"I got it one piece at a time..." (rebuild)

Thanks to all who are helping me with my sand problem. I'd like to do a rebuild on the cheap using parts from three different engines. Please feel free to provide input, criticism or advice. This is the first time I've had an engine open with the intention of having it run again.

Forgive me if this sounds like a Johnny Cash song.

Here's where I'm at with the project:

Bike 1 engine in frame.
XJ 650 Maxim
- Lower case (with a bit sand in it) is in good condition. No gear grind, no starter chain guide grind, etc.
- Cylinder assembly is free of scoring.
- Had bad compression and no power.
- Cylinder head looks like hell, with lots of charred bits and nasty black stuff. (removed)
- Cylinders have lots of carbon buildup. (will remove)

Bike 2
XJ 650 Maxim #2
- Had bad compression before it was removed from the bike.
- Second gear gone.
- All covers removed (sitting in heated antifreeze in an effort to polish the aluminum.)
- Has no shims.

Bike 3 (completely intact engine)
XJ 650RJC
- Gears are pooched.
- Cylinders had good compression before the bottom end went.
- On the cylinder head The bolt helicoiled into the #4 intake manifold has been re-tapped twice. Don't want to tap it a third time.
- Engine is removed from bike and still assembled.

So here's my proposal. Tell me if you think this might work.

Take lower case from Bike 1. (Maxim) (First washing out the ten grains of sand that fell in there and inspecting the pump)
Add cylinders from Bike 3 (Seca)
Replace O-rings with new ones
Re-hone cylinder assembly from Bike 3 (Seca)
Tidy up cylinder head from Bike 2 (Maxim) with wire brush.
Add valves and shims from Bike 3 (Seca)
Add cam shafts from Bike 3 (Seca)
Do valve adjustment using NEW shims (I've read chacal's warning on another post).

P.s. In case you're curious why such a newbie has three engines lying around. I buy dead XJ bikes for $100 or less and use them for parts on several running bikes. There are enough dead ones lying around that I figure I can make one that works.

THANKS!!!

 

I can't help you too much with the Frankenstein project, other than saying it looks like a lot of work, and is something I would probably try. I do wonder why you would want to use the top end from Bike @ if the Seca had good compression in the first place. I would keep all of its related parts together, and just use the parts from Bike 1 to fix the trans. Helicoil it the right way, and you are done.


But on a somewhat unrelated note, do you have any other parts from that Seca still around? I'm looking for spares for my '82.

 

Will look into the helicoil. That might not be a bad idea.

Will contact you directly regarding parts.

 

what's up with this ?

 

Regarding antifreeze, I just posted this:
Cheap aluminum CLEANING
http://www.xjbikes.com/Forums/viewtopic ... tml#181904

 

Only snag that I can see is in swapping-over the Valves.

You'll have to Lap the Faces and Seats when you install Valves from another Head.
After you Lap the Valves, ... check the Head for leaks before putting it back on.
With the Seals and Springs reinstalled, and Spark Plug in, ... level the Head with the mating surface and combustion chambers facing up.

Fill the Combustion Chambers with fuel.
Look for bubbles or the level leaking down to indicate the Valves not gas tight.
On those that leak after Lapping the Seat and Valve will need to be refaced with the Cutting Tools.

 

Rick (or anyone), do you think, as Cooter suggested, that I might be better off using the Seca cylinders, assembly, head, valves, and cams? Should I just deal with the Heli-Coil?

 

With the situation being to save some time and money and get a good runner, ...

Stripped-out Intake Manifold Threads are an easy fix.
A properly installed Heli-Coil will handle the Torque load on a Manifold Bolt.

If the Engine is out or the Head is off, ... you also have the option to have the stripped-out threaded holed welded and re-tapped.

I've seen it done two ways.
Enlarge the hole and fill it with new material.
Grind-off a chunk of the lobe and rebuild it up with weld material.

In either case ... have a Brand New Gasket to use as a Template for getting the Holes right.

Here's the address of "The Heli-Coil Guy" at Black and Decker.

Emhart Teknologies
A Div of Black and Decker
Industrial Division
50 Shelton Technology Center
P.O. Box 859
Shelton, CT 06484 USA

Tel. 203-924-9341
Fax. 203-925-3109

Email: emhart.teknologies@bdk.com