Aprilia Riders

[mnphosis]

Originally posted by muser@Mar 15 2006, 11:46 AM

Of course I remember you, bro! William wasn't really doing any tuning, just doing basic maintenance and installing some jets I passed him, which I don't have any time to do myself. I'm very happy with the Maxima gear oil I'm trying for the first time though. I've yet to check out Maxima 2T though since I'm not on premix yet.

 

The 3-month-old Aprilia owner wasn't my friend,;I also only just met him there. I think his 2T settings something wrong lah. It seems 2T settings have some relation to how long the muffler packing in exhausts lasts, though I'm not sure what that relation is exactly.

 

I don't know if the Mito solenoid power valve motors operate in the same way as our Rotax Aprilia ones. You say that disconnecting the yellow wire opens your valve at all rpms? That doesn't sound like a great thing at all.

ah! so i now know who u guys r.

 

muser and jonathan:)

 

that joker u met there was me

 

toying ard with a 34mm carb and having the jetting set to 135/140.

 

Found 140 to be better after trying 135 and 140.

 

anyway, was great to have seen u guys but did not really indulge in a conversation as i was bogged down with some other things on my mind

[muser]

Originally posted by mnphosis@Mar 17 2006, 03:27 AM

ah! so i now know who u guys r.

 

muser and jonathan:)

 

that joker u met there was me

 

toying ard with a 34mm carb and having the jetting set to 135/140.

 

Found 140 to be better after trying 135 and 140.

 

anyway, was great to have seen u guys but did not really indulge in a conversation as i was bogged down with some other things on my mind

Good to see you online bro! With your setup, I'm not surprised you prefer 140 to 135 for your main jet size. It might be a good idea for you to try up to 150 even, just to see if there's an even bigger improvement If I had to guess, I would guess that 145 would be sui sui for your bike.

 

Don't worry about indulging in conversation lah - we were all there with time constraints, anxious to get our bikes done up properly, and it's always a good idea to discuss your needs thoroughly with William and Norman at Racewerkz to make sure they know what you want.

 

By the way, I suggest you also experiment with different 2T settings - for all you know, it might lengthen the life of your legal Arrow muffler packing.

[mnphosis]

Originally posted by muser@Mar 17 2006, 08:00 AM

Good to see you online bro! With your setup, I'm not surprised you prefer 140 to 135 for your main jet size. It might be a good idea for you to try up to 150 even, just to see if there's an even bigger improvement If I had to guess, I would guess that 145 would be sui sui for your bike.

 

Don't worry about indulging in conversation lah - we were all there with time constraints, anxious to get our bikes done up properly, and it's always a good idea to discuss your needs thoroughly with William and Norman at Racewerkz to make sure they know what you want.

 

By the way, I suggest you also experiment with different 2T settings - for all you know, it might lengthen the life of your legal Arrow muffler packing.

Thks for the tip! It was good to see you for real. have always wondered about the muser anyway.

 

I'd try the 2T thing as well since sometime back, after going 500km and seeing that my 2t level hardly moved, I got super worried and got william to richen my 2t flow.

 

I could have been wrong.

 

cheers

[muser]

Originally posted by mnphosis@Mar 17 2006, 09:42 AM

I'd try the 2T thing as well since sometime back, after going 500km and seeing that my 2t level hardly moved, I got super worried and got william to richen my 2t flow.

 

I could have been wrong.

Frankly, I still haven't found a 2T setting I'm completely happy with myself gonggong's experience has been that a lower 2T flow makes muffler packing last longer (both xxes123 and gonggong don't use much 2T for street riding). However, using more 2T gives your engine more protection.

 

Overseas 2-stroke mechanic A. Bell and oil company Maxima have both done studies showing how decreasing 2T flow even by a bit noticeably decreases engine protection. To complicate matters, your engine needs more 2T at high revs, but less 2T at lower revs, so a 2T setting that's sui sui for street will not provide enough protection for track use, whereas a track 2T setting will make your engine run really lousy on the street, not to mention leak plenty of 2T from your muffler tip. Most of us get around this by setting our 2T pump for street riding, and then on top of that adding 2T into our petrol tanks when we go track.

