Stan please compare the distance from the top of the exhaust port to the top of the cylinder. I'm thinking the E distance might be greater than the A.
Please also have a look and see if the conrods look different. I remember reading that one of the improvements that came with the B model was a lighter conrod compared with the A. I think this might be right too because my B and D motors have much less motor frequency vibration than the A.
TY250 E Piston
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Re: TY250 E Piston
Hi David
I measured up most dimensions on the A & E cylinder and taped off the transfer ports and measured their volume by filling with water. I have attached the scribble results. From results conclusion is from the outside they look different but inside they are quite similar. Will investigate the crank and crank case volume next.
Cheers
Stan
I measured up most dimensions on the A & E cylinder and taped off the transfer ports and measured their volume by filling with water. I have attached the scribble results. From results conclusion is from the outside they look different but inside they are quite similar. Will investigate the crank and crank case volume next.
Cheers
Stan
Re: TY250 E Piston
Hi David
Finally got around to checkingthe bottom end of the A vs E
I have both with the cylinder off at the moment.
Filled both cranks with petrol and got close to 490ml in both so not a great difference there.
Crank wieghts on E may be very slight ly thicker but only by 1mm.
Con rod on the A has markin of '311" and is 8mm thick
Con rod on the E has "498" marking and is 6.5mm thick
I got an original piston from Ebay and I believe it is a DT piston. It is almost 30gms heavier than the original Piston.
I will let you know how it goes.
Cheers
Stan
Finally got around to checkingthe bottom end of the A vs E
I have both with the cylinder off at the moment.
Filled both cranks with petrol and got close to 490ml in both so not a great difference there.
Crank wieghts on E may be very slight ly thicker but only by 1mm.
Con rod on the A has markin of '311" and is 8mm thick
Con rod on the E has "498" marking and is 6.5mm thick
I got an original piston from Ebay and I believe it is a DT piston. It is almost 30gms heavier than the original Piston.
I will let you know how it goes.
Cheers
Stan
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- Champion
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- Joined: Thu Jun 05, 2003 7:01 pm
- Bike: Many Twinshocks
- Club: CQTC Inc, RTC Inc
- Location: Gladstone, Queensland
Re: TY250 E Piston
Stan I'm amazed that the port timing was so close between your TY250A and TY250E cylinders. I'm wondering if your A model is of a later type to mine. My A model has a very low ID number so I think it is an early one.
The first photo shows the front of the cylinder on my TY250A. Does your A cylinder have the flat round bit above the exhaust pipe like this one, or does it look like the cylinder in the second photo (which I think is an early B model cylinder) with the fins going all the way across the front?
David
The first photo shows the front of the cylinder on my TY250A. Does your A cylinder have the flat round bit above the exhaust pipe like this one, or does it look like the cylinder in the second photo (which I think is an early B model cylinder) with the fins going all the way across the front?
David
relax, nothing is under control
Re: TY250 E Piston
David, I have 2 434 cylinder and none of them as that flat round above the exhaust.
Guy
Guy
Re: TY250 E Piston
Hi
My A has the flat bit. So the major difference that is obvious is the con rod and the piston weight. Maybe some small portimg difference that are not so obvious. Would be great to get the porting specifications!
My feeling is the gearbox is a contributor to the performance difference but have not studied it.
Cheers
Stan
My A has the flat bit. So the major difference that is obvious is the con rod and the piston weight. Maybe some small portimg difference that are not so obvious. Would be great to get the porting specifications!
My feeling is the gearbox is a contributor to the performance difference but have not studied it.
Cheers
Stan
Re: TY250 E Piston
Hi
I ended up purchasing a DT piston Kit from ebay USA. Got the cylinder rebored and checked the ring gap. 2nd ring was 26th so not happy as standard was 16.
As mentioned before my original piston was 218 gms and the DT was approx 246. The TY has a noticably thinner skirt so i hacked off about 10gms with a die grinder. As mentioned by Guy the TY shirt is also cut back slightly so I did that.
Bought a set of TY rings from ebay and they were better but still out of spec. So the rebore guy must have got it wrong. Also the new TY top rings stuck a bit in the DT piston groove. DY piston kit came with two sets of under piston springs. According to my TY parts manual the TY has only one spring under the second ring. I installed a spring under the top ring and this stopped the sticking.
Not real happy again but not about to waste a piston and rebore so installed the DT piston and rings gave it a test run last weekend and it went pretty well.
Just a warning to watch what you get from ebay. Also I would go for a TY piston next rebore over a DT for the lightness.
Or just get a wiseco one.
Cheers and thanks for your input.
I ended up purchasing a DT piston Kit from ebay USA. Got the cylinder rebored and checked the ring gap. 2nd ring was 26th so not happy as standard was 16.
As mentioned before my original piston was 218 gms and the DT was approx 246. The TY has a noticably thinner skirt so i hacked off about 10gms with a die grinder. As mentioned by Guy the TY shirt is also cut back slightly so I did that.
Bought a set of TY rings from ebay and they were better but still out of spec. So the rebore guy must have got it wrong. Also the new TY top rings stuck a bit in the DT piston groove. DY piston kit came with two sets of under piston springs. According to my TY parts manual the TY has only one spring under the second ring. I installed a spring under the top ring and this stopped the sticking.
Not real happy again but not about to waste a piston and rebore so installed the DT piston and rings gave it a test run last weekend and it went pretty well.
Just a warning to watch what you get from ebay. Also I would go for a TY piston next rebore over a DT for the lightness.
Or just get a wiseco one.
Cheers and thanks for your input.
Re: TY250 E Piston
Hi Stam
Be warned, the Wiseco piston are not what they use to be, a friend bought one and got a China made '' object '' less than perfect
Guy
Be warned, the Wiseco piston are not what they use to be, a friend bought one and got a China made '' object '' less than perfect
Guy
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