PlanetMinis Forums banner

1 - 20 of 30 Posts

·
Registered
Joined
·
27 Posts
Discussion Starter #1
I picked this 78 Z50 up from a friend, it’s rough but for the most part it’s all there. I stripped it down to the bare frame. It was missing the steering stop, I did some bartering with Kirrby for one and I welded it on.

I dropped the frame, swingarm,footpegs, and seatpan off to get prepped and powdercoated gloss black.

I got the top end off the motor, it looks like the timing chain was pretty loose and machined a groove in the cylinder. I gave the head a quick cleaning for now and may soda blast it before it’s assembled.

The rocker arms each have a faint line on them where they ride on the cam. One rocker you can just feel the line and the other one doesn’t catch my fingernail. Should they be replaced or are they good to reuse? Also, it appeared to be missing the washer that sits on top of the cap for the exhaust valve seal. It didn’t seem to ever have been opened up before so I’d imagine it left the factory that way, I think I have one of the washers in my used parts stash.
274706
274707
274708
274709
274710
274711
274712
 

·
Registered
Joined
·
1,272 Posts
You're gonna want to replace those rockers. The one MIGHT be ok for a while..? But the other has lived it's life. I'd just replace both, then you'll be glad you did once the money has been spent.
This is one of those parts that are hardened...but only skin deep. The part isn't hardened, all through. It only hardened on the outer surface. Once you wear thru the outer layer, it'll start to wear double fast.
I hate spending money on stuff like that...rocker arms...cam chains and rollers...drive chains and sprockets...They don't make you go any faster. They're easy to get to and replace at any time. But they're ALL part of a good job. Do it the best way the first time, and be done...well done.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #4
Thanks Kirrby - I’ll either grab a new OEM set of rockers or I’ll try the aftermarket ones that DRATV has. I did order a new cam chain and rollers already.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #5
It took the powdercoat shop about a week to get it done, turned out great and was very reasonable. Only issue I see so far is that he didn’t mask off the rear brake lever post like I asked. I do plan to chase all the threads, it looks like he plugged most of them before applying the powder.

This is about the 5th bike I’ve restored but the first time I have had anything powdercoated. I’m impressed that there is almost zero orange peel.

For ground purposes will I need to clean off powder around the area on the frame where the engine mounts?

274720
274721
274722
274723
274724
 

·
Registered
Joined
·
27 Posts
Discussion Starter #8
Looks really good! You can just file out the inside of the engine mounting holes to get a good ground.
Thanks for the information. Is it also necessary to do the same for the holes where the ignition coil mounts?
 

·
Registered
Joined
·
27 Posts
Discussion Starter #10 (Edited)
I briefly worked on the bike. I was able to get the new races installed for the steering bearings. The races went in fairly smooth, the bottom race bottomed out further into the steering neck then the upper race did.

I used some fine valve lapping compound and lapped in the new valves fairly lightly. I filled the combustion area of the head with WD-40 after the valves were lapped but they didn’t have the springs installed. After half an hour they didn’t leak so I called that a success. I want to soda blaster head before I do a final assembly.

The valve seats have a few small areas that look like pitting in the photos but just are some dark discolored spots.

Does anyone know where to get replacement seat foam? I looked around quickly and there was some on eBay but with shipping it was around $60. For another $10 I can get a complete seat from CHP. I’d like to reuse my stock seat pan but if I can’t find a better price on the seat foam I may have to get the CHP one.

Also, the tag on the steering neck is in rough shape. I saw on eBay there are replacements. Anyone know any other suppliers for the tags? I want one that is aluminum like the OEM ones and not the sticker kind.
274739
274749
274741
274742
274743
274744
 

·
Registered
Joined
·
27 Posts
Discussion Starter #11
Last bit of progress for the week.

I got the tires separated from the rims. I use a oscillating tool to cut the tire around the rim and them cut the strip off the rim that’s left, make quick work of it.

The front rims are a little more rusty then the rears were but overall should be fine. I think I may try VHT caliper paint this time and see if it’s close to Cloud Silver. I’m also open to suggestions.

I got the stator plate off to get a peek inside. The two screws holding the plate on didn’t budge with the manual impact driver and stripped. I drilled them out and two screws in the engine case that didn’t break free. I should be able to get the cases split in the next week or two.

I did see a little surface rust/slime on a few of the timing components. It seemed to wipe off fairly well, worst case I’ll soak it in some Metal Rescue that I have on hand to clean them up.
274752

274753
 

·
Registered
Joined
·
27 Posts
Discussion Starter #12
I bought a new Honda stator cover from a major retailer. I was a little disappointed when I opened the packaging and took it out. Looks like it was poorly machined on the edge. It’s not the retailers fault, poor quality control on Honda’s end. I’m not sure the retailer would accept it as a return since I opened it.

274777
274778
 

·
Registered
Joined
·
165 Posts
I got a new one as well and it had small flaws as well. Build is coming along very well, powder coat looks great.

What was your technique for getting the swing arm bushings out?
 

·
Registered
Joined
·
27 Posts
Discussion Starter #14
I got a new one as well and it had small flaws as well. Build is coming along very well, powder coat looks great.

What was your technique for getting the swing arm bushings out?
Thanks for letting me know, it’s probably not worth the effort to get it exchanged then.

I removed the swingarm bushings using a vise and two sockets. I pushed the bushing out using a 12mm 1/2” drive socket, I had the drive side of the socket against the bushing and pushed it into the larger impact socket. It took me less then a minute per side. I need to freeze the new bushings before I attempt to press them in using the same method.

274780
 

·
Registered
Joined
·
165 Posts
Thanks for sharing your technique. I have a swing arm I need to pull the bushings on and have powder coated. i got the upgraded bearing type bushings for it From All Balls.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #16
I could be wrong but I think the All Balls kit maybe easier to install then the OEM style.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #17
I made a soda blaster using 3/8” ID tubing, a plastic cup and lid from a convenience store, and a air blow gun. It worked pretty well and it cleaned the head in about 5 minutes using 3LB of baking soda for a total of $2.40.

I rinsed the head in hot water after, then heated it with a heat gun to dry it, and lastly put oil on the valve guides and combustion chamber. Looking back I’d skip the wheel cleaner next time and go straight to the baking soda.
274784
274785
274786
274787
274788
 

·
Registered
Joined
·
27 Posts
Discussion Starter #20
The baking soda dissolved in the hot water rinse/soak from what I could tell. I blew it out air and I didn’t see any residue left behind.
 
1 - 20 of 30 Posts
Top