Post by Lucass2T on May 1, 2014 7:47:34 GMT -5
Hi guys
My name is Lucas and i'm from Holland.
In the summer of '12 i got two Yamaha axis from my neighbor for free! One was registred and the other for parts. My neighbor gave them to me becouse his daily driver died one day and he didn't want to get it repaired again becouse it would get too expensive. ''it's an old scooter after all'' he used as argument. Lucky for me i used to work as a moped mechanic so fixing it wasn't going to be a problem.
Anyway, after a quick checkup i found the vacuum fuel supply wasn't working. I replaced it and the axis ran like it hadn't been running for al long time! So, easy fix
This is what they looked like the day i got them. (My streelegal and registred CR500 in the back)
This one was the formerly daily driver. All dusty becouse it hadn't been used for ages
After a few weeks i bought a Yasuni R and that gave me a topspeed of about 75kph/47mph. Still had a decent mileage, no excessive noise and could stille use the oilpump. All pretty functional but on the bigger roads i JUST couldn't keep up with traffic. Speedlimit (outside of towns and cities) is 80kph/50mph so i came short of only a few mph, so i kept on holding up traffic. Pretty annoying having cars and trucks breathing in your neck all the time. So time for some upgrades!
I really liked the functionality of this little scooter, electric starter, auto choke, low noise, lowdown torque, good mileage etc. etc...So i decided i wanted to keep that. Keeping that in mind i put together a nice dailydriver worthy setup:
Metrakit SP3 70cc
Metrakit SP exhaust
20.5mm Dellorto PHVB (auto choke)
Twin-air 70mm airfilter
Malossi VL14 reed
Doppler crank
Polini speedcontrol variator
Twins Racing 122mm overrange rear pulley (straight splines)
DMP deltaclutch (malossi deltaclutch rip-off)
DMP bell
Malossi 17/40 gearing
Aim: about 10hp and a nice flat curve + be able to use all the funtions a stock scooter has.
I also bought some nice Dunlop TT92 tires to handle the high speeds. Afterwards i noticed the original tyres can handle the same speeds as the Dunlops....But the dunlops were pretty cheap and look much cooler so no problem.
So i bought this cylinderkit on discount for €124, thats about $172.
It's a copy of the Athena racing and Stage 6 racing. Flat piston, double exhaust port and 5 transfers.
New bearings and seals all around, crank, transmission, front wheel. To be sure it's all perfect.
Did some small work on the cases, just to match the cylinder.
Right, so in august '13 i got it running, one week before i left to Budapest (Hungary) to study there for 6 months. When i got back in Februari '14 it was too cold outside to go out for testing and tuning so i had to wait for better weather
Anyway, at the moment it's getting summer and i'm in the middle of tuning the engine. When driven about 1000km/620 miles already tore down the engine becouse of crank vibrations. Solved that and it's running quite strong now. But in the process of tuning the engine i found a really annoying side effect, intake NOISE! I'm running an open airfilter with a horn like mount, so when i crack the throttle the whole neighborhood hears me coming (and also the police).
You can see the blue cylindrical foam filter with 70mm inlet. I used two silicon reducer elbows i bought off ebay. reducing from 70mm to 55mm and further reducing from 55 to 40mm (40mm is carburettor inlet size). This reducer setup acts like a megaphone so i needed to come up with a solution.
So i made an intake muffler from a fishfood jar
. It has 3 air chambers and it works PERFECTLY! It's as quiet as a stock airbox! I can post the details of the muffler if ppl like?
You can see the custom airbox/muffler under the footrest
With this airbox i didn't need to change the jets so it has NO loss of flow compared to the open airfilter. But the loud intake noise is completly gone! So a win-win situation.
I did a few top speed runs, and this came out. I used 2 different applications but time and time again they showed the same numbers.
112 kph or 70 mph. And it's not yet running out of gears, but the engine hasn't enough power to take it to higher speeds. So it's not going into over-revs and thats a good thing i guess. I can keep the engine right in its powerband all the way to it's topspeed.
Right now i did 1100kms with it, at 1500km im gonna remove the cylinder for inspection and then i will take care of this:
I don't think i will notice the difference when the flange and exhaustport are flush, but it's more for my own peace of mind.
