any one running 3rd gen carb on a 2nd gen 250r.

[Erock86]

read on another site that its a good ideal but does anyone here with a 2nd gen 250r have a 3rd gen carb on there bike.
if so is it as simple as just switching them out or do i have to do mods for it to work and run good.

i tried using the search engine but i couldn't find anything.

[JasonB]

It's an upgrade forsure, I had an 86 carb on my 84 250r carb.

[Erock86]

was it as simple as taking the 84 off and putting the 86 on or did you have to modify anything to make it work.

[JasonB]

It came on the bike but it just slips into the stock boot. I think the throttle cable even works from the 84 on the 86 but don't quote me on that.i did have to switch to an fl350 intake boot when I jumped up to a 39pwk, no amount of boiling would get that stock intake to accept the 39mm carb lol

[Erock86]

any one else have any experience doing the swap from stock to 85-86 carb if so was it just as simple as switching or do i have to do any mods to make it work.

also jason did you see a big diff from the 3rd gen carb to the 39mm carb and would it be ok to run that with (for now)stock motor.

[manbearpig]

i run 85R 34mm keihin round slides on both of my 82R race bikes. these have the same exact motor as your 84. my motors have been ported and the heads have been milled. i have run both the stock 83/84 30mm Keihin and the 85R Keihin carbs on both bikes and have seen a good improvement with the larger carb. i have aftermarket intakes on both bikes, so all i had to do was buy the proper size swappable boot and i was ready to go

to fit the 34mm carb (round or flat slide) in your stock OEM 30mm boot, you'll need to remove the boot, heat it up in boiling water, and stretch the boot to fit over the mouth of the carb. not hard. people do it all the time

as far as the throttle cable, you may be able to use the stock cable, but im not 100%. i have twisters on both bikes that run these carbs. the cables for the twisters are adjustable so i can just dial it in on the fly if needed.

[Erock86]

thanks im gonna definitely get one for my 84 ill try boiling the boot. I was thinking about getting twist throttle myself can you pick up a universal one or does it need to be specific to fit.

[ATC ADDICTED]

I have also , many of times , wondered this same thing... what all is involved with updating to the 85-86 carb on the air cooled 83 250r

[manbearpig]

I was thinking about getting twist throttle myself can you pick up a universal one or does it need to be specific to fit.

http://www.ebay.com/itm/Motion-Pro-Twist-Throttle-Kit-Honda-ATC-250R-81-84-/330303614012?pt=Motors_ATV_Parts_Accessories&hash=item4ce7a12c3c&vxp=mtr

this kit right here includes an adjustable cable. i have this same kit on both of my bikes. twisters are great, until youre riding in really bumpy terrain, very fast, and youre tired. that is a recipe for disaster, just be careful getting used to your new throttle.


I have also , many of times , wondered this same thing... what all is involved with updating to the 85-86 carb on the air cooled 83 250r

you will need: carb, adjustable cable, and an FL350 intake OR you'll need to modify your existing boot using the method described above. you will also need to make a new or adapt your existing carb to airbox boot if you're using the stock airbox.

simple conversion, and you'll feel some improvement, but you'll get max benefit if youre ported, piped, and have aftermarket reeds. flow baby flooooooooooow

[Erock86]

thanks again for all the info i was planning getting carb and possibly pipe as soon as possible then this winter pull the motor have it honed new piston rings and reeds im not super techy learning as i go maybe ill get it ported if i can find a decent shop around here.

[xr650r]

How are you guys jetting yours?