My project '91 ST: A UJM for the 90's

Mak, I don't think a few grams will make any diff. The stock pistons are steel, no aluminum. I think(?).

I.D. is 22.6~.7. I drew mine up with a 2mm wall and base, so dimensionally they should be about the same. The OEM pistons are steel (apparently with a coating) as evidenced by a magnet sticking to them.

The CBX vendor emailed me and said his main supplier was on back order until next month, but his secondary source had enough for my order & they should ship next week.

I can get a couple dozen made for < $300, anything smaller than that & I'm in the range of OEM pistons. I just don't want to spend the $ when there's no demand. for them.

I thought the same George. The weight couldn't be that big a deal. Hydraulics, they work well
On the demand front, I can't see that there would be a big one, I think you would be holding piston so long that it would be a hassle. JMO

A hassle is what my gut tells me. If I were to pump money into something, I see a far greater need for reasonably priced rotors. That would require over $2K to get underway, so it's not going to happen. I have the above piston & rotors as an .ems (CAD) file if anyone would like to pick up this idea.

My paint stuff arrived yesterday, but it's been too cold or windy to paint. I did shoot a layer of gloss black chassis paint inside the shop on my spare wheel that had been sandblasted when I did the pipes. I'm working on filling cracks & sanding chips on the tail section and will then go to the right side panel & shelter. The left side panel is in a group of used parts I bought & is not here yet. I think the bike will look sharp with white plastic and black wheels & fairing/trunk. I'm no master painter, but I can produce a "10 footer" OK. Considering how rough it was a month ago, that's a huge improvement.

The tires & brake pads also arrived yesterday. I made use of my Harbor Freight tire changer with motorcycle wheel attachment, and it has almost paid for itself. The front tire was a lot easier to remove than the rear ones, but all of the decrepit tires are now off the wheels. Today I shipped the front wheel to Will's Rims in South Carolina. He has a lot of great results on various boards, so I'm confident he'll do a great job. Once it is returned, I can blast & paint it then mount the Avon tire I bought. I also found a set of supposedly low mile used rotors from a '91 and have them on the way.

While I was out, I picked up a bucket of carb cleaner so I can dip the carbs. I got notification today my OEM parts (to include carb kits) has shipped from Texas, so they should be here by the middle of next week.

I got a bunch of metric socket head bolts today to replenish my stock. I'll use these as I can for stuff like mounting calipers, the fender, etc. I also got a 12" x 10" piece of 3/8 aluminum I'm going to make into a trunk mounting plate. It was like $23 at McMaster-Carr, who by the way are an excellent place to buy from. They shorted me some brass washers in that order, so I emailed them yesterday. This morning they delivered another bag via FedEx. That's customer service. :yes:

I replaced the dash bulbs in the broken dash with blue and then red LEDs. The blue has a nice look to it, but the numbers were not as visible. The red worked out well, and this also saves me $20 on the combo gauge I'm going to buy- blue is more expensive for some reason, and as I recall harder to see during the day. I've also got new LED replacement bulbs for the dash idiot & indicator bulbs. I tried to take some pictures but my camera doesn't work in low light.

Tomorrow I'm going to look at a WJ for sale locally. It has no headlight but the picture and description indicate it is in above average shape (good paint, no cracks). The seller has a bunch of stuff FS as a package I don't need, but I think he may split the fairing. Hopefully it will sell for a reasonable price, and I'll have another part out of the way.

I found some Harley fairings on eBay and they are interesting- they have openings for gauges, which is what I'm using the fairing for. They're big bucks though, out of my price range.

The ST looks rather puny with no seat, tank, or wheels. It will be nice to start bolting clean & polished/painted parts back on soon.

SHP, I have the red bulbs in both STick and ReSTored. Haven't bothered yet on lipSTick but she has a bulb out so should do it soon. Agree the red shows up better in than the blue.

I got a 2 for 1 on the fairing. The seller had a weathered one that was banged up a bit and I got both for $75. I didn't notice a crack on the inside of the "good" one until I got home, but it's repairable.

I did some test fitting, and the physical install & fork clearance won't be an issue. I can trim up a piece of 2x2 angle iron on each side and run a leg down to the 6mm nuts on either side.

