Topic: Big bore build, advice?

[Red750K1]

Ok, thinking about using the cycleXchange 850cc big bore kit on my '71, BUT don't really want to mess with the originality. Thinking about 2 paths:
1:  Use one of my rebuildable "extra" motors and go nuts, rebuild, 850cc, nice cam, ported head yada yada, toss it in and put my original motor in the basement for a "nap".  Only down side I see to this is I know the motor in my '71 is good, the trans is perfect and I've had no problems with it since its own rebuild (just rings/gaskets/seals).
2: Use my motor but get an extra head and jugs (donor motor or bone yard) and have those jugs punched out and port that head. Should proally have the surfaces decked to true them up. This way I know my trans is good and I can just stick my original head/jugs in the basement. The only down side to this I see is if something goes "boom" then my original motor is toast.

I know that cyclexchange offers a "core for a bore" deal where you trade in a good core set of jugs and they exchange for a set of bored jugs. This makes me think I should be able to use another set of jugs with no problem.

Also, has oneone else used the 850cc kit? I know its alot cheaper than the 836 from weisco but is the extra money worth the forged weisco pistons vs the cast 850 pistons? Hmmm . . . anybody do this? any dyno or 1/4 mile numbers? Ok everyone, shout back, and yes I can set my floats inside joke never mind.

[754]

How hard do you plan on running it? Do you plan to race it?

Having an 836 or + with a cam, may change your riding style..

[Red750K1]

I want to have a nice spirited daily driver. I'm more concerned with reliability than speed. I'm even thinking about building a motor, use it for a while then go back to stock and stick the hot motor in a cafe build to sell or possibly race.

[mystic_1]

I want to have a nice spirited daily driver. I'm more concerned with reliability than speed. I'm even thinking about building a motor, use it for a while then go back to stock and stick the hot motor in a cafe build to sell or possibly race.

That's more or less the position I'm in now, rebuilding my K0 and I've decided to stay mostly stock with some mild tweaks and improvements.  Once I'm done I will use my spares to put together a hotter motor for a cafe project to satisfy my adrenalin cravings.

mystic_1

[Sam Green Racing]

The 836 Wiseco pistons allow you to run tighter tolerances.
With a middle of the road cam, porting, decent carbs, pipe and ignition you will see performance increased through out the rev range.
Our motor made 86bhp with 62ftlb of torque and runs 12 seconds through the quarter mile.
Allthough the bike is not used on the road, It certainly could be.
The only draw back with these big motors is, they get hot very quickly and a good oil cooler is essential.
Contact Mike Rieck for your head work if you want the best, also do a search for Sparty's motor build to see Mikes motor building prowess.

Sam.