Does anyone know if the At series (125cc) and the CT series(175) have the same bore sizes?

I often see pistons advertised for both models.

Does anyone know if the At series (125cc) and the CT series(175) have the same bore sizes?

I often see pistons advertised for both models.

Nope different 56x50 on the 125 and 66x50 on the 175.

The STROKE is the same on both. Thats why the top ends will swap over to effectively bigbore the smaller motor. Seeing as they share the same internals more or less it means you have an incredibly strong 125 motor or a perfectly reliable big bore.

Win win situation.

On the parts list there are a 314-.... and 316-..... pistons and piston rings.

Can I assume the 314 refers to the AT series and 316 refers to the CT series?

On the parts list there are a 314-.... and 316-..... pistons and piston rings.

Can I assume the 314 refers to the AT series and 316 refers to the CT series?

Sorry on that i'm pulling a blank. It may well be but be carefull. There are variations like the AT1-m that had only one compression ring. That may be the cause of the different number.

Ordering parts of this age can be tricky. These guy's can help track down some rare old parts.

Fowlers

Although there is no real reason for the later DT Mx piston not to fit.

Fowlers

Although there is no real reason for the later DT Mx piston not to fit.

Aye jase" will the MX barrell fit the twinshock engine ? . & i remember you have a 175 barrell below the bench ?

Aye jase" will the MX barrell fit the twinshock engine ? . & i remember you have a 175 barrell below the bench ?

This is based on the fact that the engines are VERY similar, I can see no reason if you swapped the long studs on the twinshock for the short mx ones that a MX top end wont fit. I havent done it but i see no reason for it not to work. My question would be why, the performance is very similar between the TS and the MX.

. My question would be why, the performance is very similar between the TS and the MX.

It was if i was gonna use my DT125 , for some classics next year, was gonna beef up the engine to 175.,cc, coz its dire.

It was if i was gonna use my DT125 , for some classics next year, was gonna beef up the engine to 175.,cc, coz its dire.

you will go from 13 to 16bhp, seriously that doesent tell the whole story, you will get probably 25%more torque so you dont need to rev her arse off nearly so much. Makes the bike much nicer to ride.

Still left with a realistic top whack of around 55-60 though.