Project Cafe Rocket 686 begins. Finally!

[edfmaniac]

I don't think decking the head will reduce the squish. It will increase comp ratio and decrease clearance between the valves and piston, but it won't reduce the distance between the top of the piston and the deck. You'll have to add or remove gaskets from the cylinder base to do that. And we are talking a few thousandths of an inch so you won't have to worry about the length of the cam chain or position of the rocker box cover/top motor mount if that is what you were talking about.

P.S. The head gasket comes into play as well. Compare the thickness of the gasket you use to check the squish with the one you are going to do final assembly and make adjustments accordingly. I ended up adding one extra fiber gasket at the cylinder base to get enough clearance. Bill J. said you need a 1mm min. clearance.

[Srinath]

I'm not talking about the CR or squish volume etc ...

If we took some material out of the underside of the head, like when we mill it etc ... the top frame mount will stop fitting right.
I believe mine has been decked before I got it, and that's why my top engine mount on top of the valve cover - one of the ears broke off before I got to it even.

Cool.
Srinath.

[edfmaniac]

Good luck with your build. I don't think we are communicating well enough for my input to help you any.

[edfmaniac]

After spending more than 3 weeks in route, my carbs finally arrived in the US and are headed my way. It's been a frustrating couple of weeks trying to figure out where they were but they are finally on the move again. Hoping to be running by the weekend if Topham did a good enough job on guessing jet sizes.

[edfmaniac]

It's here. Probably going to take a day or two to get everything in line as far as final mounting, cabling, and air filters.

[phoenix76rb]

Can't wait to see how it works; looking forward to your next installment!

[edfmaniac]

The left side carb boot needed some more Dremel tool work because the minimum spacing on these carbs is 70mm and the center to center spacing on the stock boots are 65mm. Also the diameter on the boot was a little on the small side so I enlarged the ID and did all my work so that the new center would move as far to the left as possible. Cables were completely compatible, just a little long. Use the extra slot that is provided on the throttle pulley to take up as much cable as possible. Filters are on order and I discovered that the petcock on the tank I'm using was right where the throttle pulley is so I had to cut off the valve part of the petcock, add a brass tube in it's place and install an inline fuel valve. Once I determined that the bowls weren't leaking after turning on the fuel, I decided to fire her up. So far so good. Idle is solid as a rock. We get to see how she does out on the road in the next few days. Can't wait to see if these solve my problems above 7500rpm.

[sanddune51]

Any news yet?

I'm sure you have it up and running but just spend every waking hour out riding it ..... with a huge grin .


Mark.

[edfmaniac]

I was on my way to pick up my UNI filters when some jackass blew his red light about a full 15 sec after it turned red. I could be really upset that I just rebuilt everything from the pressure plate on the back of the perfectly running straight 6 all the way back to the rear u-joint, but I walked away with only bruises and scratches. So no, I haven't ridden the MZ yet. Too damn sore.

[edfmaniac]

My friend thinks it looks like one of those characters from Cars, the Pixar movie.

[DAVID THOMPSON]

good thing you were in the truck
dave

[sanddune51]

I'm sorry to hear of your accident, but happy that you'll live to fight another day.

Get well soon.


Mark.

[Srinath]

Oh jeez that looks horrible.
Its a good advertisement for those 70's metal monsters tho.

Drunk driver running the red ?
Crackhead ?

Cool.
Srinath.

[edfmaniac]

I would put my money on cell phone texting. He was young and appeared to be sober.

[edfmaniac]

Mikunis are in and running good. I was expecting to notice a distinct increase in acceleration on the top. But instead, the power is very linear. There is much more bottom and mid range so the top end charge doesn't stand out anymore. It's just strong everywhere with instantaneous response. Next step is to order a few main jets and head to the dyno.