125 special upgrade

[andrewgc]

all,

i want to upgrade the performance of my 125 special engine, not looking for a major speed improvance just power

as i see it i have two options whilst needing to keep it badged as a 125

1/ fit a short bore kit

2/ strip out the mechanics and put a 175 or 150 into the 125 block


which will serve me best?

if its option 1 ( a short bore kit) which is best value for money please ?

[coaster]

I'm not sure what you mean by "short bore kit"? If you mean a larger capacity barrel then there are many options but you will ideally need to upgrade the crank to cope. If you went for an Li150 top end you would get a bit more power which would allow it to pull a 16 tooth front sprocket and should get you up around 50mph or so. As it is, I doubt it will go over about 40-45mph and will be revving its nadgers off.
All depends what you want really and how much you want to spend.

[andrewgc]

by kit i was thinking a mugello.or a BGM or similar ?

[coaster]

There aren't really any BAD kits out there, they all have their devotees so either of those kits would give a significant performance increase. Casa also do one and there is the UK made GT186. All them as I said in the earlier post will need the crank changing to one with a larger GP taper and that will mean an upgrade to electronic ignition. Your gearbox will be good though and a new set of clutch plates should be all that's required along with the bigger front sprocket I mentioned.....oh and a change of exhaust. This lot will set you back in the region of £1000 assuming you do the work yourself

[ToBoldlyGo]

You'll have the GP200 gearbox in there. Changing to 18 x 47 would be an improvement with any extra power.

[Rich Oswald]

You'll have the GP200 gearbox in there. Changing to 18 x 47 would be an improvement with any extra power.

+1