New Member-Muskin Dune Cat Project

#1
Hello All- I’m a brand new member on here. My buddy recently gave me (sold me really cheap) a Muskin Dune Cat go kart. I was stoked to get the thing running for my 9 year old son, and thought the thing looked like the coolest go kart I’d ever seen. I did a little Google research and came to realize (mostly from this site) that these carts are pretty rare and highly coveted. I’m not a go-kart or minibike enthusiast per-say, but I am pretty handy and this kind of project is right up my alley- plus I realized then that I had a responsibility to put this awesome little cart back into awesome condition – (rather than just the bare minimum to get the thing running and bounce around the dirt roads as was most often the case when my dad would bring home a go-kart when I was a kid)

That was 16 days ago and this project is coming along real quick- I wanted to put some pictures up to show Keith (the guy who sold it to me) and also so my dad could see them. My thought was that this forum would be best place to photo-document my restoration project as others here should appreciate it. For the purists here, as I assume there are, this Dune Cat arrived to me in other than stock condition. The “Jack axle” (is this right?) drive system had been removed, and replaced with a simple chain drive sprocket, mechanical caliper brake, and a 5 horse B&S, that I’m not sure had ever been hooked up.

Had I had a more “stock original” copy to begin with, I may have been more inclined to try and put this Dune Cat back to original- since my kart was already drastically altered, I decided to go in the opposite direction, while still keeping intact the simple elegance that makes the Dune Cat so cool.

When I was a kid, I had a wide variety of (amazing) near-death experiences on go karts, including taking one through a barbed-wire fence at full speed. I decided almost immediately that I was going to put a roll cage and seat belt into this cart before I sent my kid off in it. I think I was able to do that without detracting from the cool “Dune-Cat-ness” of the kart, but you’ll be the judges on that.

Anyway I’ll end this post with a few pictures I took of the Dune Cat on Day 1 (August 26, 2012). More to come on this project if I hear back any interest.




I believe that is the stock original green paint with white penstripes- I understand that it was only in Blue, and then later in green and red, can anyone tell me if this helps put a date of manufacture for this kart?



4 different tires, and maybe you can notice the extensive fiberglass damage in front.




FYI- the guy who sold it to me told me that the thing has sat outside without starting for over 10 years.






engine was not bolted down and did not have a clutch, I'm not sure if it had ever been running in this bike-



Cat sticker on back, I'm going to have my fiance replicate the original stickers for me-
 
#2
Day Two:

The boy and I started taking it apart, cleaning it up and doing BDA (battle damage assessment).












I had decided to set the engine aside, and take it to my Dad’s as he is a master with a small motor- On a whim I decided to spray a little starting fluid in the air cleaner and pull the cord- the damn thing started up and almost ran off of the table! I changed the oil, cleaned out and replaced the 10-year old gasoline, new spark plug and air filter from the LHS- and a little wire brush and silver spray paint and this thing is screaming like it’s brand new- GOTTA LOVE BRIGGS AND STRATTON!









I bolted the motor to a 2x6 that I could stand on to test run it. I assume that's SOP around here, but seemed like a cool trick to me discovering it for for myself.

I also took the front steering components (which I apologize for not knowing all the proper names of) to the wire wheel and polished then to bare metal and put them in bare metal primer.



 

buckeye

Well-Known Member
#3
Welcome to OldMiniBikes. That is quite the project you have.
Many of us would love to find a project as fine as that.
Plus,you are doing it with your son.
Don't hesitate to ask questions. Folks gladly help around here. Expect a few good natured jabs,as that comes with the fun that is had around here.
Keep the pics comming. Look forward to seeing what ya do with it.
 
#4
DAY THREE:

Had the boy scrape the old stickers and pin stripes- and do some preliminary sanding and chipping on the fiberglass body.

I had bought some 1” pipe, and cut and ground a piece to shore up the front of the frame as I’m inevitable going to cut the front end off of this frame.

I then went to work on building a new front “bumper” that the roll cage will attach to and also a real bumper in front. Some of these pictures show well the fiberglass damage in the front, and I want the new cart to be better protected from such damage in the future. I have had this Harbor Freight pipe bender sitting in my shop forever and never used it- tons of fun, I’m looking forward to a new project (excuse) to use it to build something cool.

