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800 Heads?

Posted: Sat Jan 06, 2007 6:58 pm
by ducinthebay
The newer 800ss motor has the same 88mm bore as the 750 (just stroked a bit). Apparently, they vastly improved the flow of those heads. Has anyone dropped a pair on a 750 motor? Does everything line up? Any tricks to get it to work? Does the 800 have an electronic tach, ie, no tack drive on the heads?

Just thinking out loud.

Posted: Sat Jan 06, 2007 7:43 pm
by jcslocum
Maybe, but for the cost and work involved, it would probably be easier to have the existing heads worked.

Posted: Sat Jan 06, 2007 9:21 pm
by persempre907
The old engines, like the Paso ones, have bigger valves than the last engines.
Now the engines use leaner mixture for the pollution reduction.
So, I don't think the newer heads might improve something.
Ciao

800 Heads?

Posted: Sat Jan 06, 2007 9:56 pm
by ducinthebay
I was mostly thinking of getting some used heads from a crashed bike, instead of buying new. Used heads can be had for pretty cheap (~$200) compared to some of the quoted porting jobs (~$2,000) that I have found so far. If you know of someone who will do a reasonable porting job for under $500, let me know.

Moto-One has a nice writeup comparing the engines from different years.
http://tinyurl.com/y3tcgn
It says that the 800 got the bigger valves from the 900, which the 750 didn't have before. 41/35 is now 43/38. The HP/Liter is also pretty high. Sounds enticing.

Can you adapt carbs onto the heads designed for fuel injection?

Re: 800 Heads?

Posted: Mon Jan 08, 2007 2:29 pm
by Desmo_Demon
ducinthebay wrote:Can you adapt carbs onto the heads designed for fuel injection?
A carb conversion shouldn't be any different than putting Mikunis or other carbs on a stock Pantah engine. I'm sure an early set of SS900 carbs would work, but you may have to fabricate some intake manifolds.

I have no idea if the heads would fit on the Pantah engine and would probably bet that you'd need to have the cases machined a little bit. I would doubt that the cylinder studs are the same spacings as the Pantah, so you'd probably need to run the newer cylinders and pistons, too. I have no idea of the interchangability of these engine componenets.

What may be a little easier would be an engine swap. There's been several discussions about running an SS900 engine in the Paso, and maybe a newer 800/1000 won't be much more difficult of a conversion.