I couldn't find the heads listed, I saw them last week, perhaps they have been sold...also my FB account is hosed up again. If somebody still has this guys info I'd sure like to see if they are still around.
I'm not really sure if the 81 head is worth investing in. With the goofy built in injector mount, it's unclear how that effects flow. I once saw a description or info on the different type KZ/GPZ heads and their flow abilities from some race shop, however I have not been able to locate it again. Ultimately my goal is a poor mans version of a S1, minus the crank flipping and magneto's. 120HP at the wheel, at sea level correction would be plenty for me with this bike.
From what I'm reading all of the larger cams require clearancing (???), and the 81-2/J uses 17mm wrist pins, so there is a problem with using the bathtub heads (83/84) pistons due to them being 18mm? Or is there a 17mm version of the twin swirel/BT head pistons for the 81/J model engine?
Is the 83/84 crank a solid forged crank, or a pressed crank?
So far I THINK this is the formula I'm going to try, that I know will at least work. Keep my 81' head (me doing the port and polish), .410 (or.383) cam, upgrade the valve springs per APE, Ti retainers, degree the cams, bore the cylinders over to square them 1138 or larger, at least 10.25 CR, keep my Mic RS34 carbs, keep my 4into1 original Kerker, install my Dynatek 2000 ignition. I'm hoping this is enough. If it's not, then I'll search out a BT head. What I found out from smarter people than me; the BT/TwinSwirl head makes more power manly due to larger valves and ports maybe also better squish/combustion(not sure about the last one).
Still many questions floating around in my wee brain though!!!....
577nitro-
I don't know the seller but it looks like he has a few bathtub heads:
www.facebook.com/marketplace/item/175319...95-85d1-72e49940acda
I like this high-compression piston kit (1,135cc), over all others I've seen. Change epay, to ebay in the link below:
www.epay.com/itm/292948393891?hash=item4...3:g:sHoAAOSwdGZcWVUe
Just post the correct link, doesn't matter if its not a live link, it can be copy and pasted into any browser, that link you posted is to a Chinese money payment site...., the links useless...