88cc bore lengths

[Chronic]

well ive made a ****-up and have got a 12 volt 88cc bore! i got the kit a year ago!

i have a 6 volt '75 CT70

Can someone please tell me what the difference in lengths are??? i can get it machined for nothing so only have to know what to cut it down too

HELP

 

[motodevo]

12v rod is 3mm longer than 6v rod(94mm vs 91mm) and the piston deck is 3mm shorter on the 12v piston(17mm vs 20mm). The barrels are the same. Good news is you just need a new piston(30/40 bucks), If you machined down the barrel you'd need a custom timing chain

Edit: Just saw you avatar, didnt twig when i read 75 ct70, Mighty Green is my fav dax colour, mine's in pieces waiting to be made pretty again

 

[Chronic]

thanks! my mate had a look and 3mm is what we figured it was out! so i just need a another piston!

 

[Chronic]

oh but the chain is tight to get on now! with the adjuster out!

 

[motodevo]

If its a new chain it will be tight as all hell to the point you'll struggle to get the cam gear on. As long as you have the chain seated correctly on the crank,oil pump gear and tensioner gear you'll be fine. Make sure the oil pump gear is in line with the other 2 gears when looking through the cam chain cutout, if the oil pump gear stick out 1mm or 2mm further away from the case than the other 2 just spin it until it goes in and locates on the oil pump pin. They stretch a little in the first few runs. After a few runs readjust the tensioner and tighten the nuts on top of the head as the will need it after a few heat cycles. It spun me out how tight the first camchain i put on but loosened up within 10-15 mins of running

 

[Chronic]

If its a new chain it will be tight as all hell to the point you'll struggle to get the cam gear on. As long as you have the chain seated correctly on the crank,oil pump gear and tensioner gear you'll be fine. Make sure the oil pump gear is in line with the other 2 gears when looking through the cam chain cutout, if the oil pump gear stick out 1mm or 2mm further away from the case than the other 2 just spin it until it goes in and locates on the oil pump pin. They stretch a little in the first few runs. After a few runs readjust the tensioner and tighten the nuts on top of the head as the will need it after a few heat cycles. It spun me out how tight the first camchain i put on but loosened up within 10-15 mins of running

yeah it was all new! and was tight as hell! righto ill get a piston organised!

 

[Chronic]

sent some emails and i have the wrong piston! organising a new one asap

Thanks Motodevo you have saved me money and a head ache

 

[motodevo]

No worries, I only know because my mate did the same thing with his z50

 

[Chronic]

soon as i saw the pic of the piston and the measurements i knew you were right!