Questions RE: "B" Cylinder

[PBWR450]

I am aware of the reason for different sizes; A,B,C etc. but my questions are:

1) My 2000 EC250 cylinder is stamped with a "B" above the intake. Who would have stamped it and when? Did some bikes come from the factory with different sizes or was this a replacement/refurbished cylinder?

2) Could this cylinder be re-plated to accept an "A" piston? My reason for asking is because my internet research has shown a considerable price difference between the A and B piston. I was also told by a GasGas shop that Wiseco only makes an A, although I know there are other brands.

Thanks

 

[2 strokes 4 life]

Vertex forged pistons make A,B,C,D. Yes some cylinders came as a B size from the factory and finaly yes you can re-plate to a A size if you wish. Good Luck.

 

[jostby]

I just had my kids bike replated to an "A", it was a "B" previously. Millenium did it and it turned out excellent. I installed a Vertex "A" piston, worked out great. Some of the Wiseco GG pistons being sold (E-Bay) don't seem to be the correct size so I would be careful going the Wiseco route but others here do without problems but they probably buy from GoFasters or another GG dealer.

 

[PBWR450]

Thanks for the replies. I had US Chrome replate a Husaberg cylinder and it turned out well, I have also read alot of good things about Millenium. I assume Millenium would need the new piston sent in with the cylinder? Where is a good place to purchase the Vertex pistons?

 

[jostby]

I got mine shipped for $85 total from http://promotorsports.homestead.com/ They were able to tell me the size and I was able to determine it was an "A" with that info. I don't know why they had it but they were selling some other GG stuff on ebay at the time too (still might be) but they aren't a GG dealer from what I have been told. And yes, I sent it with the cyclinder. But I think Millenium offered to supply either Vertex or Athena, both good choices.

 

[dave948]

"But I think Millenium offered to supply either Vertex or Athena, both good choices."

All three companies mentioned above are some of the best out there. If you need to get it re-chromed then yes, get the piston first and send with the cylinder or buy it from the the refinisher.

I wouldn't think that a replate would save money over an "A" or "B" piston price, but I've been wrong before. I've seen and heard some amazing stories about cylinder bore life with the Gassers as long as good oil is used and air filters are cleaned often. You may not need a replate, have it checked out and save a few bucks.

A lot of people with gassers want that "A" bore and will spend money to get it. Fact is you don't need it and wouldn't even have it with other brands. It's just a way for the factory to compensate for manufacturing tolerances that most OEM's consider acceptable.

They made it simple for us, if you have an "A" run an "A" if you have a "D" run a "D" and be happy you have one of the best bikes built.
This isn't high school were an A is better, the guys running the "D" have more CC's than the "A". At least that's how I like to look at it.

 

[jostby]

Dave948, in respose to:

I wouldn't think that a replate would save money over an "A" or "B" piston price, but I've been wrong before. I've seen and heard some amazing stories about cylinder bore life with the Gassers as long as good oil is used and air filters are cleaned often. You may not need a replate, have it checked out and save a few bucks.

In my case I found an "A" piston much cheaper than normal. And since my kids cylinder got dusted bad (the airbox boot was not all the way sealed on the carb) it had to be replated. No differance in the replating price (A or B size) so bonus for me.

They made it simple for us, if you have an "A" run an "A" if you have a "D" run a "D" and be happy you have one of the best bikes built.
This isn't high school were an A is better, the guys running the "D" have more CC's than the "A". At least that's how I like to look at it.

The bonus here is that as I end up re-ringing or changing pistons as routine maintenance/wear compensation I can continue to use slightly larger pistons as needed. If this was a "D" cylinder you would not be able to compensate with an oversize piston. So at least in my opinion the "A" is better. But you know what they say about opinions!!

 

[PBWR450]

Dave948,

Thanks for the reply. I had thought about the fact that buying a piston (even a different size) would be cheaper than replating however, if the cylinder does need repaired my logic (which often ends up costing me a bunch of money) is that if it's possible to replate to "A" specs. then subsequent rebuilds would allow me to start at a "B" size piston, providing the cylinder is not damaged.

I have not torn into the motor yet, I just bought this bike and it has good compression and runs strong, but given the general maintenance neglect it had suffered I am just hoping for the best but preparing for the worse.

 

[widebear]

Dave948 is correct in his appraisel. If you think you can just keep putting larger pistons into the same bore as it wears, you need to consider that the cylinder will not wear in a symetric manner it will eventually become barrel shaped ,loose and out of round at some points, while remaining much the same as new in other spots. Athena piston micro sizes are tha same price whether a,b.c. or d.The benifit of having a A or standard bore 250 is that you have a wider choice of pistons because you can now use a $70.( pro x piston, 86 to 96 honda cr-250) if you want.Take a look at monkeybuttparts .com for listings