The issue will be the gauges. I held up the panel in several positions, and there is no clearance (even with the fairing further forward) for the cluster. The key switch is in the way among other issues. I could possibly mount the cluster to the fairing, but I'm not sure how good this would look. I think the best option is to get some shallow digital/electronic gauges (i.e. Intellitronix) and make up an aluminum panel. If I do this correctly, I'll have an opening for the key switch and room for all of the gauges I wanted to use in the first place.

Here's a pic of the fairing test fit. It balances fairly well, just needed a 4' piece of angle to hold up the front:


Three new tires (Michelin Macadam 50s were half price, so I got two).


Painted forks & calipers:


Spare rear wheel:


It's not too bad out today but still too windy to paint. I'm going to treat the gas tank and do some more cracked parts repair. Good thing I bought a super-size box of JB Weld.

I've used the Macadam 50 on the 1100. Not a sport tar but gave good service.

I've been measuring and doing some test fitting so far as the gauges go. I cut out a cardboard template of an aluminum panel that would hold two 3.375" gauges (3 & 3/8" is a common Autometer et al aftermarket speedometer size) plus four 2" gauges and mount on top of the triple clamps in front of the bars. It was 10" wide and 8.5" high. The top of it would hit the fairing inner part, so I reduced it to 10" W x 4" H and it cleared fine. It looks like I could increase it to 6" and add a 2" gauge at the top. Here's the issue:

The key switch is basically right where the OEM cluster needs to go. It looks like I have three options-
1) Relocate the switch & bolt up the cluster. Advantage- lowest cost, retains idiot lights in cluster, existing wires & speedometer cable will probably fit OK, can use new water temp gauge I bought, two less aftermarket gauges needed. Disadvantage- loss of fork lock function.

2) Remove temp. gauge from cluster & mount over top of key switch. Advantage- switch & lock function retained. Disadvantage- good bit of surgery to the cluster, key will be too short to easily access. Not really a viable option.

3) Make aluminum bracket and mount aftermarket speedometer, tach, and possibly fuel gauge & thermometer (see attached). Advantages- Key switch stays in stock position, can use a wide variety of 3.375" gauges, plus could go all digital. Disadvantages- have to adapt cable driven speedometer to either mechanical or electronic speedometer, rewiring of gauges, splitting idiot lights up to fairing, extra cost of gauges.

In any of these options, I will mount the remaining 2" gauges across the ledge of the fairing, that way I don't have to fool with the cycle sound setup.

What I'm leaning towards doing is to try #1. Since my shelter is being refinished (the crack has been repaired), I will try to find a shallow key switch that will fit between it and the air filter housing. If this does not work out, I'll have to try #3 with another shelter.

In the process of sealing the gas tank, I pulled the sender unit to test it for ohm range in case I used an aftermarket fuel gauge. Good thing I did so, as it was all over the map. I took it apart and the winding inside was worn, so it has to be replaced with a used unit (no longer available new).

Now is a great time to be planning. It's going to be too cold or to wet in the next few days to do any painting or coating. The gas tank coating came out pretty good. I saw a couple of spots that had started to rust, so the tank should hold up for years to come.

Just a suggestion as to the caliper pistons, have you considered buying used calipers on E-Bay? they seem to have them all the time for cheep...

I already have new pistons on the way. The problem with used stuff for high-risk areas like brakes is that you don't really know if what you're buying is any better than what you have, i.e. the 4K mile parts of a 1992 ST may have sat exposed and the calipers are locked up solid like mine were. Then it's back to square one. I didn't really have an option on the rotors, I hope the used ones I bought are OK, supposedly they are from a <12K mile bike.

I'm really tempted to sink some money into the rotor project. If I only make a couple the expense is far less & I could test them. There has got to be some others that would want a made in the USA rotor for like $100 less than the aftermarket ones.

Used part batch #1 arrived which consisted of the handlebar switches, a side cover, and a horn (complete w/ bolt ). I spent the morning extending the wiring for the left switch- the right one looks like it will be OK.

I've also mapped out the front brake & clutch lines and ordered some metric & AN fittings to make use of some AN hose I have leftover from another project.

I spent a couple of our cold days here reading all about Koso, Acewell, and various other speedometer or gauge panels. I even mocked up some gauges with cardboard to see how the would fit with the Vetter in approximate position. I really liked the Acewell ACE-3252. The price was reasonable ($185), and it has a digital gear indicator built in, but the gauge is tiny. I suspect there would be an issue trying to read it while riding. The Koso RX2 would be a better gauge for size, but it is over $300. I even found a Chinese knockoff of the Koso gauges on eBay for $90 shipped. The video in the auction showed the quality- normal gauges sweep the needle from 0-max range when it is powered up. On these, it went to 2K and back to 0. Of interest was the fact the speedometer was cable driven- all of the Koso gauges are electronic.

