Topic: Maui Z1 1973

[MauiK3]

I’ll check the motor data plate to see if it can be switched. Good idea.

[MauiK3]

I made a blast cabinet from the cardboard box the compressor came in. It was very crude but for a first attempt it did what I wanted it to do and that is limit (somewhat) the loss and spread of glass beads. I started with a little hopper gun which was terrible. It worked but it was too bulky for the box. My siphon gun arrived which worked much better. I had installed gloves in the box but they were way too hard to use, I abandoned them. I learned from this that had I purchased a blast cabinet It would have been too small, it takes a pretty good size box to wrestle the engine parts around. Good learning experience. I achieved what I feel is a paintable surface which is what a 73 needs. Had it been a 74 I would have needed more aggressive media to get a nice clean bare alloy surface. The head was by far the hardest part with the deep fins. The glass gets everywhere. Just for fun I’m going to try some baking soda to compare. The compressor was fine, I had to let it catch up every 10 minutes or so but I also needed a break to to reposition and scoop up beads. My filter drier seems to work well. Had I wanted a bigger compressor the price really goes up between 30 gallons and 60 gallons, and I don’t have room for one. All in all, a sweaty, hard work success. Now for the intensive clean up.

[MauiK3]

I used about 15 pounds of glass, a lot of which I’ll strain and reclaim.

[MauiK3]

Thank you to my beautiful bride of 42 years for the use of the garden shed.

[grcamna2]

Steve,I see the quality of your work on the cases and top-end parts:they look Good 
I never would have considered building my own cabinet,but it makes good sense 

[RAFster122s]

Steve, you can always fabricate your own blast cabinet, if you are using dry media, from wood. Scale up your cardboard prototype until you find a size that can work...then go a little bigger.

Would you be able to store the compressor somewhere else and then wheel it up, connect with large diameter hose to your blast cabinet... Put together a weatherproof cover for your blast cabinet and store it outside? Put the blast cabinet on heavy casters or ability to throw a set of inflatable tires like for a cart or wagon to move the blast cabinet?
Just would need to setup a blind to make things more visually acceptable to hide it behind...
A wall of plants it would be hid behind when not in use...
Just some unconventional thoughts on the matter.

[Terry in Australia]

Good job Steve, I always say that "desperation is the mother (fcuker) of invention", and you've shown how you can get around a problem with some "thinking outside of the box" so well done mate, good job, and your engine will look great.

[MauiK3]

Thanks all, thinking about this for a bit as I move forward with the bike.
I'm leaning toward dry assembling it with no internals and painting it rather than wrestling with a full engine. I would likely have some nicks to touch up later but that shouldn't be too hard.

[grcamna2]

Thanks all, thinking about this for a bit as I move forward with the bike.
I'm leaning toward dry assembling it with no internals and painting it rather than wrestling with a full engine. I would likely have some nicks to touch up later but that shouldn't be too hard.

You plan on using semi-gloss engine paint which requires it to be oven-cured?
I hope your wife is patient with your choice of oven.. Lol 

[Terry in Australia]

Ha ha, Steve will probably build his own custom oven next Bill!

[MauiK3]

As I recall, Duplicolor high temp semi gloss or satin (have to check) black engine paint is one of the “correct” choices. And I’ll be baking it some in our oven since I don’t have anywhere else.
I’m starting to un-blank the cases and I’m happy that there is very little glass intrusion inside. I found a small amount near the starter mount hole. Of course I’m going to clean like it was full of glass but I’m more confident now that I won’t have any major amounts to deal with. That stuff gets everywhere!
I may build a wood box I can break down and store for the odd blast job that may pop up. It has to be larger with easy to use gloves, I’d want a 90 degree swivel on the air fitting, a view window/door that holds itself open, or a side door. 1/4” ply would be enough with a little hopper in the bottom to return the media back to a bucket.
My spokes are here, I can build wheels. Just like I thought, I have lots of work to do now. No hurry, we have a long riding season.

[Terry in Australia]

Yeah mate, give those cases a good wash with soapy water and plenty of water pressure to flush out all the oilways, regardless of whether you plugged them or not, then degrease with acetone before the paint.

Because you blocked all your threaded holes I presume that there was grease and corrosion in some of them, plus all the gasket surfaces need to be cleaned back to bare metal. Lots of work before you start spraying paint.

[MauiK3]

Sure thing. I ran a tap into the threaded holes but I have a lot of cleaning to do. I did the first phase yesterday, dip and soak in some Simple Green, garden hose flush through oil passages and down all the holes. Much more to do. My clear plastic bin will let me see what settles to the bottom of the Simple Green.
I'll be using Brake Clean to final flush out the threaded holes as well as a lot of acetone to clean everything up.

