LCGB Forums

I have a 150 GP cylinder that has been badly scored by the circlip coming out of one side of piston.
My question - is it worth getting it bored out to 175cc and if so is there anywhere in the West Midlands that could do the work and supply the piston.Clearly cost would be a factor , it may be more economical just to bin and buy a 175 conversion kit. Views/ advice appreciated .
Jono

Readspeed

Did it run ok as a 150? if so just get the next over sized piston and rebore it, 175's are ok but they sometimes can work out slower than a 150 due to poor set up, port size etc

Blimey, something slower than a 150........ It doesn't bear thinking about.

Knowledge wrote:Blimey, something slower than a 150........ It doesn't bear thinking about.

Not so much slower- just hardly much of an increase, GP150 is a sweet little motor, if it ran ok before then why bother changing it?

Thanks for replies- 150 ran ok until mishap , grove in cylinder is deep so thought it might be worth opening out .

Given cost of 175 bore out and potential benefits would it be money better spent buying a 185 conversion cylinder .
Someone told me Reedspeed quoted £300 for 175 bore out and porting , whereas could buy alloy /steel lined conversion kit for £150.
Jono

Jono wrote:Thanks for replies- 150 ran ok until mishap , grove in cylinder is deep so thought it might be worth opening out .

Given cost of 175 bore out and potential benefits would it be money better spent buying a 185 conversion cylinder .
Someone told me Reedspeed quoted £300 for 175 bore out and porting , whereas could buy alloy /steel lined conversion kit for £150.
Jono

if I were you i'd spend big and get an rt195, gt186 or mugello 198. Probably the rt195 for ease of setup.

Take a look at my thread on scooterotica if you want to see some of the complications of buying a simple and cheap cylinder kit.

I wish id just paid the money and bought quality.

I agree with Dickie , many years ago I bought a cheap 185 kit (£100 ish ), spent £40 having it cleaned up only for it to run sh*te , ended up spending another £100 at a reputable dealer having the transfer ports aligned and having it bored to 200cc as it had an oval barrel , and yes it still ran shite not to mention pulling an inlet stud out due to poor alloy !!!
Might be worth buying a quality kit so as to avoid all the hassle

Just for balance, I have a TWE 175 in my first second time around scooter.
With 22 jetex and Af clubby and up geared it would hold its own or better standard 200s.
If I only rode with standard bikes this would be enough. Done loads of 250+ mile rallies no probs.

Scooterlam wrote:Just for balance, I have a TWE 175 in my first second time around scooter.
With 22 jetex and Af clubby and up geared it would hold its own or better standard 200s.
If I only rode with standard bikes this would be enough. Done loads of 250+ mile rallies no probs.

I know what you're saying and of course there are plenty of happy owners with Indian 185 kits running around. And plenty of unhappy owners of expensive kits too.

But on balance I think that in general the old saying of "buy shite and pay twice" holds in this case.

Hopefully it's not always true though as I'm still persevering with my Indian kit.

Thanks for interesting replies - think I will start saving pennies for GT/RT kit sometime next year.
In the meantime I will take damaged cylinder to a suitable establishment and see if a rebore will take out score.
Anybody know of a place in West Midlands that can supply a piston and rebore accordingly, equally what sort of cost am I looking at.
Jono

Jono wrote:Thanks for interesting replies - think I will start saving pennies for GT/RT kit sometime next year.
In the meantime I will take damaged cylinder to a suitable establishment and see if a rebore will take out score.
Anybody know of a place in West Midlands that can supply a piston and rebore accordingly, equally what sort of cost am I looking at.
Jono

Scooter Restorations in Nottingham can supply a mahle piston for about £30-£40 and I'm sure someone in the area could do you a good rebore for decent coin, probably £60-70 for the lot?

Send it to AF buy a piston from them and they will rebore it to suit the new piston for £15

Jono wrote:Thanks for interesting replies - think I will start saving pennies for GT/RT kit sometime next year.
In the meantime I will take damaged cylinder to a suitable establishment and see if a rebore will take out score.
Anybody know of a place in West Midlands that can supply a piston and rebore accordingly, equally what sort of cost am I looking at.
Jono

Can you post a pic of the damage in the barrel?

if its one score it wont be a problem...

My cast 250 barrel has a deep score in the barrel which is the result of a piston circlip coming out about 7 years ago. since then its done many 1000's of miles including 5 euros and produces 30 bhp.

you can see the score above the transfer port on the right in this pic. The pic was taken about 3 years ago and you can see there are plenty of other wounds to the barrel wall too.

Scooterlam wrote:Just for balance, I have a TWE 175 in my first second time around scooter.
With 22 jetex and Af clubby and up geared it would hold its own or better standard 200s.
If I only rode with standard bikes this would be enough. Done loads of 250+ mile rallies no probs.

Crikey, I fitted one of these kits to a mate of mine's LI 125 about eight years ago. Same spec 22 Jetex and AF clubman. Couldn't believe how well it went. (three ring piston from memory). He spoilt it by putting a ScootRS pipe on it in the end. Less easy to ride.

Are TWE still trading?

I agree with Eden though. My latest TS1 touring tune dropped a pin clip after 50 miles, 3 days before leaving for Davos. Nasty score up to the transfers. No Drama, all back together. Done about 4K on that motor since. Makes 25 Horse and 20 Ft/Lb on John Howe's dyno. Plenty for a tourer.