I have an '86 Honda 250R ATC. I want to give it more power for trail riding and hill climbing. I already have an FMF gold series fatty pipe. I was thinking of getting a fat boy silencer with the V-Force delta valve. What kind of power gains should I get from this combination? Is it a good combination? Is there anything else that I should consider changing as in pipe and valve combos? Should I just get the Fmf silencer and ram or rad valve? I don't want to open the motor up or anything, but when I took my stock reeds out I think someone ported it slightly. And one more thing, does anyone know the stock bore for an '89 suzuki LT250R? My friend wants to bore his and needs to know the stock bore measure as in with a micrometer. Any help would be appreciated.

 

I would get an FMF silencer since you have the pipe already. There isn't a big power difference between silencers. Go with the Boyessen Rad Valve and Carbon Fibre reeds. This is what i have and i love it. I have got excellent throttle responce and the rad valve gave me a lot of power all the way through the power band.

 

event tho I don't have this setup (am buying it as soon as I get some more cash) I have heard many many many people recommend the V Force Delta reed cage...power gains all the way up the powerband, and this is something neither then RAD or RAM valves do...

 

Well I would suggest a slightly bigger carb and the V-force reed cage. I have spoken to 2 different people who own all the different reed cages and suggest the V-force over any (although it isn't cheap). I personally have the FMF with a reed spacer. As far as silencers go I think you would be hard pressed to notice much difference between the FMF and duncan so get the cheaper one.If you don't mind running slightly better gas get the head milled by a reputable shop to bump up your compression to around 200 PSI this will give you better punch and you will like it much better with the exeption of having to run a 50/50 mix of pump and race ga$$$. Personally I don't lik the FMF fatty on stock engines its too weak off the bottom and really doesn't work well unless you have a motor that revs out better than a stock ported motor does. I like the Duncan Race or the CT for stock engines. They work great on stock and mildly ported engines. I don't know if you are willing to change pipes but its just a thought. To answer your first question the stock bore on an '89 LT250R is 67mm. Hope this helps,

CT250R

 

I have to agree with CT250r. The best bang for your buck at this point would be to up the compression and put a bigger carb on it. The stock reed cage works very well, just put some better reeds in it and you'll be very pleasantly suprised by the power gain. Any of the Paul Turner pipes for this bike are AWESOME and the best sounding silencer in my opinion is the fat boy.