250r powerhead

[toyvette81]

what do you guys think about the duncan powerhead for the 86 250r is it worth the 200$ or is it just as good to have headwork done to my stock head what i dont understand is it says works with ported cylinders..what the hell?! lol i guess they mean bored cylinders but anyways what do you think says they have 20% more cooling area and they bost compression a little bit.. it that all they do or is it a whole new head thats ported and polished and better thna the stock one worked to the max?

[Nightbiker07]

lol, i dont see how a 2 stroke head can be ported and polished.......maybe a cylinder, but not a head.

about the only gains a different head on a 2 stroke will gove is higher compression and better cooling.

[deathman53]

They do cool better, I had a cool head on mine. There was one problem that was one of the causes for getting rid of it for a stock shaved head, the spark plug comes straight out of the center. Its pretty tough to get the plug in there, esepecially on a 85 frame. On 86 frames its abit easier. Those cool heads, aka powerheads can make more power because of the different cc heads you can use, compression changes with them too.

[RideRed250R]

they state it works with ported cylinders because of the fact u can raise the compression for your application. if you believe that u will stay with a 250R jug for the rest of your bikes life then yah go get one, the ability to change domes per application is a cool deal, HOWEVER, i suggest just milling the stock one, cause who knows if you might go with a big bore cylinder and aftermarket head later??? I suggest the ESR head if you do get a cool head, its a very nice design and HUGE water passages.

[toyvette81]

lol im thinking of my 350x and r at the same time lol getting my words mixed up but thats cool, i dont know if im going to buy one or not, might just get the head shaved, 1 mile from me is a small airport that sells all grades of gas so thats not a problem for me. but one more thing if i just get the thin 89cr gasket it will up the compression some right but will i stil have to use race gas?
and im having trouble finding sites that sell a higher compression gasket for my 86r or do i have to just go to the dealer and order a 89 cr250r gasket? if i do that are there a few different thicknesses? thanks

[Kintore]

I agree with deathman on this one, the spark plug changing on my 265 Powervalve motor witht he coolhead on the 85 frame is TIGHT. But hey the removable domes is wicked as well, talk about some power lol

[deathman53]

When I ordered my 310pv, I had them make the head just like the stock head, because of how hard it was to get at it with a "normal" trx cool head. On a 86 frame its not as bad, still a pain. When I had my frame made, I had them make it so that this won't be a problem if I change motors.

[RideRed250R]

yah my 410 motor required me to... convince (with a hammer) my frame to except my spark plug.

[toyvette81]

what psi are they at stock? what will just a thinner gasket get me at? much difference at all?

[toyvette81]

how much does he charge

[toyvette81]

liquid darkness do you know what psi the 86r should be at stock?, and what the .020 will bring it to?
thanks

[NOS_350X]

The compression ALL DEPENDS ON elevation. Most stock R's will be around 160psi-175, ive never seen a stocker over that. More compression more bottom end power. Less compression more top end power, to put it in easy terms. So with any coolhead, you can change the domes from 22cc domes to 16cc domes. The porting on your engine will also affect the Psi numbers. As an engine builder anyone that is putting out more than 175 psi i recomend race gas. If they dont i wont warrenty it.

IMO the changeable domes, is well worth beaing able to tune your motor you want torque change it, you want hp change it. realy easy.

[toyvette81]

cool appreciate it