My name is Lucas and i'm from Holland.
In the summer of '12 i got two Yamaha axis from my neighbor for free! One was registred and the other for parts. My neighbor gave them to me becouse his daily driver died one day and he didn't want to get it repaired again becouse it would get too expensive. ''it's an old scooter after all'' he used as argument. Lucky for me i used to work as a moped mechanic so fixing it wasn't going to be a problem.
Anyway, after a quick checkup i found the vacuum fuel supply wasn't working. I replaced it and the axis ran like it hadn't been running for al long time! So, easy fix
This is what they looked like the day i got them. (My streelegal and registred CR500 in the back)
This one was the formerly daily driver. All dusty becouse it hadn't been used for ages
After a few weeks i bought a Yasuni R and that gave me a topspeed of about 75kph/47mph. Still had a decent mileage, no excessive noise and could stille use the oilpump. All pretty functional but on the bigger roads i JUST couldn't keep up with traffic. Speedlimit (outside of towns and cities) is 80kph/50mph so i came short of only a few mph, so i kept on holding up traffic. Pretty annoying having cars and trucks breathing in your neck all the time. So time for some upgrades!
I really liked the functionality of this little scooter, electric starter, auto choke, low noise, lowdown torque, good mileage etc. etc...So i decided i wanted to keep that. Keeping that in mind i put together a nice dailydriver worthy setup:
Metrakit SP3 70cc
Metrakit SP exhaust
20.5mm Dellorto PHVB (auto choke)
Twin-air 70mm airfilter
Malossi VL14 reed
Doppler crank
Polini speedcontrol variator
Twins Racing 122mm overrange rear pulley (straight splines)
DMP deltaclutch (malossi deltaclutch rip-off)
DMP bell
Malossi 17/40 gearing
Aim: about 10hp and a nice flat curve + be able to use all the funtions a stock scooter has.
I also bought some nice Dunlop TT92 tires to handle the high speeds. Afterwards i noticed the original tyres can handle the same speeds as the Dunlops....But the dunlops were pretty cheap and look much cooler so no problem.
So i bought this cylinderkit on discount for €124, thats about $172.
It's a copy of the Athena racing and Stage 6 racing. Flat piston, double exhaust port and 5 transfers.
New bearings and seals all around, crank, transmission, front wheel. To be sure it's all perfect.
Did some small work on the cases, just to match the cylinder.
Right, so in august '13 i got it running, one week before i left to Budapest (Hungary) to study there for 6 months. When i got back in Februari '14 it was too cold outside to go out for testing and tuning so i had to wait for better weather
Anyway, at the moment it's getting summer and i'm in the middle of tuning the engine. When driven about 1000km/620 miles already tore down the engine becouse of crank vibrations. Solved that and it's running quite strong now. But in the process of tuning the engine i found a really annoying side effect, intake NOISE! I'm running an open airfilter with a horn like mount, so when i crack the throttle the whole neighborhood hears me coming (and also the police).
You can see the blue cylindrical foam filter with 70mm inlet. I used two silicon reducer elbows i bought off ebay. reducing from 70mm to 55mm and further reducing from 55 to 40mm (40mm is carburettor inlet size). This reducer setup acts like a megaphone so i needed to come up with a solution.
So i made an intake muffler from a fishfood jar
. It has 3 air chambers and it works PERFECTLY! It's as quiet as a stock airbox! I can post the details of the muffler if ppl like?You can see the custom airbox/muffler under the footrest
With this airbox i didn't need to change the jets so it has NO loss of flow compared to the open airfilter. But the loud intake noise is completly gone! So a win-win situation.
I did a few top speed runs, and this came out. I used 2 different applications but time and time again they showed the same numbers.
112 kph or 70 mph. And it's not yet running out of gears, but the engine hasn't enough power to take it to higher speeds. So it's not going into over-revs and thats a good thing i guess. I can keep the engine right in its powerband all the way to it's topspeed.
Right now i did 1100kms with it, at 1500km im gonna remove the cylinder for inspection and then i will take care of this:
I don't think i will notice the difference when the flange and exhaustport are flush, but it's more for my own peace of mind.
??
. 
