The missing plastic baffle probably disintegrated, and may be partly responsible for the white powder if there is no obvious corrosion in the upper part of the chamber. It should run without the baffle, but might have a stumble on hard acceleration or some similar symptom due to fuel surging away from the jet.
A baffle makes sense. Knowing that, I found a used one for sale on eBay for $28 without shipping. So I sort of fashioned one out of some brass shim stock and got it to fit enough to get the carb back together and on the bike.
Over the course of the day today I was replaying taking it apart and cleaning it in my head while looking at Mikuni stuff on the internet. And it occurred to me that my pilot adjust screw is missing some parts, namely a spring, a washer and an o-ring.
So despite setting it to the spec in the manual, I'm thinking it's still in the wrong spot. If anything I made a lean condition leaner.
But I put the bike back together and kicked it over four or five times just to see if I'd get lucky and have it start. I did not.
Replacement parts are on the way from Moto-Labs, so I'll take it all apart again after I get them.
A pic of the bike with the tank off-
Otherwise I cleaned out the completely plugged drip tube from the air box, and re-tapped the rear two mounting holes for the tank. A couple screws from the hardware store will get that mounted back up.
I like motorcycles...
White stuff in the carb bowls could also be from ethanol reacting with the material in your fuel system. Some metals, like those found in carb'd systems, do not like ethanol. Before running the Generac gen we picked up for storm season down here, I dumped some fuel treatment in the gas to prevent any buildup. Got it at the car parts store and while it doesn't remove the ethanol (that would be some crazy stuff to actually remove ethanol from fuel) it does neutralize the negative interactions. Or at least says it does. I believe there is a recent build thread about an old Kawasaki floating around where this is discussed in greater depth.
Without the airscrew o-ring you've got a carburetor air leak. It shouldn't necessarily keep it from running, but it will keep it from running well. The spring keeps it from backing out due to vibration.
In reply to Error404 :
Was the build thread for a 1971 Kawasaki H1?
The PO of my bike said he put 93 fuel in it, and that is what I topped the tank off with- with some Marvels Mystery (snake) Oil mixed in for good measure.
In reply to paranoid_android :
It was. The metallurgy in some older motorcycle carbs doesn't play nice with modern pump gas.
The white shield around the main jet likely acted as a fuel baffle to keep gas in the bottom of the bowl. Step one for me with old carbs is to set the fuel float bowl height. If you leave the fuel valve open, will the gas eventually pour out of the overflow? If so, your spring loaded float valve or its seat are gummed up. With the bowl removed, fuel flows freely. Lift the floats gently and the fuel flow STOPS. No trickles. Nada. Silicone around the bowl cover says nothing good.
A $5 set of fine wire Torch Tip Cleaners will unclog every opening, passage, orifice and jet you can find, follow up with spay cleaner through a straw. Compressed air through a blow gun if you have it. As noted above, every o-ring needs to be present or you will be sucking in some un-metered air.
If you have to start it cold off choke, something ain't right, likely clogged carb. Are there any tiny holes in the floor of the carb throat? Chase those with the finest torch tip cleaner wire.
As to kick starting, I regularly kicked a 74 CB750K with high compression 811 Weiscos. First kick, every time. My method was Full Send. Left foot on the peg, Right on the kickstarter with the pawl in the arch of the foot just ahead of the heel bump. Hands on the bars. A slight upward hop and then every ounce of your weight drives down on your right leg through the full stroke. Never had it try to kick back and bite me, but it's not a big thumper either. That said, I did the same with a KZ750 twin. My theory is if you half-ass tap it, you can load it up on compression stroke just shy of TDC and without much speed or power, it kicks backward. Show it you mean business and even if it hits compression at the bottom of the kick, it should have enough inertia to roll past TDC through power stroke.
Learn to wheelie, put your inside leg down in a powerslide, and crash in a wide open field somewhere. Trees hurt.
Use an air gun to blow the old hand grips right off the bars from the inside edge.
Have fun,
Brian C.
Changing from the carb topic to getting the bike road legal-
Michigan offers this nifty form for folks to print out and take with them when their motorcycle is to be inspected by the po po. This is the first step in getting an "off road only" title changed into an "assembled vehicle" title as I understand it. It also spells out what must be present on the motorcycle.
There are super nifty kits out there that do this very thing. But I'm cheap, and pushing the easy button isn't always that much fun, so I nerded out instead.
This Suzuki has a stator on it, and based on some research it is good for 90 watts at 12 volts ac (single phase). In stock form it powers two lights (halogen) and the ignition system. Not knowing what the ignition system draws, the goal I decided on was to power headlight, tail light, brake light and a horn utilizing the wattage those two stock bulbs were using. With LEDs, it didn't seem to be too hard.
