Katit's 1978 KZ650 project

Looks great, don’t forget the trans bearing lock rings. Number 5 on the fishe.

 

Yesterday evening spent assembling bottom end. Checked transmission, all sizes well within specs, close to new. Main chain has about 20-23mm play, service is 27. Great because I didn't want to buy it
Anyhow, another $300 spent ordering little bits and pieces.

Don't know why, maybe my engine was built on Friday night but I am seeing more missing stuff. Lock washer under bolts on kickstart stop missing. It wasn't there from beginning..

Next step is to get carbs sorted and once I have carbs apart and checked - do plating on all hardware. By the time parts come in I should be ready for reassembly with everything.


 

Making some progress. All hardware to plate sorted and ready. Carbs being evaluated. In very poor dirty shape. Lot's of dirt in bowls.
I got new plastic barrels (for enrichment), new o-rings (viton kit). Some new hardware. Reusing jets and other stuff.

Going to soda blast bodies and then ultrasonic clean everything.

Questions:
1. Is there "bad" carb gaskets? Kits on ebay for $10 which sell 4 top and 4 bottom will work? Shouldn't be big deal I think but still..
2. Any good source for those rubber cups/seals under plastic barrel? I assume it's good idea to replace them as well
3. Should I up main jet size? I am using stock airbox with 4-1 Delkevic exhaust. If so, what size and where to get? Elevation here 500 feet.




 

For carb kits I would go with Keyster.  Except I would not use their choke plungers because they don't have the point on the end.

Those rubbers and the plastic risers above them are available on ebay from several suppliers.  I've bought them from retro-motorcycles.  The entire assembly is also used on most of the big Mikuni carbs.

Rewinding a couple of pages but what did you decide regarding the head?  Going to have a local shop do the work?  
Regarding the valves, since the seats are getting cuts you need to tip the valves to bring them into the proper factory range.  Don't worry about what the manual says, you can tip the valves a good amount before running into problems.  Key thing is to make sure the keepers don't stick up above the valve stem after everything is installed.

Regarding the carb gaskets, I recommend staying away from the hildebrandtgasketcompany  gasket guy on ebay.  Their gaskets are made from really thin material.

wrote:

Rewinding a couple of pages but what did you decide regarding the head?  Going to have a local shop do the work?  
Regarding the valves, since the seats are getting cuts you need to tip the valves to bring them into the proper factory range.  Don't worry about what the manual says, you can tip the valves a good amount before running into problems.  Key thing is to make sure the keepers don't stick up above the valve stem after everything is installed.

Regarding the carb gaskets, I recommend staying away from the hildebrandtgasketcompany  gasket guy on ebay.  Their gaskets are made from really thin material.

Ed, yes. Head is at local shop for a week now. Just gave them a call, their guy was sick, they will look at it next week. I didn't bring whole thing (cams/caps/shims) thinking they will just do valve seats. Now that I think about it - you are right, I will let them do whole thing. Will drop rest of the parts on monday and have them do gaps as well. They guy is knowledgeable, have to trust. He was surprised I didn't bring whole thing because "they do it all and set gaps for shims I have"

For the gaskets - any other suggestions? I did order from this exact guy you mentioned..

Bunch of parts waiting for plating. Hopefully will get to it this weekend, my first time using Caswell kit..


 

Took carbs apart. They all missing #39 "limiters". I understand those are not required. 
Because previous "mechanics" got in there, I had to check needles. They all seem to be set stock (second slot from bottom) but thin washer over one needle was installed ipside down. Tiny "dimple" need to point down from what I understand.

For rebuilding - I am going to go with Ed's advice. No metal parts will be replaced. All jets etc seem to be perfectly fine. Hard to read numbers though.

Any advice on assembly lube for linkages and moving shafts? Silicone grease?
Any advice on where to get replacement drain tube in bulk?
Supply tube?
Those little sections (vent pipes) between carbs?

After seeing inside - a lot of crud, one carb had idle passage completely blocked with some white chalk (on picture)

My plan for cleaning/rebuild:
1. Soda blast cases and covers.
2. Ultrasonic clean all metal parts in Simple green solution
3. Blow and check all passages
4. Zinc plate some parts, some top screws replaced with original.
5. All rubber replaced except for shaft seals (go through all carbs) - those look good and it's just dust seals. Also, starter plunger has sealing rubber in them, I will leave those be.
6. Bench sync
7. Check and set fuel level

 

I’d strongly suggest two things with the carbs. 1) keep the Float needle and seat paired up as a set, polish them with good brand Q-tips chucked in a drill at low speed. I’ve have good success with Mothers Aluminum polish. I carefully chuck the needle in the drill and polish up the needle tip with soapy water and 2000 grit wet sand.  2) save yourself some tuning issues later and have zed1015 replace the seals in the choke plungers.

also make sure to free up the spring loaded tip in the float needle. 


 

 

wrote:

I’d strongly suggest two things with the carbs. 1) keep the Float needle and seat paired up as a set, polish them with good brand Q-tips chucked in a drill at low speed. I’ve have good success with Mothers Aluminum polish. I carefully chuck the needle in the drill and polish up the needle tip with soapy water and 2000 grit wet sand.  2) save yourself some tuning issues later and have zed1015 replace the seals in the choke plungers.

also make sure to free up the spring loaded tip in the float needle. 


 

Great advice. For #1 - I do keep all internals/small bits/and slides sorted by carb number (with body). Covers - just going to put whenever, they all the same. 

For #2 - How? Mail it? Thats the only pieces will be left with old worn rubber and I sure do want it refreshed

wrote:

wrote:

have zed1015 replace the seals in the choke plungers.





 

For #2 - How? Mail it? Thats the only pieces will be left with old worn rubber and I sure do want it refreshed

Yes! The old plunger seats will be hard ,leaking and are not ethanol resistant.
I can fit new Ethanol resistant Viton seats to your original plungers .
I'm in the UK and you need to mail them but it only takes a week or so for the return trip.
I have done many world wide and all have good results.
PM me for details.

I have brain fart. Please help. I am going to take shims, cams, caps to the shop so they do full valve job and cut valves to my shims. I have spare engine so I have 16 shims. I split them into "large" and "small" groups. It makes sense to give shop large shims, correct? This way they will get it setup for bigger shims and when/if I need to adjust I will adjust using smaller ones. Correct?

wrote:

I have brain fart. Please help. I am going to take shims, cams, caps to the shop so they do full valve job and cut valves to my shims. I have spare engine so I have 16 shims. I split them into "large" and "small" groups. It makes sense to give shop large shims, correct? This way they will get it setup for bigger shims and when/if I need to adjust I will adjust using smaller ones. Correct?

Yes! You want the thickest shims possible to maintain room for adjustment.
Make sure the shop knows what they are doing as re-cutting seats and re-facing valves reduces the clearance.
Material can be taken from the valve stem tip to reclaim lost clearance if you end up on a thin shim but there's a limit to what you can do with the shim under bucket set up.