OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Freakshow on January 29, 2008, 11:13:23 pm

Title: Dt1 heads 68-71 same as Dt1 heads 72 ?
Post by: Freakshow on January 29, 2008, 11:13:23 pm
are Dt1 heads 68-71 same as Dt1 heads 72 ? not the 2mx, just the DT1F

they all look the same to me, so why do folk list them as pre 71 only ? surely the are the same fitmanet and squishes or are the pre 71 units piston port and have different cones ?
Title: Re: Dt1 heads 68-71 same as Dt1 heads 72 ?
Post by: firko on January 30, 2008, 09:37:38 am
The early DT1 heads and the later heads have different spark plug placement and combustion chamber volume. Perhaps they want the earlier heads to be legal in pre 70. I don't know which is better as I've never run a stock head.
Title: Re: Dt1 heads 68-71 same as Dt1 heads 72 ?
Post by: Nathan S on January 30, 2008, 12:27:03 pm
Dunno how it applies to a DT1/DT2, but an AT2 (reed valve) head on an AT1 (piston port) gives you too much compression and it pings like a mofo after about 5~10 minutes.

I believe that the same is true for the CT1/CT2 - so my assumption is that it's also the same for the DT1/DT2.
Title: Re: Dt1 heads 68-71 same as Dt1 heads 72 ?
Post by: Freakshow on January 30, 2008, 02:06:48 pm
but a say dt1 reed would be ok on the piston port ? less or same comp and cc ?

Title: Re: Dt1 heads 68-71 same as Dt1 heads 72 ?
Post by: Freakshow on January 30, 2008, 02:09:18 pm
well i looking at weather this unit would suit my DT1F flat track project and i got confused when he dropped the word, 68-71  they seem to be the same to me ?

just wanted to save the $100 if it wasnt going to fit up.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=290201417127&ssPageName=ADME:X:RTQ:MOTORS:1123
Title: Re: Dt1 heads 68-71 same as Dt1 heads 72 ?
Post by: vandy010 on January 30, 2008, 02:20:57 pm
if ya can get it for a good price freaky,
BUY IT!
if it don't work you should be able to onsell a webco with no drama's
to me, it looks the goods...
Title: Re: Dt1 heads 68-71 same as Dt1 heads 72 ?
Post by: Freakshow on January 30, 2008, 02:44:36 pm
soz.... didnt get a positive response before item ended. always another one out there. :O)

but some feedback would be good so we have the heads up early on the compatibilty, and thus be informed on the differances, if any.