 

But you told me the other day that you only just changed your muffler packing and that it spoiled soooo fast So, it's tough to say what's best for your needs. Keep experimenting lah.

[xxes123]

Originally posted by mike1024@Mar 16 2006, 10:22 AM

if the exhaust valve is stuck open, i think that it would tend to lean out your cylinder in the lower rev range. this would contribute to your hearing the higher pitched engine note and more rapid pickup

the purpose of a valve in a Rotax engine enable the engine to have 2 distinct characteristic , responsive lower rev moving off and a powerful high rev..

 

like wise a bike wit a broken / struck valve wun feel much difference in the lower and mid range but high rev will be struck and the rush wun be there..

 

a bike w/o any valve => alway open position , will feel a very laggy lower rev but higher rev will be similar to wit a working valve..

 

its because wit the valve at close position at lower rev , it increases the compression and back pressure , at higher rev when the compression is very high when the valve open , exhuast gas flow out faster , hence the increase in power.

 

in simpler terms , the 2 stroke bikes work on the exhuast back pressure for the engine induction and the valve enable the back pressure to change hence the difference in power..

[muser]

Originally posted by xxes123@Mar 17 2006, 10:07 AM

in simpler terms , the 2 stroke bikes work on the exhuast back pressure for the engine induction and the valve enable the back pressure to change hence the difference in power..

More on this point

[jonathan543]

Originally posted by xxes123@Mar 17 2006, 10:07 AM

the purpose of a valve in a Rotax engine enable the engine to have 2 distinct characteristic , responsive lower rev moving off and a powerful high rev..

 

like wise a bike wit a broken / struck valve wun feel much difference in the lower and mid range but high rev will be struck and the rush wun be there..

 

a bike w/o any valve => alway open position , will feel a very laggy lower rev but higher rev will be similar to wit a working valve..

 

its because wit the valve at close position at lower rev , it increases the compression and back pressure , at higher rev when the compression is very high when the valve open , exhuast gas flow out faster , hence the increase in power.

 

in simpler terms , the 2 stroke bikes work on the exhuast back pressure for the engine induction and the valve enable the back pressure to change hence the difference in power..

wad i've experienced is the power surge came ard 5k rpm wit the valve staying opened all the way. when it came, the response is very sharp & shiok! however below 5k rpm, or moving off from standstill, it's very very sluggish & required quite abit of throttle to get a decent move off.

haha... read up once dat a 2t exhaust expansion chamber actually acts as a turbo charger for our bike! juz dat there's no mechanical or electronics involved. all operating on the energy of the pressure waves from combustion.

 

http://science.howstuffworks.com/framed.ht...stroketech.html

 

very interesting readup!

[jonathan543]

Originally posted by mnphosis@Mar 17 2006, 03:27 AM

ah! so i now know who u guys r.

 

muser and jonathan:)

 

that joker u met there was me

 

toying ard with a 34mm carb and having the jetting set to 135/140.

 

Found 140 to be better after trying 135 and 140.

 

anyway, was great to have seen u guys but did not really indulge in a conversation as i was bogged down with some other things on my mind

hi ya bro! hows ur bike liao?

i'm using 150 on my 32mm carb. runs a little rich so i'll be bringing my bike for a rejet soon.

any places can recommend? i wan the mech to actually ride & feel the bike instead of juz reving the bike & listening to the sound....

[mike1024]

best way, of course, is to do it yourself.

 

i doubt the mechs will be willing to try out your wide open throttle response, which is what is needed for proper selection of the main jet.

 

probably, on your bike, even 3/4 throttle on 5th gear is going to be illegal on expressways, let alone the back lanes near workshops.

[eyz]

maybe we have a jetting session?? lol

 

i need some jets to test out my bikes.. anyone got spares??

