Honda TRX250R Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hi,

My name is Ron and I am new to the TRX250R.net forums, so I thought I would post a question that hopefully you guys can help me with. I recently purchased a Keihin 36mm PJ carb from eBay, thinking it was the stock 34mm carb (the item description said it was). Anyway, I plan to use the 36mm carb on my TRX250R, so my first question is, what do I need to make it work? I did a caliper check on my stock carb and my new carb, and as far as I can tell, the only difference is that the end that goes into the intake manifold and the engine is about .080" or (surprise, surprise) 2mm bigger. The end that connects to the airbox is the same, as far as I can tell. So I'm thinking that the only thing I need is a bigger intake manifold boot. Is this correct? And if so, do you guys know where I can buy one? My second question is about the jetting. I ran a 155 main and a 48 pilot with the 34mm carb, and the bike ran great. My general question is, will the 36mm carb require different jetting than the 34mm carb? For instance, maybe a bigger main or a different pilot? And if so, could you guys give me a ballpark estimate on how much to go? My 250R has a FMF Fatty pipe and Power Core II silencer, and a K&N air filter. Everything else is stock except for a .010" over piston. Thank you all for your time and I appreciate your help.
 

·
Registered
Joined
·
190 Posts
the 36mm will work fine for you and doesnt require you to buy another intake. you can make use of the stock one that you have. if the rubber on your intake has gotten a bit hard you can always heat it up in a pan of water and slip it over the new carb but you shouldnt have to.



as for jetting.... as a base, start with the sizes that are in the stock carb or a size larger. perform a wot plug chop to get a plug reading to whether you are rich or lean and jet accordingly.

HERE is some good reading.
 
1 - 3 of 3 Posts
Top