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Hey guys, I have slowly built up a decent set of machine tools in my home shop and with winter coming and the race car season soon to slow, I will be back in my shop more often.

Right now I am doing GT750 water pump gears and squish band cylinder heads, but I am expanding into air cooled cylinder bore and hones. I have all the tooling, but depending on the cylinder I may need to make a flex plate.

I can also do a range of custom machining. Brake spacers, custom cylinder had shapes, rear set brackets, etc.. Just inquire with me and will see if I can do it.

GT750
Center plugs and machine head with squish - $450
O-ring head or Cylinder - 300$
Billet High flow Water Pump Impeller and Cover - $400
Billet Aluminum Water Pump Gear - $135

Cylinder bore and hones (and chamfer)
$100 per cylinder

This isn't my full time job, but I try to get jobs turned around as quickly as possible. Lately things have been moving pretty quickly. Feel free to post here with questions.

Not sure if we have any F1 fans here, but I came across this pic of him.



Anyways, he retired this year, but the guy was always a class act. It's a nice GT750 too.

https://bringatrailer.com/listing/1989-evans-automobiles-kudzu-series-i-gt/

The ad is slightly incorrect, the chassis was built in house by John Evans and was used as an EPA test mule. The chassis bears no resemblance to the Kudzu IMSA Lights chassis, and John Evans never worked for Jim Downing at all. Evans simply purchased a used DG1 Kudzu body for this test mule, thus inheriting the "Kudzu" designation, despite have no mechanical relation.

Nevertheless, it's a neat piece that could probably be pretty fast in the right trim.

I wasn't sure of the technical name, so I called it the "brake shoe plate." I am referring to the external plate that supports the brake shoes on the rear drum of an RD.

I know many have added various weakening holes to remove some weight on these parts, especially so the shoe plate. I finally have a spare plate to do some work on and plan to come up with a nice program to do this work on the mill. I'd like it to have a classic look while also removing as much mass as possible. I'll probably try to do some rudimentary failure mode analysis to make sure I'm not getting too crazy.

I am not a huge fan of the Swiss cheese random hole look many achieve, but done well I think it can work. I have seen some drums with reasonable size holes and stainless mesh riveted in (certainly on English bikes). I much prefer that look and I think it will achieve the best performance, but with the webbing on the back of the plate there was to be some consideration to where material can be removed and how much can be taken.

So, if anybody has some sweet photos I'd love to see them.

Let's hear what you guys are doing with your coffee.

I've done everything it seems. I started with drip, moved into a french press, then did pour over for a while. Now i'm using this el cheapo k-cup machine called a "Chulux" that actually make some pretty good coffee. It makes better coffee than any Keurig I've used, and I've used at least four of them at my office. That said, I hate the waste and I'd like to get back into shorter coffees.

What caused me to create this thread is that I recently finished up a bar addition that connects my kitchen to my dining room. It's perfect for an espresso machine or other coffee device. Especially since I effectively work from home these days and the bar has become my de facto work station since my wife uses the home office for her college work, and my son uses the kitchen table for his remote preschool learning (we are running out of spaces for computers/work).

Anyways... I've always loved a really solid cup of coffee. I figured the cultured 2t lovers here could tell me how it's done.

What do you guys like? 25psi seems very good on BT45's on my fairly light RD350. Much  lower and they just get too flexible. Going up 5 seems good. 35psi is definitely too high, they get a tad skatey. Perhaps a sign I have to much low speed damping... I've tried as low as 15 but the front end gets mushy like I'm riding in sand.

https://dirtbikemagazine.com/forgotten-700cc-2-stroke-giant-throwback-thursday/

It looks like a real monster, and that stainless frame certainly is unique.

The ad at the bottom of the article is interesting. One of my father's best friends test road for ATK for a long time through the 90's (and even tested for Cannondale before they fell apart), the last I heard he still owned something like 25 ATK's. I've had the opportunity to ride a few of them on various occasions, that rear brake always sucked if you ask me. I did like the rear suspension performance under braking, but braking power wasn't amazing and the heat can be felt through the boot after a while.

So I bought this bike from a member of the older forum and gifted it to my wife as an engagement gift. She loved it. Well since then we got gentrified out of our neighborhood, married, had a kid, bought a house, and lots of life has happened. I did manage to get the bike running for her, but I was never happy with it in that it intermittently developed a mis and or high rev, indicated a vacuum leak.

So... that brings us up to the realities of our pandemic. I'm laid off and loving it. So I started a decent rebuild on the 125. I have a nice parts list that I will be buying from the UK, mostly an engine rebuild including the rods, pistons, and a bore. Obviously all seals while I'm at it. The wiring looks good. I have it all working, the battery charges, lights are good (working). So I'll clean up the frame, have my dad fix the left rear turn signal bracket that is bubble gum welded on, keep the build pretty basic. I'll apply some black spray paint to the frame to finish it. I want basically a stock bike here, I don't have any plans on touching the stock paint. The bike has seen some action and it is going to stay that way.

I took the old (not very original and falling off) seat cover off, that lead down a rabbit hole. The foam came off nice, it is in great shape! The pan is solid too, I'll braze up some spots and hammer it around a bit, but it's pretty solid. A new cover has been ordered. Getting that on will be a new experience. The aluminum trim strip and all that hardware isn't something I've done.

Here's a few pictures;

What do you guys think of vibratory tumblers?

I'm thinking about picking one up. I'd probably most often want to toss machined aluminum bits in it, but it would be nice to clean up old bolts, brackets, etc., that will likely be steel.