 

chris?? hahah

[muser]

Originally posted by jonathan543@Mar 17 2006, 11:45 AM

read up once dat a 2t exhaust expansion chamber actually acts as a turbo charger for our bike!

Yup, which is why it's quite crucial to get an exhaust system specifically made for your bike. If not, the powerband "hit" will hit too high or too low in the rev range, thereby not maximising power gains. This is a problem when boring or porting your block, which often ends up altering the powerband "hit" of your exhaust system. Most exhaust systems aren't tunable in the sense of being able to lengthen or shorten the various sections, and those that are aren't street legal.

 

You want the mech to tune, ride, and tune again till sui sui ah Not easy to find William and Norman do it, as well as a few others.

[jonathan543]

Originally posted by mike1024@Mar 16 2006, 11:20 AM

woah. that's cool. did it cost a lot of money? but shift light at 10.5? dunno what the mito engine redline is, but if it is anything like the RS125, 10.5 is cutting it pretty close, isn't it? what is the function of the shift light? to tell you when to shift, or is it a shift warning light - to tell you, when the LED comes on that it is pointless to hold the throttle open anymore?

 

in any case, nice but sorry, the precision is not enough for you to see the rpm variations or what the rpm actually is.

 

 

 

when the valve is stuck open, the cylinder leans out, lean mixtures have the habit of causing a rapid surge in rpm with very little torque. (someone correct me if i'm wrong) so for the same throttle position, you'd get a higher rpm.

 

 

 

what's going on? damage?

your not being able to rev up past 8k problem has been with you for some time, right? the other time, in response to some suggestions made here and on ARC, did you do anything to the bike carburettion?

 

did you try dropping a gear when you're stuck at 8k? does the rpm pick up? then did you try shifting to the 6th gear? does that work?

 

would you like to bring this thread to the ARC forum?

yup, it's quite a costy piece of gadget from uk... haha. mito redline is at 11k on the tachno. the shift light is to warn me i'm close to over reving liao, and i heard the peak power is somewhere juz be4 the engine is being over revved? anyway it's really cool when the shift light comes on. i had the leds to sweep from left to right with the raising of the rpm. when the shift light comes on, all the leds would light up & flash like running lights in random pattern! very cool & it's very noticable when trying out top at 2nd link at nite koz when all the leds are lit up, u can see them flashing from the corner of ur eye, thus keeping more concentration on the rd conditions. and i had the center led programmed at 7k rpm, to inform me when the power valve had opened. i've throttled to 7k rpm, as indicated on the rev meter & the center led lits up when the power valve started to move heheh...

 

so far i've oni changed to mikuni tm32 carb + k&N cone filter + main jet 150, moto tassirani v force3 reedcage & arrow exhaust. the engine is fully stock but is diff from a mito as planet uses a double ring piston & had a lower gearing at 14t front & 43t rear. nothing more was done to it ever since, though i experimented wit the mixture screw settings.

 

i dropped to 5th and my bike still accelerates but close to over revved liao. shift up to gear6 rpm still stuck after the rpm raises up. noticed on my digital speedo, whenever the speed exceeds 130km/h, the rpm & speed would then increase very very slowly, so far oni tried to a max of 145km/h nia. but my bike reaches 130km/h pretty easily & performance bwang after dat. or might be i'm using a cone filter instead of an airbox? any suggestions?

[muser]

Originally posted by eyz@Mar 17 2006, 12:08 PM

i need some jets to test out my bikes.. anyone got spares??

 

chris?? hahah

Hmm, if I remember right, I've got main jets 125, 130, 135, 140, 145, 155 (in my bike), 158 and 160. Also got idle emulsion tube 36 and 38. No spare idle jets though. Whatever I'm not using, you guys are welcome to borrow DIY is best, heheh, but you have to make sure you're doing it the right way and be careful. Jetting session ah? I'm probably free week after next.

[muser]

Originally posted by jonathan543@Mar 17 2006, 12:15 PM

planet uses a double ring piston

 

...

