2019 - Yard Kart Therapy

[gegcorp2012]

Worked on the rear shock tonight. I made a quick and dirty mount out of a piece of small tubing and a long bolt and tacked it to the top of the swingarm. Then tried the rear shock from the original 110 cc ATV donor.

I laid out some tubing to hold the seat, and took the frame off the concrete block to see the ride height....

(Fast forward to skip the first load test because the shock was too wimpy and the top hoop caved in because of incomplete tack welds)

Knowing I need a stronger shock, I went for the one with the largest diameter coil. It feels great !

With the shock mounted, I stacked some scraps on the swingarm to help determine the motor plate height.

Note: before I installed the shock I did a full bump test to make sure the motor would not hit the top shock mount. Also did a full droop, and that was not an issue either.

I just eyeballed the motor plate to make the engine about level when I sit in it.

...needs to have about 3 inches above the swingarm on the front and about two inches above the carrier mounting brackets on the back.

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Thinking about the chain adjustment and the possibility of using bolts in the back to raise the rear of the motor because the driven sprocket of the TAV is in a good place for raising to tighten the chain.

 

[gegcorp2012]

Here's what I didn't finish tonight...

I chopped up one of the scrap bed rails from the recycler to make my motor mount and floor supports for the seat. See the tan colored angle pieces in the photos.

The motor mount is hinged on the front so the chain tension can be adjusted by raising the rear of the motor.

I plan to add two bolts on the back of the motor plate and make them captive or use some allthread and lock nuts to jack the motor up. I am still figuring out this part, as the pieces are being made. First I have to get the motor in place and check the chain alignment, etc.

Also checking the rear brake caliper and mounting bolts.

I smoked the drill bit in the process of drilling the seat brackets, and called it a night because it was screeching so loud.

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[gegcorp2012]

So the rear swingarm is centered between the wheels and on the kart frame, but the engine needs to be slightly offset to the right so the driven sprocket of the TAV will line up with the axle sprocket.

Motor attached to the angle iron motor plate.

This shot shows the front and rear mounts on the swingarm before installation. The front mount is not in the final position, so it looks pretty crooked in these two photos. .

Front mount is angle iron with a piece of tubing welded across the top. The motor plate is drilled so this front mount is a pivot.

Rear mount is 1" angle iron that has been drilled for the adjusters made with a bolt and washer welded near the top so the bolt is held captive but can still be turned. The top nut acts as a lock nut and the bottom nut will be welded to the carrier mount bracket. This part will be installed with the adjusting bolts in the vertical direction.

Everything tacked into place with chain on and adjusted.

So this took me longer than making a traditional slotted motor plate, but the vertical adjusters seem to work really well at raising the motor to take the slack out of the chain.

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[gegcorp2012]

Moving to the front, I have a puzzle to solve with the steering rods. When the front control arms and steering was on the ATV, the steering rod ends just bolted onto the bottom of the steering shaft where there is a butterfly shaped bracket with two holes. Only one hole is visible in the photo below.

I added 12" in between the control arms to make a foot well for the cart, and now I need to add that to the steering linkage. The easiest way would be to just extend the steering rods 6" on each side, but that might add some bump steer. Think that would be critical on a yard kart ?

I am planning to drive it as hard as I can so I am willing to upgrade to a rack and pinion setup if I can find a rack that is about 10"-12" long.

>> Do you know what kind of vehicle may have a rack about that size ? I started looking but have not found any used parts that would work yet.


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[gegcorp2012]

Made some brackets for the front shock mounts today.

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[gegcorp2012]

I put in a day's worth of teardown, cutting, welding and wire brushing over 100 welds.

So I had an issue in the front right corner that bugged me enough to cut the welds and re-do them after tweaking that top tube a bit. I didn't want to weld on the top shock mounts until it was right, so here goes...

I had to drop the top tube down about 1/2" and make adjustments to the angle iron tabs for the front suspension.

Flipped the chassis over and laid down some flat tubing so I could put pressure on the frame tubes to complete the welds and straighten the front area of that upper hoop.

Building in a jig would prevent this type of rework... just sayin'.

Using flux core 030 wire because my welder rollers slip on the smaller diameter 023 wire.

Aaaahhh, that's better.

I am pretty sure I used at least 3 pounds of wire, because I went through a couple of partially used spools and into a brand new third one.

Lesson learned: I need to invest a few hours to finish my tubing bender before making the roll bar hoops so I won't have to spend extra time cutting and welding any more bends like I did on the frame... lots of welds.

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[gegcorp2012]

I put on the floor pan and started on the steering shaft.

The rusty piece of 1x2 tubing is temporary, to hold the steering wheel at the desired height while I work in the upper mount.

I added a short piece of tubing to connect the two shock towers and that was a good place to hang the steering base plate.

Just a quick trial fit to see if the longer front and rear brake hoses will work. This also helps to see what I need to do to mount the master cylinder and pedals.