As it stands, I'm going to try out the OEM panel and mount a small water tight box (Hammond 1550WDBK, $20 shipped) on the top of the fairing to mount a combo oil temp/pressure gauge, and digital voltmeter and ambient temperature gauge inside. I will mod the cover to make a Plexiglas portion so the gauges can be seen. I can also mount my navigation/audio device on top there.

More to follow.

EDIT
Pics from today-
Box with hundreds of $ of new parts:


Old (left) and new gauge panel parts:


Old & new switches:


New switch with extended wiring:


The only good thing about the frosty weather here is that my arc welder cycles longer. I got the winch bracket welded for the bike trailer so i can install it soon.

A couple more things came in today- the large eBay trunk and some hydraulic fittings to plumb in the oil pressure and temperature senders.

The trunk seems like it was sold to someone else & returned- the parts bag was opened, and it won't latch onto the mount plate. The latch opening is about 1/8" off. I can file it to fit, a lot less hassle than trying to exchange it. I didn't expect much for like $65 shipped, and the thing is large x huge, so it will serve the purpose.

Apparently I'll need a longer choke cable (+ 4~6"). I measured the OEM one at 22.5" housing & 31.0" overall. It looks like the other V4 bikes like the VFR800 or V45 Magna may use a longer one. I asked a question to an eBay seller that had some listed & they wouldn't tell me the length, since this "got them in trouble".

I'm going to have to finish the bulk of the photo work here by next month. My ISP is capping the monthly usage at 5GB, and I'm over 8 so far this month!

We may have some 70 degree weather here next week, so I can spend a day or two painting & coating. Sure hope I can get this jewel running!

It was warm enough in the sun today to get a few things done. I got the exhaust coated, from the head pipes to the mufflers, and rattle can painted the tank & final drive unit.




I installed some 1/8 brass piping to allow for oil temp and pressure senders under the right side cover. The sender seemed like it was 1/8 pipe, but the hole in the block wouldn't accept either a 1/8 pipe elbow or a British 1/8 pipe elbow I bought. I tapped it with a 1/8 tap so all should be good. All of the senders have to ground through this setup, so I didn't use any sealant. Hopefully no leaks!




Mocked up two pieces of 2x2x.125" angle for the fairing mount. If it wasn't for the thermostat, this would be a piece of cake. As it was, I had to notch one of them and will have to relocate the thermostat housing inboard a little. I can use the same thermostat bracket, just have to redrill a hole for the bolt. Will have to shorten the inboard hoses and find about a 60 degree top radiator hose.




Still a lot to do.

I spent some time looking at the dash issue again & sometimes the simple stuff is overlooked.

If I mount it on the fairing (as it was originally), there is no issue with the key switch and I can accomplish this with a couple of L brackets. It will look rough having the wires etc. hanging out, so I'd like to know how it mounts on the OEM piece. I found a picture in our members galleries here, but can't link it.

I take it that it is rather involved to get the plastic that surrounds the dash. I'm not sure of the best method to cover the rear of the cluster.

I also noted the upper radiator hose is about 1" in diameter, and the two hoses going to the thermostat housing are about 3/4". I'm looking through a Gates catalog to see if I can find a hose with about a 60 degree bend in it that will work for the upper radiator hose, and will look at 3/4" hoses while there.

Three of my clutch & brake parts came in last night, so I can start work on a bracket for the brake tee.

I've been away a few days & worked a little today on the fairing mount & thermostat housing as well as a few other things.

This is a tight fit & I was looking at relocating the thermostat outside the fairing, but it looks like this may not be needed. The conflict is between the right fork tube if the housing is too far forward, the fairing mount (on the fairing) if it is too far outboard, or the frame tubes to the hoses if too far inboard. It should fit slightly inside of the OEM location. I used a 1" hose with about a 60 degree bend in it to connect to the radiator, it is Gates part #22519. I'm using some 3/4" silicone heater hoses to replace the OEM molded hoses and smaller silicone hoses for the other two. I'm going to replace as many of the rubber hoses here as possible- they are super-crusty.

