New Non-KX Project

[umberto]

The piston:



The valves (that's my index finger):

[sandblaster]

That little scoot is gonna go...

[umberto]

I'm pretty excited to ride it.  Those little Honda's will really pull for such a small motor.  Of course I'll have to beat my 14 year old to it.  I think he's more excited about the little 50 than he was for his 05 KX 125.   

I've also lined up another project after I am done with this one.  Let's see if anyone can guess what it is.  It's a two stroke 50 that's a bit off the beaten path.  My dad used to haul home all kinds of bikes when I was young and bikes were cheaper and simpler.  I actually had one of these bikes, but mine is long gone.  This bike was purchased at the same time and from the same dealer, and is in pretty good shape.  It's a 77 or 78.  Any guesses?

[DoldGuy]

MR50?

[umberto]

Man, I wish. I had one of those too. This bike is a little smaller and more exotic...

[umberto]

Looks like I found the problem.  As I kind of thought, the valve seal on the exhaust valve rusted and was not sealing.  I found gas in the exhaust pipe, and rust under the valve in the head.



I got the new head and piston installed, the valves adjusted, and the cam timed.  The head studs did not feel right to me when I was tightening them (before torqueing).  I decided to order new ones, instead of breaking off one of the existing ones most likely in the block knowing my luck.  That's all I have left, so maybe next weekend I can post a ride video.  

[umberto]

I got all the parts in yesterday and finally reserved a bit of time in the garage to finish up the might Z50R.  I'll let my good friend Ace Ventura take it from here:



I got to ride it around in driveway for a few minutes and man did that bring back memories!  I have a small oil leak on the cam cover I need to address, but it's pretty minor.  I'll be checking the microfiche to see if I missed an o-ring or something.  Once I get that fixed I'll trick the boy into riding it around for a youtube video.  I look like a hippo when I ride it.   

[umberto]

I got the oil leak fixed, but mother nature decided to bring real winter to Oklahoma.  My stunt rider doesn't work in sub 50 degree weather.   

I'll try to post a ride video as soon as the white stuff is gone.

[umberto]

Ride videos as promised.  For such a small bike, this thing has a ton of torque.

https://www.youtube.com/watch?v=bxBmQ9-lbiI&feature=youtu.be

https://www.youtube.com/watch?v=RHNRuFtbR4o&feature=youtu.be

All that is left now is to install the tires and new tubes and paint the rims.

[sandblaster]

Sounds good

[umberto]

Thank you Sandblaster.  I was so relieved when it ran.  Even though I grew up working on cars, four stroke motorcycle engines scare me.  All those unnecessary parts and no expansion chamber.  

Oh, and for my next project I managed to find one of these.  Did anyone else have one as a kid?  It's an Italjet two stroke 50.  They were originally marketed as Indians in the early 70s.  I'll get some better pics up once I have it in the garage.

[81cr450]

WOW that is clean , especially for a kids bike. Fun looking project

[Brute]

How about the Honda RC166 if you want crazy small parts and lot's of them! 250cc, 6 cylinders, 24 valves. 41mm X 31mm bore and stroke. 20K RPM and 65 hp. Valves the size of tack heads. All designed and built by hand before the age of computers. Won 10 out of 10 races before they were done away with. One of my favorite motorcycles.

[LukeG]

I would love to get a NSR500 twin GP engine and stick it in CRF chassis. What a supermoto that would be!

[81cr450]

Brute made me curious, 7 speed trans in there



http://world.honda.com/MotoGP/history/RC166/