[MauiK3]

Yikes, I'm re-chroming 8 parts.
It's taken some time to find a shop that will respond to my requests, tried 3 shops, not sure why, Covid?
The 8 parts are: Brake pedal, brake reaction arm, brake actuator arm, kick starter (2 pcs), shift lever, fork ears.
The estimate is crowding $1000 by the time the haz mat fee is added, plus shipping two ways to California and back, of course.
It takes what it takes I suppose.
The Oahu shop no longer exists.

[grcamna2]

Sure thing. I ran a tap into the threaded holes but I have a lot of cleaning to do. I did the first phase yesterday, dip and soak in some Simple Green, garden hose flush through oil passages and down all the holes. Much more to do. My clear plastic bin will let me see what settles to the bottom of the Simple Green.
I'll be using Brake Clean to final flush out the threaded holes as well as a lot of acetone to clean everything up.

The inner passages are the most important,but an added benefit to all that washing will be your engine paint will adhere to the base very strong 

[MauiK3]

So I’m checking the valves out. The guides and valves were done in 2009 and I’m sure there wasn’t much wear since then. The exhaust seem fine but the intakes seem loose. I just ordered a small bore gauge to get an accurate measurement but in the mean time I used the dial indicator method in the shop manual. The exhausts come out at the top of the service limit using that method. I’m not too sure that’s accurate but they also feel loose. I’m going to coat the stems with oil and see how they feel then.
They blue checked fine but I will still do a light lapping to clean the seats and faces up a bit.
I have new seals for it but I will wait to take accurate measurements of clearance.

[grcamna2]

So I’m checking the valves out. The guides and valves were done in 2009 and I’m sure there wasn’t much wear since then. The exhaust seem fine but the intakes seem loose. I just ordered a small bore gauge to get an accurate measurement but in the mean time I used the dial indicator method in the shop manual. The exhausts come out at the top of the service limit using that method. I’m not too sure that’s accurate but they also feel loose. I’m going to coat the stems with oil and see how they feel then.
They blue checked fine but I will still do a light lapping to clean the seats and faces up a bit.
I have new seals for it but I will wait to take accurate measurements of clearance.

Do you have service history from the PO saying which parts were replaced? I would want my intake guides/valves to be well within spec as worn ones pull-in oil.

[MauiK3]

New guides, valves, springs, seals. When I get my hole gauge I’ll know for sure.

[MRieck]

As I recall, Duplicolor high temp semi gloss or satin (have to check) black engine paint is one of the “correct” choices. And I’ll be baking it some in our oven since I don’t have anywhere else.
I’m starting to un-blank the cases and I’m happy that there is very little glass intrusion inside. I found a small amount near the starter mount hole. Of course I’m going to clean like it was full of glass but I’m more confident now that I won’t have any major amounts to deal with. That stuff gets everywhere!
I may build a wood box I can break down and store for the odd blast job that may pop up. It has to be larger with easy to use gloves, I’d want a 90 degree swivel on the air fitting, a view window/door that holds itself open, or a side door. 1/4” ply would be enough with a little hopper in the bottom to return the media back to a bucket.
My spokes are here, I can build wheels. Just like I thought, I have lots of work to do now. No hurry, we have a long riding season.

PJ1 satin black case paint is a fantastic product. Have used it many, many times on cases, heads and cylinders. The RC Engineering triple cases wear it. For silver the Duplicolor engine enamel.....excellent product.....no primer necessary......bead blast the surface.

[69cb750]

Valves are .274", guides are .276"
If valve moves sideways in guide parts are worn.

[craz1]

PJ1 fast black is also what I have been using. High temp satin. It will bake with engine temp but pre baking it also helps a bit. takes several hot engine cycles to cure. My 73 has been done for 12 years and looks great. If you use the home oven you will need to clean it very well as the fumes are pretty strong. I would not bake a pizza directly after. You can put the smaller parts in the gas barbecue but watch the temps. Watch those liners in the cylinders

[MauiK3]

Bike looks great!

[MauiK3]

After 2 Simple Green soak and washes and blow down with compressed air, spray down with acetone, spray down with denatured alcohol, squirt through passages and bolt holes with Brake Clean, wipe down with white paper towel and flashlight inspection, copious and tedious taping off, I’ve started painting the engine.
I’ll post photos when some of it can be handled.

[MauiK3]

Got the cylinders painted, the edges were a treat. They are not very we’ll finished from the factory so I had to worn on them some. Pretty rough as found. Got my bore gauges today, Mitutoyo, nice stuff. Intake guides are right in the morning middle of the spec, good news.

[MauiK3]

Oops, wrong photo. What that photo is I am test assembling the cases and I can’t seem to figure out how to get the kick starter assembly in right. The manuals are vague and an old video I found skips over it. It must be simple and I’m just not seeing it.
Here are the cylinders.