I updated the fuel pump thread here, so in a nutshell, I'm going to use the Airtex pump & strainer. I want to modify the setup so it picks up fuel from the bottom of the tank for maximum miles per tank- the OEM location mounts the strainer 90 degrees off from the bottom. I'll either fab a 90 degree elbow or relocate the pump to vertical.

I also got the front brake plumbing roughed in. The AN-3 tee will work well bolted to the forks in what I think is the OEM location- I made a simple bracket to mount it. It occurred to me that rebuilding this bike when I don't know where everything originally went is similar to the old Star Trek episode where Kirk's predecessor (Pike) had crash landed on an alien planet & the aliens used an illusion after they put him back together since they didn't know how he was before the crash. Anyhow, the 21" lines from the tee to the calipers are too long, so I bought a couple of AN-3 hose ends so I can cut them to size. I'm using 35 degree 10mm banjo adapters at the calipers and they look to be a good fit.

Ditto the clutch line. My hose is AN-4, so I need to get a 10mm banjo to AN-4 for the master & slave cylinders. It's actually cheaper to do this than to make another AN-3 hose, since my AN-4 hose has ends on it I can use.

I resprayed the spare rear wheel and am not satisfied with the outcome, so I will redo it. It still has not really been warm enough here to paint, especially when I'm mixing Rustoleum and mineral spirits.

Pics to follow.

The cold & flu season has taken its toll on us here, and I've been sick for several days- no real progress on the project. Probably didn't help that a few days ago I tested out some heated gloves in 30 degree weather on my GS (they didn't help).

I got an email today the front wheel has been repaired & will be shipped back soon.

The CBX caliper pistons arrived & I test fit them- with the pads in place, I have an opening of almost 8mm, and the rotor new is 5.6mm (my used ones are much less, like 4.8). I think they may work as-is. I found I need a few more small brake parts such as retainers & springs, so I've ordered them.

The AN fittings for the clutch & brake hoses have arrived, so all I need to do now is cut the hoses and attach the new ends.

I've also installed an Airtex fuel pump. I found the hose that came with it is not rated for immersion in fuel, so I ordered some SAE J30R10 hose that is.

I've got the gauge panel back together with the Autogage water temp gauge in place. I tested the lights out with a 12V power supply and from a normal riding position it should be OK. The gauge doesn't fit flush like the fuel gauge does. I also have a small sealed box I'm trying to squeeze a combo oil pressure/temp gauge into along with a digital voltmeter & thermometer. The first thermometer I got was listed as Celsius & Fahrenheit, but when I got it I found it was only Celsius, so I've found another one that is supposed to do both.

Still need to redo the carbs, this is the main mechanical project left aside from bolting everything back together (thank God for the shop manual). Then when we get some warmer weather (won't be for at least a week) I can try my hand at some more painting. I got some decals on ebay for the tail section that closely matches the HONDA one there, as well as some wing decals for the shelter that are similar in appearance to the OEM ones.

Some pics-

CBX (left) vs. OEM caliper pistons:


AN3 tee mounted on aluminum bracket:


Added gauge box w/ eBay voltmeter & thermometer installed:


Thermostat housing test fit:


Gates 22519 upper hose in place:

Hello 'Bud' [what's your real name?]

Great project and forum updates! Love hearing about a classic 91 being resurrected. BTW, they're the only ones with the external crankcase breather box... unique water pump too.

Brand and model of air temp gage? Is is lighted/backlit?

Regards, John :STOC: Ten Fifty-Eight

John OoSTerhuis said:

Hello 'Bud' [what's your real name?]

Great project and forum updates! Love hearing about a classic 91 being resurrected. BTW, they're the only ones with the external crankcase breather box... unique water pump too.

Brand and model of air temp gage? Is is lighted/backlit?

Regards, John :STOC: Ten Fifty-Eight

Click to expand...

Not stated to offend, but unlike many of the younger generation, I don't post my personal info all over cyberspace. I'm in the RAN list if this is really important.

That box is in the way of my oil senders! Should have bought a '92!

The water temp gauge modification is in post 12 of this thread.

ST_SHP said:

Not stated to offend, but unlike many of the younger generation, I don't post my personal info all over cyberspace. I'm in the RAN list if this is really important.

Click to expand...

I was just asking for a first name... feels kinda funny calling a hopefully new-made friend "ST_SHP"

The water temp gauge modification is in post 12 of this thread.

Click to expand...

Oh. I thought the rectangular LCD gage in poST 61 above was an ambient air-temp gage.