300 big bore for air cooled R.

**Blown 331** · 12-06-2004, 03:40 PM

Does anyone know anything about the big bore kit for an air cooled R? Can you still buy pistons for them? The cylinder is a factory Honda part, correct?

**ejc042** · 12-06-2004, 04:48 PM

Yes, the 300 kit is a factory Honda option. No the pistons are no longer available. I am still trying to find one for the 300 kit I have.

**Blown 331** · 12-06-2004, 04:59 PM

Let me know if you find a piston, I think I'm gonna buy the kit and start looking for a piston my self. I've heard of YZ250 pistons in a 250R so I bet just about any 2-stroke piston with the same bore can be made to work. Do you know how many milimeters the piston would be? How many times can you over bore it?

**ejc042** · 12-06-2004, 05:14 PM

76.00mm is stock and it can go out to 80.00mm
Good luck with finding a piston.

**350x'inNY** · 12-06-2004, 05:35 PM

Hmmm... if you have the "kit" it should be included. I've got a 300R head here. Saw a guy have a huge motor lot in Cali a month or so ago that had a 300R jug with it. He wouldn't seperate it and I wasn't going to buy 6 motors to get the 300R jug.

Bruce

**Blown 331** · 12-06-2004, 05:50 PM

Well if you have a kit with a standard piston that is worn out you still have a kit and you still need a piston.

**350x'inNY** · 12-06-2004, 05:57 PM

Yep... good point. I thought you might have bought that kit that xownerx had. When you said kit I assumed it was new never installed.

Bruce

**Blown 331** · 12-06-2004, 06:07 PM

I don't have it yet but I know where I can get one. How much do you think the cylinder and head are worth? What is different about the head? Larger diameter combustion chamber or what? I probably shouldn't even wast the money if I can't get a piston.

**Trikeaholic** · 12-06-2004, 07:47 PM

call LA sleeve, they can sleeve it and supply a piston for it too. Most 300 kits have been bored out to the max, so they figured out how to sleeve them and supply pistons. Prolly not worth the cost though.

**RideRed250R** · 12-06-2004, 09:26 PM

well both CT and TRINITY RACING has machines capable of making pistons, also trinity racing told me that they can make a piston for out dated big bore kits.
adam

**ejc042** · 12-07-2004, 09:17 AM

Everyone I talked to said fjor around $500-$600 they could resleeve and supply a new piston. they actually use a water cooled 330 kit to make it happen.

**BLAZERONE22** · 12-07-2004, 11:13 AM

If the cylinder has any bores left on it you can also trim the skirts off a fl350 piston and go that route.

**Troll 2** · 12-07-2004, 01:44 PM

Then there's two 350cc oddy's. The early version is 329cc and thats the one that should work................

**MTS** · 12-07-2004, 02:14 PM

how much do you have to trim off the skirt on the oddy pistons to make them work? and if that works for the 300 kit, will a fl250 oddy jug and piston bolt up to a 83 R bottem end?????

**deathman53** · 12-07-2004, 07:51 PM

I hate to bring this up, but awhile ago wasn't there a person who needed 15 more poeple so he chould have pistons made. I belieive the piston, rings, and such were gonna cost $200. Did he ever get the people he needed to do this?

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300 big bore for air cooled R.