TOPIC:

This is a continuation of my other thread in the engine forum for this $175 1982 kz550 LTD. Long story short PO said the bike was running, but when i fixed all the hidden issues preventing it from starting i found some pretty bad knocking. Thought it was from the head/timing but it turned out to be rod knock and the bearing seized the engine while attempting to figure it out.

I picked up a kz650 motor from a 1979 z650 C3 for $150 at a swap meet rather than trying to deal with some shop in ohio through ebay for a crank so I'm currently fitting that in the frame.

Here's how she sits now:

All stock solids mounts were removed besides the lower front mounts, which were trimmed a bit to fit the wider block. The lower fronts are still off too much and using them would run the rear of the engine into the swing arm. . But besides being tilted forward a bit the engine fits well and the sprocket is exactly where it needs to be.

Now I need to pick up some 1/8in plate and bolt sleeves to make the new mounts.

Cool.. Is there enough clearance to the frame to get the cam cover out and in for future valve clearance checks?

I also wonder about installing a 750 block with an 810 kit

Will the 6 speed tranny fit in that?
Steve

At first the valve cover did not fit but that's before i cut out the old mounts. It was really close before (only needed like 1/4in of clearance) so we should be good to go now.

Maybe one day if i find a 750 ill swap it but for now this is good enough.

Yes I could swap the 6 speed from the 550 motor but i think for now i'm just going to focus on getting it running.... Speaking of which.... The 650 was missing the clutch rod and the 550 one is slightly larger in diameter. Anyone have the dimensions for the 650 clutch rods?

Better check the oil level before trying to start this engine......

Can't wait to see how this turns out

Lol yea that be bad! I have some non moly 10w-40 for it.

Managed to get the engine in the frame with the valve cover on! It has to be done in a very particular way and unfortunately the valve cover probably wont slide out underneath the main hoop with the engine in the frame. I'll have to check again.



I got the rear upper mounts sorted. Just reused the stock mounting plates with new holes drilled. Ill need to go back and weld the old ones shut. The stock left side spacer bushing can be reused on the top mount which was super handy for verifying my sprocket alignment.



I also found that moving the engine forward a bit and rotating it backwards makes it sit quite a bit better,



Lastly, I got these carb spacers drawn up in SolidWorks (the 550 carbs have a different spacing). The plan is to get them 3d printed and then soak them in epoxy to make them air tight. The goal here is cheap so no 300+ carbs for me!

So, you will have to remove the engine to check valve clearance?

I am not sure about epoxy on the carb holders. The rubber needs to be soft in order to seal against the head and around the carbs.

Maybe. I haven't tried getting the cover out with the new engine position. The main problems are the exhaust studs and the rear lower mounts on the crank case. The engine is simply too long to sit down all the way. I may be able to tie the cover to the upper frame bar and sneak my feeler gauges in. Ill look into this situation further.

Oh yeah, I forgot, i will be using short sections of rubber hose to connect the carbs to the holders. I always use a bit of rtv to seal the carb holders to the head otherwise I always seem to get leaks.

oooooh shit, hold onto your seats!


Parts!


Carb boots. Printed in ABS and then coated in thinned down epoxy.


Bought some new old stock 7mm plugs for some random car. High quality. Cheap. Just snip one end and put on the old connectors.


left side of the engine


Right side.


Carbs mounted. 550 carbs on 650 so the goal here is to turn in the idle screws and just get it running.


Heres a quick overview of the mounts:
Upper front right: reused old mounting plate with new hole drilled. had to space it out a bit due to the wider engine.
Upper front left: cut old mount, drilled frame, welded in new bushings, and made new bracket.
Upper rear mounts: drilled new holes in previous brackets.
Lower front: cut out and trim, reweld in proper place.
Lower rear left: cut off tab, trim tab to fit, reweld
Lower rear right: cut off tab. made removable plate mount with spacer.

I started by trimming the inner sides of the front lower mounts so the engine would sit center. The rear upper left mount can be used with the old 550 spacer to align the rear of the motor. this lines the chain up perfectly as well.


So! should be starting it tomorrow!

I got it running! kicking it was a pain but it turned over eventually.

There was some goofy stuff going on with the oil light (I know i had pressure because it was coming out of the clutch rod hole) but that turned out to be atleast partly a missing ground. I say partly because i couldnt get any reading from the sensor with a multi meter. The 650 sensor was closed (~1ohm of resistance) with no pressure and open (Megaohms +++) with pressure like i expect a oil pressure switch to act. However the 550 switch has no resistance measurement at any state. Is this normal? do the 550 switches work differently or is the 550 switch bad?

Next thing to deal with is the clutch rod. The 550 has a 8.05mm bushing with a 7.95mm rod. The 650 has a 7.05 bushing with what i'm guessing should be a 6.95mm rod (as i don't have this clutch rod). I don't know if the clutch rod bushing (which is visible with the gear plate taken off) is removable without splitting the case. If it is, i can swap that to the 650 and use the stock 550 rod. Otherwise i can just throw the 550 rod in a lathe. Also, since the 550 transmission can go in the 650, the rod lengths should be the same....?

Thoughts on these oil and clutch rod situations?


Video photos.app.goo.gl/na71d47b1vpQEhgv2 I had to trim the exhaust because it was touching the oil pan. The two inner runners also had to be bashed in to clear the frame.

Edit: i checked the oil sensors again and now they both measure out properly on the multimeter. I don't know whats up but i left the 650 one in.