Bench testing the halogens and the LED replacements I guessed at showed the following:
So far so good. I even have 6.5 watts at 12 volts to spare. That .5 amp should more than cover a brake light, and eventually even turn indicators.
This is the cheap Amazon crap I bought to serve the purpose.
The biggest mistake I made while shopping is not verifying the bulb type that was in my bike. Reading indicated it should be an H4 base, but it isn't. I guess maybe it's an H3 base something or other?
So at this point I have to decide if I should return the H4 LED bulb and try to find the same thing in an H3 package (if there even is one), or find a headlight housing that will fit in my fairing that's accepts the H4 bulb I have.
Ill think about this while I'm at work tonight.
Almost forgot too, I'll need to remove the voltage regulator that came on my bike and install the rectifier/regulator in my pic above. LEDs are all about the DC, yo.
There's some strange tomfoolery that goes on with bike electrics. I'm still trying to learn. The stator can have poles that are wound to do different things, most commonly one pole that drives the ignition and the rest that drive the electrics with dirt bike lights often running right off the AC. Then you get into converting the AC to DC through the regulator/rectifier and whether the stator is grounded or free and odd bikes that have enough poles that they have both AC and DC circuits and whether you need a battery for the DC side to work and..... I'm going to follow along and see what you do.
¯\_(ツ)_/¯ said:
He certainly does- thank you for the tip!
A small, cold side adventure for a free trailer.
The short version: Adrian offered up a small trailer for free, I made plans to go get it that got screwed up, AngryCorvair stepped in to save the day.
On the way to Angry's I stopped at Harbor Freight for the parts to get a 1 7/8 ball on my 1 1/4 hitch. A hokey solution, but should go together easy.
Nope.
But two guys with an angle grinder can make it fit.
And one incorrectly sized hitch pin was replaced by a wheel stud modified to accept a cotter pin, along with a very fine castle nut.
And my hokey hitch set up made the trailer chains too short.
Ugh. But it all ended up going together enough to be roadworthy, including the lights. They are going to need some attention though.
Just as I was going to take off the sleet started:
Yes Michigan!
The trip home went without any drama, and I have another little project to work on.
Thank you Chris, Adrian and Angry!
What looks like a wildfire raging in my neighbor's backyard is just the sunlight being dispersed by the clouds. It was a strange bit of weather.
Looking at the NASA Rally Moto section is less than helpful. Do they run motos at every event? Should we buddy up and do the Central UP Rally together this coming year?
In reply to mazdeuce - Seth :
You have to look at the Supplemental Regulations for a given event. I don't think Central UP had Moto last year, so the only thing they have on the schedule for bikes currently is Sandblast 2020. If Bill Conger runs his RallyMoto training class before Sandblast as usual that is also something to look out for. Unfortunately with the loss of Magnum Opus and Black River the two wheeled US rally scene has been very, very small lately.
There is a thread on ADVrider where the RallyMoto guys hang out: NASA Rallysport Banter, as well as an event specific thread in the racing section that usually pops up around when registration starts filling up. There's also a largely inactive Facebook group: Association of RallyMoto Riders of North America (ARRONA) which has had discussion on adding bikes to other NASA events in the past.
In reply to ¯\_(ツ)_/¯ :
Thanks for that update. I knew the rally scene was still shrinking. Consolidating? But I didn't know that it had shed the moto events to that extent. Maybe I should do do Sandblast while it still exists as a moto event.
Sandblast 2020 is the goal that has been in my mind. I'm not sure how much riding experience I can get under my belt before then though (hoping for a mild winter here). Interestingly there was a WR250R that entered it this year. From what I know about it from Chris it is a great event.
The last blurb I saw about BRS 2020 was on Facebook, and it stated: "Good news everyone! Looks like we will be bringing back BRS in 2020! Stay Tuned for more updates!" But I don't have the impression many people are holding their breath for it. I would absolutely love for it to happen though, especially with a moto class.
In the Advrider group Chris mentioned, there is a quote from Anders regarding a moto group at CUP Rally: "Get 15 riders together who want to do Central UP Rally and would would actually commit funds and say "Hey, if you'll have us, we'll be there, guaranteed." (You'd need to have a couple well off guys willing to pony up for anyone in the group who bowed out.) Part of the calculation is always "if we do all this work, is anyone gonna bother to show up?""
I would absolutely do this^^^, since it would give me more time to get some riding in.