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[gegcorp2012]

Working on the brake pedal assembly.

I found this two plunger master cylinder on the interweb and thought it might be a good value. The plungers are adjustable, so the front brakes can be made to engage before the rear... The idea was to be able to hold the just enough pressure on the front brake to do burnouts, but I got to thinking if I wanted to do a "Starsky and Hutch" style slide, the front brakes would have to be totally locked up, so I am not sure this will be as fun to drive as having a truly split brake system.

Right off the bat, I'm not liking the shape of the pedals because they have that goose neck bend that makes them short. These need a trip to the vice for some tweaking.

To put it into perspectve, the pedals dont really stand out now, but will be more noitcible after painting the chassis and floor. The upper steering column mount is some curved metal tubing I got from one of the scrap yard trips.

The master cylinder has 4 ports... one port for each brake line and an extra port for a pressure switch. Of course they sent me a brake light switch that has the wrong thread pitch, so now I have a return part situation or need to find a suitable plug and a longer rear brake hose to finish the brakes if I go this way (strike one).

So I made a mounting bracket to mount to the pipe between the shock towers. This would require a longer rear brake hose (strike 2). Here is the top view with the M/C on the mounting bracket in the most natural location. I am re-using the ATV brake line splitter and can move the lines around for neatness sake.

Also noticed the steering link highlighted in red will be rising up when making a right turn, and may interfere with the brake rod, depending on the final pedal config.

So I will be taking a look at using a front/rear split system to see if I can get that to work with the parts I have on hand...

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[gegcorp2012]

Ok, so an interesting day today.... I was rummaging through my ATV parts bin to look for that TaoTao 110 rear brake pedal and cylinder, and actually found it. The rear brake (foot operated) is the wrong shape and the cylinder wants to be mounted vertical, and it has no reservoir and a broken cap where the fluid is supposed to be sealed in. That is kind of a bust, but in less than 10 minutes, I had some answers on what I want to do with the rear brake.

I ordered a longer hose for now, but I do have a new, remote reservoir rear brake cylinder that would work perfectly in a horizontal mount like I would make for a drift brake kind of installation. I guess that could be a stage 2 mod after I get it all together and running.

Lots of detail follows but here is a photo to keep your interest.

...and finally, a breakthrough on the rear axle/rear tire situation. On week 2 of my build, i bought a scrappy Yamaha 350 warrior frame and tire set. I was trying to see if the rear tires could be adapted to fit on the Peace Sports 3 lug rear hubs. No, that wont work at all.

So it was pretty frustrating because the rear tires I have been trying to use are just not working out. The other day I stepped on one of the valve stems and caused a leak in the left rear, and I had damaged the bead on the right rear while installing a tube, so that one is way out of round and dangerous to consider using it. Also the rear axle needs to be a foot wider since I added that much space to the front end with the kart frame.

Then I checked the Yamaha axle again... it's wide enough and has great wheels but would require lots of rework to use, but the hubs.. hmmm the hubs have 24 splines.

Oh, shoot my kart axle is 23 splines.

Heres a comparison of the tires and hubs I have to work with...

I found the Taotao 110 rim had a 23 spline hub with a 110x4 bolt pattern (only have one of them though) and I verified that 23 spline hub fits the axle I am using in the kart. The Yamaha rims like the 110x4 bolt pattern but has a 24 spline hub.... so I went online and found me a pair of matched 23 spline 110x4 hubs and a couple of 2" spacers and think the rear end will be within a fraction of an inch once I get these hubs and spacers on the axle and the Yamaha rims and tires on my kart.

Oh, happy day !

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[JTSpeedDemon]

Ouch, that's a bad day!

 

[gegcorp2012]

Seroiusly, I was happy to get through all that and to find the rims had favorable backspacing. I re-measured and need 3" on each side (measure twice and buy once, right?)

Here's how it should look, but it's still on a block. I have a set of spacers on order.

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[gegcorp2012]

I decided to add a muffler to my header pipe so I will be able to ride without having my neighbors call the Police on me.

I made a couple of cuts and changed the bend slightly so it is more centered.

When I was welding it back together, my welder started giving me problems again.

The welder motor plate had cracked up again and that allows enough flex so the wire feed rollers were slipping badly again.

I took it all apart and found some specialty tips for my soldering iron and decided to try to re-assembled the pieces like I did a few weeks ago, but using the "paddle tip" ...

Actually, I added lots of material around the 3 holes where the motor mounts to the plastic plate in hopes that it will be stronger now. Having a mig welder that spits the wire reliably makes a big difference in keeping the heat where it needs to be for good welds.

Here is some work on the foot pedals...

In this photo, the master cylinder in its final mounting location so it is removable and yet clears the steering rods. I will make the master cylinder push rod once I get the pedal assembly mounted to the floor.

The extra 2 inches on the pedals makes them taller for my size 12.