 

but my bike reaches 130km/h pretty easily & performance bwang after dat. or might be i'm using a cone filter instead of an airbox? any suggestions?

You mean all Mitos use single piston rings?!

 

I'd suggest you put back the stock airbox without filter, then try. You can also try a smaller main jet (148, 145) if you can be confident it won't be too lean.

[jonathan543]

mike bro, u mean plug chop? can do at 40 tiang at lck ma... heheh... i readup too dat no need to go full throttle at too high a gear. full throttle after proper warming up on gear 4 is sufficient, though i forgotten how long is the duration liao...

wow chris bro, seemed we cant have best of stuff huh? to have the best performance, every single component muz be designed & built to be working together...

 

other than main jet, wad other jets can be changed? koz i heard most of the newer carbs are having fewer jets or jets dat are built in & cant be changed.

[jonathan543]

Originally posted by muser@Mar 17 2006, 12:23 PM

You mean all Mitos use single piston rings?!

 

I'd suggest you put back the stock airbox without filter, then try. You can also try a smaller main jet (148, 145) if you can be confident it won't be too lean.

dats wad i gathered from the planet's thread. doesnt aprilia uses single ring piston too? i might take to vector one to rejet, koz he claims he'll ride & test the bike till the jettings are rite, though i din noe how he'll manage to do a plug chop... for a fee of $80.

william dun have so many jet sizes. infact he fitted a too big sized main jet in my old 28mm carb the 1st time i sent my bike for jetting. made my bike choke & fuel was overflowing out of the carb. so bad dat water condenses on the carb... after i show him the problem & was changed to a bigger carb, the main jet was still too big in my new 32mm carb. so he fitted a 160 but i still find the engine choked at time. so gone down to 150 since he dun have a 155. roughly wads the best jet size for a 32mm carb? william oso advised me not to go for a 35mm carb as i have a stock engine...

[mike1024]

Originally posted by muser@Mar 17 2006, 12:15 PM

Hmm, if I remember right, I've got main jets 125, 130, 135, 140, 145, 155 (in my bike), 158 and 160. Also got idle emulsion tube 36 and 38. No spare idle jets though. Whatever I'm not using, you guys are welcome to borrow DIY is best, heheh, but you have to make sure you're doing it the right way and be careful. Jetting session ah? I'm probably free week after next.

does the planet 32mm (mikuni?), dell'orto 28mm and 34mm carbs use the same main/idle jets?

 

i have 132, 135, 140 (installed), 142, 145 main jets

 

not as many.

 

plug chop at LCK? perfect place, but let's not talk too much about it here.

 

jon i sent you email.

[xxes123]

Originally posted by muser@Mar 17 2006, 12:15 PM

Hmm, if I remember right, I've got main jets 125, 130, 135, 140, 145, 155 (in my bike), 158 and 160. Also got idle emulsion tube 36 and 38. No spare idle jets though. Whatever I'm not using, you guys are welcome to borrow DIY is best, heheh, but you have to make sure you're doing it the right way and be careful. Jetting session ah? I'm probably free week after next.

christ : wan try mainjets 170, 172 ,175- 190... idle jets 50-62..

 

i most prob going for 175 and above....

 

mainjet 158 , idle 45 petrol not enough... me bike big drinker... monster jets best...

 

anyway word of advise .. dun WOT , 140-160+ in theory is all tooooooo small liao based on race setup using 34mm carb, esp using knn open pod cone filter...

[alanhim]

Guys we are planning to go Sepang in KL on the 1st or 2nd April or both day for track session. As Nothing is confirm yet I just need a show of hand how many people are interested of going so that I can plan better. Pls add your name in first if you are interested. That's no obligation.

 

1st or 2nd April (Not confirm yet)

 

Track sessions is at RM75 per session (250cc & below)

RM100 for 250cc and above.

 

Detail as follows:

 

Saturday 1 Apr 2006 - 2 PM to 6 PM.

