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View Full Version : what size carb and make for 1988 trx 250r



jrothernel
11-13-2006, 08:14 AM
After reading some post in here, I am still in the dark regarding aftermarket carbs for my bike. What is a good carb to switch to, and what size 36, 38, or 39. I am looking for something that will be easy to jet and give me good performance. My bike is pretty much stock. I do have a FMF fatty with power core silencer and a reed spacer. I just bought the bike last spring. I am the second owner. The first owner only used this bike for the first summer back in 1988 and it has been in storage untill i bought it last year.
Any thoughts would be a great help.

ZRider400
11-13-2006, 09:12 AM
go with the keihin 38 a/s carb.

C-LEIGH RACING
11-13-2006, 10:18 AM
& get rid of the reed spacer.
You dont need more crankcase volume on a stock engine cause thats all it does.
Neil

jrothernel
11-14-2006, 05:22 AM
can you give me a bit more information on 38 S/T carb and what is does to help performance, and what kind of jetting is required for this bike. Thank you

hontrx265r
11-15-2006, 01:58 AM
The 38mm airstryker carb will mainly give you a much better mid to top end pull. THe low end maybe slightly sacrificed due to lack of engine modification, but not a bad thing by any means. What you will gain throughout the rest of the RPM range will out weight the low end loss. If you port your engine, remove the air box top, and maybe get a better pipe will take care of the soft low end and greatly improve engine performance in all RPM's.

jrothernel
11-15-2006, 07:16 AM
Thank you for all your help. I am sure I will asking more questions in the near furture

iamjasyn
11-15-2006, 04:55 PM
Originally posted by C-LEIGH RACING
& get rid of the reed spacer.
You dont need more crankcase volume on a stock engine cause thats all it does.
Neil

Ah! Is there a way to get rid of that spacer when you're running a 38mm carb and the associated shorter boot and still get to match up with the airbox? I guess you'd just need a longer intake manifold. My guess is on a 270 with cyl spacer it's just making the charge through the transfers lazy.