I really wanted to minimize the modification to the existing kart- especially the fiberglass. I think I accomplished this- the only modification to the fiberglass is the two small cut-outs right in front where the front of the frame now extends past the front of the shell. (as seen later)









More later.
 
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#5
Stupid photobucket, I guess these pics are too big and it's having trouble, I may have to edit posts with smaller images. Am I the only one who can't see my last images??
 
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#9
DAY FOUR:

Had the day off and could work on the cart all day. I cleaned, sand-blasted, and sanded the cart- then I coated it in a bare-metal primer. FYI- The stuff works good for protecting metal from rust, but it coats on thick and is soft like hardened marshmallow- it makes the paint when you’re done easy to scratch, and I’d suggest avoiding it and just using a basic (cheaper) automotive primer.











I finished fabricating and welding on my front frame assembly, There’s about 9 inches of solid steel rod at the union of the old and new tubing that is tight enough that it had to be hammer driven, all told as good of a welded junction as you could hope for.



I also bent, welded and mounted my front bumper on.



 
#10
DAY 5: (another day off from work)

Made my cutouts in the fiberglass to accommodate the full frame- pictures indicate the task ahead in repairing the fiberglass. I had marked around all the cracks with a sharpie- the blue masking tape holds on a piece of the fiberglass that had fallen off once I made my cut-outs. Major fiberglass repairs ahead.








I set to work on the roll cage, was able to get the broad strokes accomplished with a late night.











 
#11
DAY 6:
I finished the roll cage by adding some cross members (keeping the dune cat tail angles in the back) and put the rest of the bare metal in primer- ran out of paint so the cart ended up in about 4-5 different colors of primer and matt paint. There is a point to having the drop bar come down behind the driver as will come appearent later.





NOW- here’s something I thought you guys here on oldminibikes would appreciate. It’s obvious to me that this 5hp B&S was pulled off of something other than a go cart. For one, The exhaust vents directly onto my fiberglass body, which is unacceptable. I had recently bought a bunch of stainless steel drink containers at a local thrift store, I wasn’t sure what I was ever going to do with them, but I knew that they would come in handy someday.

Turns out, the bottles had the exact correct size mouth opening and rolled rim to make a perfect muffler for this motor. I cut out some plate aluminum (road sign) to fit exactly around the bottle neck, and then split it in half- I wasn’t sure if the four bolts would hold the the two split locking plates, but it is tight, and strong, and you can lift the entire motor by the muffler without the slightest hint of movement- I’m not sure how it’s going to hold up to heat, as the aluminum expands differently then the steel, but after studying the existing stock exhaust diverter, it’s got to work better than stock under any circumstances. I drilled lots of holes in the end as pretty as I could- I was worried that I wouldn’t have enough surface area of orifice (big enough holes), but the new muffler has much more orifice than the stock so it should be fine. I’ve since found a very similar looking muffler online for about 60-70 bucks. Anyway, it solved a problem, time will tell if it creates another one, it looks cool as hell at least. I'm very curious as to how it's going to sound but resisting the temtation to run the motor again until I have it mounted to something more soldi than a 2x6.








 
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#12
Day 9: Labor day Holiday. (day 7-8 didn’t provide a chance to accomplish anything beyond looking and measuring and thinking and planning)

Fiberglass day. I know that it’s probably insulting to many here to have some new guy come around and try to start explaining how to do things. I expect there are eons of experience among the master fabricators here, but I’m betting there are also others looking through these forums thinking “great, but HOW did you do it?” I’m usually in this latter group and that’s who this first image is aimed at because I wish the guy who tried to fix the fiberglass on my Dune Cat some number of years ago had been given some kind of direction before he made such a mess of the job.




I included this image because I wanted to turn some of you folks onto this Parafilm. It’s pretty readily available and I wouldn’t live without it in my shop. It’s basically a wax film tape that can be stretched out very thin or built up in several layers. ( I often chew it like gum) I find it often superior to masking tape, mold release (or resin molds) and a dozen other things. I use it for glass bedding rifles, sealing threads, masking threads, masking holes, masking guns, sealing containers (which is what it is designed for as used in laboratories)- basically a gazillion things.