Edit: I can't even pretend to understand what is going on in the rally scene. From personal observations, ARA is providing most of the momentum by picking up events, but I don't think they've had a single moto class at an event.
Edit edit: buddying up for an event would be awesome! It goes without saying, but is worth saying anyway :-)
I agree, having someone you knew to share the adventure with would rock. I agree the the CUP rally would be better for me, but it's hard to commit to putting together a bike when the rally is unlikely. Hanging out with a plate in my shoulder that has to come out before I can ride makes it reeeeeealy hard to think of doing Sandblast this year. I probably shouldn't have fallen off the Grom. 
The map says it's about 15 hours to Sandblast from my house. Not impossible to come just for support, but not easy either. I'm hoping to bring a plated dirt bike to Michigan this summer. We should hang out.
If either of you runs Sandblast next year I can crew for you... or maybe enter the event with you. I wasn't planning on renewing my NASA membership with almost nothing on the calendar but I could be convinced.
I would definitely recommend getting some practice riding in sand at speed before entering, it's a really tough introduction otherwise. Black River was a much easier event to try as a first timer because at least the road surface itself doesn't try to kill you.
The trailer was mostly taken apart and cleaned up. Michigan is not kind to objects that live outdoors.
The front "triangle" is all welded to the platform now, as some of the bolts didn't pass muster.
I just finished priming it tonight, so it's probably time to figure out how to set it up!
Some rough dimensions of the trailer on a rough sketch (no where close to scale):
The motorcycle at its longest is 82". I think I'll need minimum 76" on the trailer- that's from the front edge of the front tire to the back of the "contact patch" on the rear tire.
The only ideas I have currently are a wheel chock for the front, and a way to be able to remove it so big flat things can be put on it. Like drywall and stuff.
Any and all ideas for a design are welcome since I have no experience to go on 
In reply to paranoid_android :
I would put a wheel chock as far up the tongue as it needs to be to get the weight of the bike biased forward 10-20% and put a plank down to roll it up to there, then deck the rest in whatever way works best for you and add tie downs for the bike at the corners. That will probably put the chock far enough ahead of the main deck area that loading the bike is slightly precarious, but it should also mean you won't need to remove it to haul stuff.
In reply to ¯\_(ツ)_/¯ :
I can work with that.
As for a wheel chock, is this HF one the answer?
In reply to paranoid_android :
Those work fine, easier to use than the cheap bent tube ones.
A small, mildly disappointing update on the Suzuki. The carburetor parts I needed were ordered and received from motolabs. All were installed, got to the float bowl o-ring, oops not the right one.
No bother I thought, send an email and get it exchanged. 20% restocking fee and I pay shipping means I'll eat that one. Ok, can I simply order the correct one? Yes, but it's a special order with a three week wait. They only stock parts for the street model carb (non-pumper).
Lesson learned, on to the next vendor! Enter Niche Cycle out of Florida- they had what I needed. Order received, parts installed. Ready to put it back on the bike-
Put it on the bike tonight. Turned the fuel cock on and went to put my boots on to give it a kick. Came back to a puddle of fuel:
The drain plug I got from motolabs didn't seal despite being tight. Fuel was running out of the float bowl drain. What in the actual berkeley.
The new plug is actually .5 mm shorter than the chowdered original it replaced. Le sigh. Two different part numbers between the carbs? Am I missing an o-ring? Diagrams don't show one.
I'll look into it more tomorrow.
The trailer is almost done though. It's all welded and painted. New light kit is on my workbench. It needs new tires, then it will go to the store to bring home the wood for its decking.
Leaky carb is almost not leaky anymore. Adjusting the float height definitely helped that problem.
I'm still unsure of a couple things though. My final float height is nowhere close to being in spec. This is based on the spec and the measuring procedure in my FSM. In fact the float is currently as low as it can physically go.
Unsure part two: if I tilt the carb 20-30 degrees while fuel is in it (in the direction the overflow is on) fuel starts leaking out of the overflow again.
So this leads me to a learn me on motorcycle carbs. Is this normal for a bike carb to do? That is leak out the overflow when it's tipped? It kind of seems like it isn't.
My testing method was basically connect the carb to the tank on the bike, flip the fuel cock in RES, hold the carb in my hand (close to its normal place on the bike) and see what happens.
Some images that may be helpful, not sure.
Float needle valve
Current float height
Float bowl cover
Jar on the left is the max amount of fuel the bowl can hold. Jar on the right is the amount of fuel that came out of the carb after my last test.
My inclination is the fuel level in the carb is too high. So the float, or the needle valve (or both) are faulty. But I really don't know for sure :-)
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