Also tried a new flap disk to see how it will look after grinding some of the welds I made for the bends.


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[gegcorp2012]

Re-design time....
I have been waiting for 3 weeks on the rear axle hubs and in the mean time I found that they would not be the perfect solution for the build, so it's time to re-design the rear swingarm.

I'm going to use the Yamaha 350 rear carrier, axle and tires I bought in week 2 of my build. It's funny to note that I bought those parts to use on build and convinced myself not to use the entire monoshock assembly it because I would need a bigger motor.

Now I think that needing a bigger motor is a better problem to have than trying to make the 110 class rear axle wider using these spacers.

So I was planning to add (4) 1-1/2" aluminum spacers (2 on each side), they have a 110mm lug spacing, and that is an exact fit for the 23 spline 110 class ATV hub. After getting these parts, I could see that I would also need some machine work (- -$) to make a lip to help keep everything centered and then researched the lug spacing for the Yamaha rims and found they are 115mm. That would require me to drill out the lug holes on the rims or machine new holes on 115mm centers (- -$ ), so that is too many minuses for this design attempt.

Here is a comparison of the 110 ATV carrier/axle and the 350 ATV carrier/axle

The new plan is to fab another swingarm and make sure I can sit a larger motor in the same space where the 212 will be mounted...

 

[gegcorp2012]

Here is some "sawz-all" action on the Yamaha Warrior monoshock rear clip.

Measured for the cuts and decided the kart frame would be close enough to accept the entire monoshock assembly as a transplant.

Used some tie wraps and a piece of wood to hold it in place for a trial fit on the kart frame...

This is as close as I could get on my 30 minute break, but it appears the operation will be a success once I take out the mount structure for the previous swingarm.

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[JTSpeedDemon]

Do you know how to upload pictures as thumbnails? Makes the thread more space efficient and easier on the eyes, not to mention that we can open them up bigger if desired still.

 

[gegcorp2012]

Hi JTSD,

No, have not tried the uploads as a thumbnail. I typically use my phone to enter the posts, and all I get is a grey box in the lower left corner that has a [+] sign for Photos,Files.

After selecting the files I hit the > in the upper right corner to send.

Is the image thumbnail a <html edit> kind of thing or something you have when using the computer with a browser ?

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[JTSpeedDemon]

If you go to the Quick Reply box at the bottom of the screen, and hit "Go Advanced", you will be directed to a large, well optioned workspace. After clicking on a paperclip icon, a little window will pop up to manage attachments. After uploading from your files they should show up as thumbnails.
Not sure how different the phone interface is.

 

[gegcorp2012]

HI JTSD,

I logged in today on a laptop computer to check out what you were describing.
Since I have not uploaded any of my files on the computer, there were no attachments there for me to manage.

When I view these images using the laptop, I can see the images have automatically been resized to 360x640.... that is a bit larger than a thumbnail, and should be more space efficient, making the pictures load quicker than their native size.

When I click on the bar at the top of the image, it re-sizes them when using the laptop, but I do not get that option on the phone.

Using the web browser on the computer, I can right click on the image and select "Inspect" (using Chrome) and it shows me HTML code for the page, highlighting the image size before clicking on the top bar:

Actually the image tag has an embedded function call named NcodeImageResizer.createOn(this) to switch the image sizes back and forth.
Before clicking on the bar...

<img src="https://uploads.tapatalk-cdn.com/20191001/7e2120fad1d41fceea361900f014d2c5.jpg" border="0" alt="" onload="NcodeImageResizer.createOn(this);" id="ncode_imageresizer_container_49" height="360" width="640" class="ncode_imageresizer_original">

After:

<img src="https://uploads.tapatalk-cdn.com/20191001/7e2120fad1d41fceea361900f014d2c5.jpg" border="0" alt="" onload="NcodeImageResizer.createOn(this);" id="ncode_imageresizer_container_49" height="459" width="816" class="ncode_imageresizer_original">

cool, huh?

 

[gegcorp2012]

Got the new rear end fitted and welded in. I scraped the paint and caked on dirt off and could finally read some details on the reserve canister that said Yamaha Monocross Suspension

It's overkill for a yard kart, but It fits well and has an adjustable shock for ride height and has the proper axle width for my build and I already tested the spring rate while it was on the ATV, so it should be fine, although is heavy enough to move the center of gravity back a foot or two.

Welding photos... hard to weld accurately with the phone up in the welding mask, but I tried one bead like this anyways...

Yucky smoke and splatter using flux cored wire.

You can see this bead needs more heat and wire up on the upper side to close all the way in. Easy to fix once I dropped the phone and went back over it with both hands on welding gun for steadiness.

Also started mods on a new sprocket and found that one of the carrier bearings was froze, so I will be replacing them both. Also got new brake pads.

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[gegcorp2012]

Here's some progress to get everything ground down, smoothed out and painted. I was thinking about silver/black and decided to start with everything black then do the tubes silver.

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