Autissa 190 big bore kit,fitting advice needed

[rich3648]

purchased a 190 cc big bore kit for my rd125lc and wondered if anyone could give me advice on changes to carb after fitting,do i need to up jet or fit a complete different carb.

any other things i should worry about,crank? different oil?etc

thanks in advance if you can help

cheers
rich

[LC'Adam]

Well, the bore kit will have been designed to work with the standard carb.

First,

What carb do you have, 10w or 12a (this has a big factor in the jetting), are you running a pipe and standard airbox?

And, if this is the kit I am thinking of, off ebay, then it has a skimmed head with it so it is worth checking the squish with it all bolted down.

Glad to help you mate.

Adam

[rich3648]

i have a bike with a 10w carb,micron power
and a 12a with a allspeed,both running with standard airbox.
sorry what do you mean by the squish adam.
cheers

[LC'Adam]

Yes, you have a point there gaz,

The point I was making is that if the squish is tighter than 1.4mm then it is advisable to use higher octane fuel (to prevent detonation). As always Rich, use the best oils for the best performance and protection (Castrol TTS or Silkolene Pro Comp 2).

Crank will have a longer life if any thing because you won't have to rev it as hard to get the power out.

If I were you I would fit the autissa with 10w carb, airbox and micron. Start with a 220 main and come down accordingly (plug chops don't lie).

If it doesn't run right, play around with different carbs, air filter set ups and pipes.

Don't forget to turn your oil pump up as well mate.

Or you could remove the pump and premix the oil/fuel. I prefer to do this but its up to you

Adam

[rich3648]

cheers guys will let you know outcome when the snow leaves

[twostroker]

when them autisia kits are on standard bore arnt they 175cc and not 190cc ?

if memory serves me right satndard 125lc bore size is 56mm and autisia bore size is 66mm,
at 2mm oversize i think they produce near on 180cc,like adam said squich should be checked plus if your looking to gain a few bhp id get the ports done as porting on them autisa barrels has alot of room for improvment but straight out the bok they do claim to be 28bhp.
when i first fitted my re-sleeved bigbore top end (not autisia) on my 125lc it ran crap and made 13bhp on a dyno as it was a big mis-match of parts mainly the swarbrick pipe was strangling it so keep it simple and if possble put it on a dyno to see what it makes,arter a decent carb set up and a 1 off pipe mine made 30ish bhp which is over double the first dyno run.

standard 26mm carb and exhaust will allow it to run ok but in a ideal world a pipe designed for the spec of your new barrel and a 28mm carb will make it alot quicker.mine felt mental to about 80mph after it was all set up.

[billy]

66mm bore on standard crank gives 170cc.

+2mm bore gives 181cc.

[JonW]

I always thought these kits were meant for a bigger carb. I know you can make it work with the standard unit, but back in the day I was always told that you'll get more from it with a bigger carb/zorst combo.