250 cylinder base gasket

[little_wing]

hey so the factory cylinder base gasket... what thickness is it. 0.3mm , 0.4mm , 0.5mm ??????
I am looking for what comes from the factory.....

second question what are most people that are riding at sea level putting...

I do have a squish tool that the beta engine service manual suggests. but I am just wondering what to order

the Athena top end gasket kit only comes with a single base gasket which is 0.3mm where as the kit from beta comes with 0.3mm through to 0.6mm
also where can I get just single base gaskets other then beta,..... Athena only makes 0.3mm for 250/300 betas.

[twowheels]

Beta makes the gaskets available in the kit and individually - why do you need another source?

[aj_mariner]

I would bet thickness is different between the RR and RE 250’s...just like the 300’s.
You will want to maintain the spec in the engine service manual for deck height, which is part of squish but not the same number. RE’s will have deck height close to zero...RR’s will have a 0.1mm or 0.2mm thicker base gasket.
If the piston protrudes from the cylinder then you need to increase gasket thickness.
New gaskets compress 10%...so a 0.5mm will be 0.45mm when cylinder is torqued down.

I don’t have a 250, but my 300 uses a 0.5mm gasket and the deck height is damn near perfect.

[typeone]

i believe i measured mine when i went thinner, i'll see if i can find the notes...

[NW_250RR]

My 17' 250rr had a .6mm base gasket stock. Squish measured 1.8mm. I had it cut to 1.2mm. Big difference.

[little_wing]

My 17' 250rr had a .6mm base gasket stock. Squish measured 1.8mm. I had it cut to 1.2mm. Big difference.

something tells me your confused with a measurement.... you suppose to have less then 0.10mm

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[NW_250RR]

My 17' 250rr had a .6mm base gasket stock. Squish measured 1.8mm. I had it cut to 1.2mm. Big difference.

something tells me your confused with a measurement.... you suppose to have less then 0.10mm

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Nope, not confused.. I just measured my squish band with solder.

[aj_mariner]

Little_wing...squish and deck height are not the same thing. I think that is where the confusion is. Your picture is showing a deck height measurement. Squish is determined by the dome and the deck height

[little_wing]

Little_wing...squish and deck height are not the same thing. I think that is where the confusion is. Your picture is showing a deck height measurement. Squish is determined by the dome and the deck height

I stand corrected, I am new to motor work, I had the terms mixed up.

I don't believe I read anything in the beta engine manual about squish. thinking about it a different base gasket would change the squish slightly. and I also read that some people have their heads machined to change the squish..

I am not a super fast rider and think my bike ran ok. I am at sea level. is there any reason to change my squish?

[NW_250RR]

Little_wing...squish and deck height are not the same thing. I think that is where the confusion is. Your picture is showing a deck height measurement. Squish is determined by the dome and the deck height

I stand corrected, I am new to motor work, I had the terms mixed up.

I don't believe I read anything in the beta engine manual about squish. thinking about it a different base gasket would change the squish slightly. and I also read that some people have their heads machined to change the squish..

I am not a super fast rider and think my bike ran ok. I am at sea level. is there any reason to change my squish?

Getting the head cut isn't really about power, but a cleaner / crisper running bike. The result is a little power bump yes, but the most important thing is how connected the throttle is to your hand. Jetting is much easier and more tolerant. I know some guys will go to smaller base gasket (.3mm) but the optimal way to do it is to have the head cut. Cost me $65.

Im at sea level as well on my 250RR. I run 13/51 with the squish corrected and a slightly stiffer PV spring to tame the fast revs with the shorter gearing.