I was thinking about going straight for the 18lbs unit, likely from Harbor Freight as I have a store about 3 miles from home. They also have good prices on media and I won't have to pay shipping, which is nice. I checked out the media from McMaster, it's quite expensive IMO, but the quality is probably there.

The worry I have is that I'll never get nice finishes or that I'd be better of with a polishing wheel. I don't mind letting parts run for a few days, but if I'm never going to get get a nice finish out of the thing then it's pretty useless.

A little history on the project, my father built this car from '72 to '74. It was successfully given a log book and SCCA homologation to compete in the D-Sports Racer category. This chassis predated the modern steel roll cage rules, meaning an all aluminum (crash structure) construction was allowed, including the crash structures. Additionally, there was no minimum weight prescribed for cars under 850cc. The car is basically an aluminum monocoque, or maybe better described as a semi-monocoque as it uses effectively an aluminum tube frame with riveted and bonded panels. At the time of build the Suzuki GT750 was a popular engine, and given a proper tune could make over 100hp easily. The first engine build was performed by Eric Buell, this was back when he still lived in Pittsburgh. Later builds were performed by my father, and the engine evolved somewhat over time. The chassis was engineered by my father's friend, who at the time was a full time engineer at GM. My father constructed the car with the help of another friend and his wife. The car was raced from '74 to '79 with mediocre success and then mothballed. They participated at Nelson Ledges, Summit Point, and Mid Ohio, but with a limited budget and limited man power they never quite got it going like they had hoped. The car remained in the garage unused for 40 years. It had become such a burden on space that my father eventually mounted the car on the wall, it stayed there for something like 16 years.

Here's a bit of photo history of the car.











Here's the car as we were pulling it off the wall, I want to say this was in 2015, maybe 2016. It's hard to recall.





Once off the wall we put the car back on the fabrication table that it had sat on for something like 20 years before. The process began. The all aluminum crash structure simple wasn't adequate. After 40 years of competition in other areas of racing my father had learned a lot from the days when he built the car. So he took the chance to update and change a number of items, but tried to be sensitive to keep the original spirit of the car. The focus was mostly on engineering issues, especially those that could be a safety concern.




Progress





And, this last weekend we got to the track and managed to race the car. We fought with the master cylinders right up until the race, but managed decent brakes come race time. Then of course the car overheated. But I managed the best laps of the weekend in the race, so for having basically used the race weekend for testing it was a positive result. We simultaneously got the car on track for it's 40th anniversary of retirement, and my 25th anniversary of race driving competition. A true success!


https://youtu.be/pH5OCOBPmZg

I have other pictures as well. I can also publish more detailed specs if anybody is interested. We plan to continue development of the car. It actually fits the rules for the modern P2 class which is sort of the modern equivalent of D-Sports Racing. So we could compete in national competition if we wanted, of course the car wouldn't be competitive, but it would be fun.

So the petock on my wife's RD125 is bad. I've been switching the one on my 350 back and fourth between our two bikes over the years.

I'd like to stop that.

I see economy sells a nice reproduction, but for $80+ shipping, ouch.

I'm thinking about machining a bolt on bit that will adapt a Honda pipe thread petcock. Clearance might be a

Has anybody done this? I'd rather not braze a bung on, but since her tank is so-so, I am considering it.

Petcock I am thinking about adapting:

https://www.ebay.com/itm/Fuel-Valve-Petcock-Honda-CL175-CB350-CL350-SL350-CB360-CL360-CB450-CL450/362585186045?fits=Model%3ACB350%7CMake%3AHonda&hash=item546bc2defd:g:TAQAAOSwoG1ciq84:sc:USPSFirstClass!15214!US!-1&frcectupt=true

One of the most valuable threads that needs to be built here is the regulator and rectifier thread. We all know that the stock components suck.

This is the common rectifier that is used to replace the stock components.

https://www.ebay.com/itm/Bridge-Rectifier-50A-1000V-for-3-Three-Phase-Diode-PMA-Wind-Turbine-Generator/271997001394?hash=item3f5448deb2:g:MGgAAOSw0e9Uy9L2:sc:USPSFirstClass!15214!US!-1

This is a great low cost choice for the regulator.

https://www.autozone.com/batteries-starting-and-charging/voltage-regulator/duralast-voltage-regulator/130153_6248_24818

The wiring diagram is simple. I'll draw it up sometime soon.

I think this combo works on a lot of bikes. There are better options out there too, but this one is really affordable.

I mounted up some knockoff Mikuni's on my wife's RD125 using DT125 reed blocks. Everything is great, the bike starts right up. The only issue is that the stock cables are too short.

I've considered using a dremel or something similar and shortening the sheath a bit, but ideally I'd come up with a slightly longer cable. Since I don't have the stuff do this myself I'm in a bit of pickle. I did some googling and asides from finding a couple tutorials I've come up with basically nothing.

Thoughts, ideas?

My father and I are finally getting his home built GT750 sports racer back together for some vintage racing. The chassis work is closing out and it's now time to go through the engine. He has the engine torn down, we've read about some various modifications and changes to the crank to achieve greater revs, but we are also sure that things have changed drastically since he built the motor in the early 70's. It's got pretty drastic porting modifications with the cylinders raised and decked and has hand built chambers and some large VM's. Seems like the intake rubbers are totally shot as expected, so those will need to be replaced, though they aren't stock dimension. He created an adapter plate the widens the stud spacing for the larger intake boots. Anyways, it's a bit of project...

Seeing as this car won't see any truly competitive racing we don't need crazy performance, but something reliable and a bump from stock would be good. So, who is building water buffalo cranks and what configuration should I be looking for/ordering?