bb 70cc kit

[dwint51]

I showed my scoot to a mechanic and he said for 250 he would put the kit in for me.he said the pipe I have has no restrictions and he's put a lot of these in.is it worth it for the extra 20 cc

[dwint51]

I showed my scoot to a mechanic and he said for 250 he would put the kit in for me.he said the pipe I have has no restrictions and he's put a lot of these in.is it worth it for the extra 20 cc
its a minerelli 2t

[blueboy5000]

Well a 63cc BBK won't make you any FASTER, it will make you ACCELERATE better, but will NOT INCREASE top speed.

[teddy554]

yes

[skuttadawg]

Yes a BBK on a 4T will not yield a faster top end as I had a TaoTao ATMa and went from a " secret 63 " to a 50mm or 82cc BBK . Had better take off , midrange and uphill but the same top end .

Now on my 2T which has a Minareli it would hit 45+ with only going from a 68 main jet to a 75 . It would max out at 8k RPMs and fizzle if it went about that and if I hit 9k downhill it would really fizzle and want to stall . Replaced the CDI with a blue racing one had the exact same top end and 8k limitation .

I put on a 47mm or 70cc BBK and noticed the exhaust port on the 40mm or 50cc was D shaped instead of a full circle like the 70cc has . I also put on a PM Racing pipe that had no baffle and a Uni airfilter . Takeoff was less since it did not have the back pressure like the stock pipe had but wow midrange and top end were a lot faster and not it can hit 10,500 RPMs instead of 8k . My Jonway Magnum has a handsome boy body like the Peace VIPs and others have so I could remove the seat bucket and body under the seat as a single piece instead of panels like some other body styles . I removed the fan shrouds and tada engine access without having to drop the whole assembly out of the frame . The head is held on by 4 nuts on studs . Remove the nuts and the head slides right off . The cylinder came off with ease to . I used compression ring pliers from Oreillys Autoparts since long ago I did break some rings when I tried by hand . Use snag ring pliers for the wristpin clips . One side was easy to get to but the other not so . So I installed the wristpin clip on that side then slid in the wristpin through the rod and piston . Make sure the arrow on top of the piston is pointing to the exhaust pipe . My first BBK I had a wristpin clip pop out and it ate up the head , piston and cylinder so make sure they are in nice and snug . Use plenty of 2T oil or engine assembly lube on the piston . Squeeze the rings to get it started and there should be an opening underneath as the bottom had two arcs instead of a complete circle at the base . Once you have the cylinder on past the 2nd ring I had to gently use a rubber mallet to tap it down . The head is made so it only goes on one way . Installed the nuts and with a 2nd torqueing . I installed the pipe which was two bolts at the head and two at the rear . I did have to get two shorter bolts since the mounts were thinner and used several washers since it was hitting the wheel . I used M8 -125 bolts from Oreiilys . I put in a larger main jet and fired it up . It started up and I let run for a few minutes at idle and revved it up just a lil bit then shut it down . I retightened the nuts to be sure then put the fan shroud and body back on . The first time took me an hour as I was being careful but the 2nd time I started and was riding in 30 minutes . A 2T is by far easier since no cam chain or valves to deal with . I used this kit http://shop.jupiterscooters.net/Cylinder-kit-75cc-Minarelli-10mm-wrist-pin-Made-in-Taiwan-MGMP0108-75CC-10mmpin.htm Note some use 10mm wristpins some 12mm .

250 for the BBK , a pipe and labor , is not bad providing they also upjet the carb . The kit was on sale at Amazon for 90 with 20 for shipping and my dealer had one for the second time for 135 on the shelf instead of having to order it . A 2T pipe can run from 150 to 400 for the high end brands . Note my pipe is waaaaaaaaay louder than the stock one as it makes my ears ring if I max it out . It sounds like a Yamaha YZ 80 where stock was a loud weedeater . I would do it myself since Im a miser and experienced in wrenching , but if your not and lack the tools and area to work in then have the shop do this . I did have to get heavier sliders as 5gs were fine for the 50 but too light with a BBK . I went with 8g but I can still hit 9k RPMs going up a steep hill with a running start . I put in Hoca 1.5k clutch springs since the 8gs takeoff was much slower but I was wanting to reduce the RPMs at cruising speed as it redlined way too easy even up hill . I also installed a Hoca bb torque base since the BBs prevent the torque spring from binding . I tried using a 1.5k torque spring but could not compress it so I resused the stock one . With the bb base it seems like I have more " gears " as shifts are so much more smoother . Here it is http://www.partsforscooters.com/169-281_Hoca_Torque_Spring_Base?sc=11&category=74117

You can buy a power kit which has the BBK , pipe , carb , intake and CVT parts for 499 like this http://www.partsforscooters.com/169-210_Power_Pack?sc=34&category=133366