Sunday 2 Apr 2006 - 9 AM to Noon.

 

1) Alan

2) Myapriliabigbore

3) spiderman(pending)

4)

5)

[mike1024]

stock aprilias use double ring pistons, because it is more reliable in the long run. Although i read somewhere that single ring pistons are preferable on the (race)track becuase they wear out slightly faster, and hence the run in period of rebuilt race engines are much shorter.

 

We're talking in the category of performance tuning where rebuilds are done every other race (???), but if you are not going to do an overhaul every 5000km, for example, best not to use single ring pistons if they are not the stock specification.

[mike1024]

Originally posted by xxes123@Mar 17 2006, 12:38 PM

christ : wan try mainjets 170, 172 ,175- 190... idle jets 50-62..

 

i most prob going for 175 and above....

 

mainjet 158 , idle 45 petrol not enough... me bike big drinker... monster jets best...

 

anyway word of advise .. dun WOT , 140-160+ in theory is all tooooooo small liao based on race setup using 34mm carb, esp using knn open pod cone filter...

err, can i say that you very hardcore?

 

me, still on stock 28mm carb. so, i'm still quite happy with 140.

 

your airflow using the pod filter must be huge - you tried 170+ and it still does not bog?

 

ya, agree no need for truly WOT, about 70 to almost 90% should be enough to select main jet.

[jonathan543]

Originally posted by mike1024@Mar 17 2006, 12:37 PM

does the planet 32mm (mikuni?), dell'orto 28mm and 34mm carbs use the same main/idle jets?

 

i have 132, 135, 140 (installed), 142, 145 main jets

 

not as many.

 

plug chop at LCK? perfect place, but let's not talk too much about it here.

 

jon i sent you email.

from wad i gathered from william, keihin & mikuni jet sizes are diff even though they're having same jet sizes?

single ring piston are supposed to be able to rev higher is it? but double rings had a betta seal, so having more torque at lower rpms but not able to rev up dat high as a single ring? alot of theories heard but dunno most of them true or not... heheh...

 

planet stock came wit dell-orto 28mm, same wit mitos & aprilias. i want to change to a 35mm keihin but was adviced against it. so got a mikuni 32mm instead since keihin doesn't make 32mm one liao.

[mike1024]

no, what i meant was that i wanted to know if the jets were interchangeable between dell'orto 28 and 34, and mikuni 32

 

won't speculate on stuff i don't know about either. (the single versus double rings), though i've read here that double rings offer better sealing, while more rings imply more friction.

 

whether or not the low rev/high rev performance is affected by single/double rings, i am not sure.

 

Can someone verify, with source?

 

these are the kinds of discussions we should be having on ARC leh...

[muser]

Originally posted by jonathan543+-->

QUOTE (jonathan543)

other than main jet, wad other jets can be changed? koz i heard most of the newer carbs are having fewer jets or jets dat are built in & cant be changed.[/b] Mikunis in general have fewer jets that can be changed compared to Keihin and Dell'Orto, as far as I know. Not sure about your particular Mikuni though.   Originally posted by jonathan543+--> QUOTE (jonathan543) william oso advised me not to go for a 35mm carb as i have a stock engine[/b] Strange advice. I wonder what his reasoning is.

[AH_PEK_LAH]

Originally posted by alanhim@Mar 17 2006, 12:41 PM

Guys we are planning to go Sepang in KL on the 1st or 2nd April or both day for track session. As Nothing is confirm yet I just need a show of hand how many people are interested of going so that I can plan better. Pls add your name in first if you are interested. That's no obligation.

 

1st or 2nd April (Not confirm yet)

 

Track sessions is at RM75 per session (250cc & below)

RM100 for 250cc and above.

 

Detail as follows:

 

Saturday 1 Apr 2006 - 2 PM to 6 PM.

Sunday 2 Apr 2006 - 9 AM to Noon.

 

1) Alan

2) Myapriliabigbore

3) spiderman(pending)

4)

5)

alan cooking soup today ???