makapasyal.
as for the invasion, baka hindi na advertise masyado, kasi taytay pa lang super dami na suzuki riders. but i'll be there. pa-check ko valve clearance and carb ng thunder. lumalagitik eh, tsaka sinisinok pag nabibigla throttle. ayaw galawin sa motortrade dahil masyado pa daw bago.