et2 rat project.

50mph top speed,gear up?

 

hmm shouldnt it be going abit faster with a 70kit? My old et2 50 was hitting 45mph stock, My zip70 is hitting about 60mph with standard gearing, so shouldnt an et2 be about the same since they use a zip engine? Unless they geared et2 engines for less topspeed? cratch:

 

SimonT had a similar problem,gear up fixed him

belt might be slipping either, theres some thread coming off on one side of it so i urgently need one.

 

Republic of Ireland :grin:

 

Yeh try a new belt and maybe some new rollers too (different weight). A gear-up on just a sport 70 sounds too overkill unless your wanting to sit at higher speeds for long periods of time without over-revving the motor.

 

well i got the polini reeds in today, so i went out and was cruising at my 50mph/full throttle and did a plug chop, slightly lean at full throttle but fouling plugs when left ticking over for a while (longer than you should leave a 2t tick over anyway so im not too worried)


jetted up as far as 85 and the plug is reading a little rich but my 0-30 has increased and top speed is the same 50mph. needle is down 2 notches from where it was at the top to 1 from the bottom of the needle. and the mixer screw seems to be in the right place so im happy enough with the carburretion set up till i get an 84 and 83 jet

I think the tranny may be set up wrong alright, have 5.5 gram rollers in it, the revs stay constant from the time the clutch locks up until about 40mph when they start to climb upto 50mph. do i need lighter rollers? I have 4.5 and 4.8 sitting here. but if the size needed would be inbetween im happy enough with it like this until im order the jets,

im running a b9es plug up from the b8es of the stock plug and ive turned up the output of the oil pump, anything else that should be done?

 

Try a set of 5gram rollers, thats what im running in my zip. I was using 4.4g before (same setup in sig), and it felt too light. Pulls much better with the 5g rollers now. (With the 4.4's it was just revving its tits off and not accelerating as quick)

Now it sits nice in the powerband (im using a ZX too), all the way upto 45mph then it starts winding out to topspeed.

 

may aswell try the 4.8's then since its what i have here, anyway taking it on an egg run tomorrow so ittl have to wait until sunday or next week.

 

egg run went well, even won a prize :cheers:

 

Haha brilliant! Did you try the 4.8g rollers?

I dident realise you were that big! (not being rude), 50mph would seem normal with your rider weight. Im as skinny as a rake! (9 stones, 55kg or so lmao), so thats probably why im getting around 60mph on my zip with the same setup as your ET2! :thumbsup:

Good luck I hope you get it going well! Report back!

 

nope still on 5.5, getting a lend of an impact gun tomorrow. so ill keep yas updated.

 

4.7 on now. feels alot lighter but revs are constant upto 50mph so theres improvement but the torque is down a little, accelerated a BIT faster. id say 5,0 would be a good number for me alright. still need that belt, its starting to shred after yesterday :blink: more than likely slipping, id love to get 55mph out of this as thats what i got out of my completley stock et4.


im guessing my choice of kit would also have an effect the top speed(well obviously it would)
and theres me weight but thatll be gone in time. my mate had a bomb around the local industrial estate and hit 55 before he ran out of road.

 

Ye slightly heavier on the rollers will drop the consistent rpms but increase torque slightly, may be slower off the line but the power will be meaty in the midrange-topspeed area.

Have you had the cases ported and matched to the 70kit? If not maybe this should be the next step along with a little cylinder porting if you dont want to upgrade to a midrace kit.. Or maybe upgrade the DR kit to a Polini or Malossi sport 70. These make a little more power than the DR, with your 21mm carb it should go well, with cases ported and matched your looking at 55-60mph without gearup, and 60+ with gearup!

 

its an option but an expensive one at that, dont know anyone that good with auto stuff over here but theres loads of vespa tuners about.

 

I think Minor offers a porting service! Might be worth dropping him a PM, porting will really open your engine up and make the 70 perform how its supposed to.

 

still its a lot of hassle taking my scoot off the road for a while and the cost of sending bits of it overseas, that said, might be getting a dragster on the cheap soon enough so i might consider it then

 

thinking about doing some porting on the dr, and getting a gearup seems like the next step. (gear up would cost some acceleration but could this be gained back with lightening the rollers?)