81 250R Modding Question...

[250rCRazed]

Hey guys, so I decided to take apart my 81R and have the cylinder honed, head milled and some port work done. The trike still has the stock (28mm?) tiny carb on it and if I do this work I'm definitely slapping a 34/35mm carb in there, my only problem is finding an intake boot on the cylinder side (and possibly air box side) that will fit this carb. I've done a search on here and it seems that the 83-86 are interchangeable but not the 81-82?? Any help on this would be great, and even better if you have anything you could sell me. Thanks guys.

[250rCRazed]

also if anyone has a nice 34mm Keihin PWK or similar carb I may be interested in that too.... but I'm hoping someone can chime in on my question above.. I know some of you have gone through this ordeal before.... the rubber intake feels so dried and hard its like plastic and theres no way I'm stretching it to fit the bigger carb

[cr480r]

Ebay.. A a kdx200 has a 35pwk, kdx 220's have 33pwk's.

[250rCRazed]

Ebay.. A a kdx200 has a 35pwk, kdx 220's have 33pwk's.

ok, but what about the intake boot question... on the reed side... what intake bolts up to an 81 Air cylinder that will fit the 35pwk?? the one on there is so tiny and dried out

[200xman]

The 81 - 86 intakes will all interchange. On mine I lucked out and found an oldschool aluminum intake with a boost bottle nipple cast in. I am running a 85R carb connected to the intake with a piece of hose But I also have a 300 kit.

[SYKO]

yep all years interchange, also you can use a CR intake and that can change the position of the carb for better fitment on larger carbs, are you sure you want to mill the head?? these motors run hot! and if you up the comp they will run HOTTER! and you may need race gas depending on the amount taken off the head, if your boring it out get some nice port work done to it instead.

[250rCRazed]

yep all years interchange, also you can use a CR intake and that can change the position of the carb for better fitment on larger carbs, are you sure you want to mill the head?? these motors run hot! and if you up the comp they will run HOTTER! and you may need race gas depending on the amount taken off the head, if your boring it out get some nice port work done to it instead.

Well I told the guy that provided I can find a carb/intake setup I will call him and give him the go ahead on the porting. I just knew that with that dinky carb in there porting would be pointless. What year CR intake should I be looking at, and aren't the CR's fitted for 38mm carbs? I'm thinking 38 is a bit overkill for a ported air 250R... I'm watching over a kdx200 35mm pwk on ebay I might pick up.

[SYKO]

I got a 40 mm on an liguid R I dont see why it wouldnt work on the 81, I think the cr's intakes run from 80-89 I think but dont hold me to it.

[mart]

Ive got a 40mm mikuni power jet carb on mine.I to am trying to find myself a pwk for it about 36 or 38mm

[atcsteve]

On my 81 r,I have a v-force cage,85 boot and a 34 mm carb.Its a good combo.My head is milled,and race fuel is a must to run cooler.They can be fast trikes when done right!!

[250rCRazed]

On my 81 r,I have a v-force cage,85 boot and a 34 mm carb.Its a good combo.My head is milled,and race fuel is a must to run cooler.They can be fast trikes when done right!!

I've looked for a V-Force cage for it... where did you go and what did you put in for a make/model. Dennis Kirk didn't have one. The 85 boot I think I'm going to order off of service honda.