I’ll spare you guys a ton of images of the fiberglass work but here are a few to show the scope of the job. Some are out of sequence as I found some new rot a few days later where the body rides on the frame, (where your foot would rest when driving the cart. I also didn’t like the worn-out look around the slots of the foot pedals and refinished the slots with fiber-resin to give them a more clean and uniform look. I will say this, the body is now solid and stronger than they day it was made. Still lots of spots, specks, dimples, pin holes, scratches, etc. to be tended to later- but the major repair work is done.














 
#14
Day 12: (Day 10-11 no chance to get into shop)

TIRES-
Spent about 4 hours at the tire shop while they had hell changing out the junk tires for a nice matching set that my buddy had thrown in with the cart (remind me to do something nice for that guy-WOW) This cart has 8” rims, the backs are 22x11x8 and the fronts had on 18x8.5x8- the new set is 22x11x8 in the back, and 20x7x8 in the front. The back rims are split rims, and the tires say “no split rims” on the side of them, but they were able to salvage the inner tubes and get them holding air- the new fronts are a little narrow for the rims, but they were able to get them sealed using bead sealer. My tire guy didn’t charge me a dime as I spend a lot of money there on my work truck and I recently had some issues with some work he did on my personal truck (we both kind of knew I had a freebie coming).

The boy and I sanded our butts off, and I got them painted up in the wee hours. Figured I’d throw in this image as I thought the (stretchy type) trash bags where a nice trick worth sharing for painting rims- pull the bags on, cut out around the rims, mask around, tuck the tape into the bead- works great, super quick, and cheap.











I also masked my sprocket, painted around there, then in the morning, mounted the sprocket with hard chrome bolts, and then masked the whole thing off for tomorrows paint day.




I also discovered that the steering arms where too long- so the the dadgum wheels where going to be "kinder wall-eyed"- so I built some new shorter ones- (welded these bolts to these rods)



 

buckeye

Well-Known Member
#16
Sure are.
And some great tips as well.
Hope ya stick around. Good addition to OldMiniBikes.
I love the plastic bag trick. And the water bottle trick. :thumbsup:
 
#17
Day 13- Paint day

Now I do realize that seeing this old-school, vintage, retro, Dune Cat with a roll cage and painted in bright orange is likely to make a lot of folks on here want to vomit in disgust. The first day or so I spent a good deal of time thinking about what color to paint this thing (which is probably the funnest part of a project like this). I thought that If I was going to send my kid out in the woods in a small vehicle, I’d want him to be as highly visible to other drivers/riders (and me) as possible. I was thinking Blaze Orange, as I am a Game Warden and Hunter Ed instructor and have come to be a real believer and fan of that color- In the hunting areas here where we require hunters to wear Blaze Orange (military land), I love being able to see folks (up to miles away) out in the desert or woods- and I thought this same concept would be a good idea for my kid’s go cart. I soon realized that ALLIS CHALMERS ORANGE is pretty close (close enough) to Blaze Orange and is easy to find- 5 years from now I’ll be able to buy a can of Allis Chalmers spray paint and touch this thing up, which is a very nice feature. SO it’s Allis Chalmers, I still have not set in stone my plans for painting the fiberglass body, it may be AC Orange, Blaze Orange, or some other direction.

















It's come a long ways in a short time- I do kinda have an addictive personality :eek:ut:
 
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#18
Thanks guys for the feedback- I am kind of addicted to This OldMiniBikes stuff after getting a taste- I would love to do another Dune Cat or other cool go cart- so if anyone has one they would be willing to part with let me know- I won't be doing two-wheeled stuff- My best buddy in 4th grade got killed in front of my house on his little YZ-80 dirt bike (head on with a pickup) so I'm not a motorcycle fan and that probably explains my compulsion to make this thing as safe for my kid as possible.
 
#19
Day 15
I mounted a new mechanical brake- I chose to go with this cheapy looking little caliper brake because that was what was on the bike when I got it. It was broken (the original) which doesn’t surprise me, but was easy to mount as someone else had already done the work to weld a mount on, so it was a simple bolt on, and the linkage fit perfectly and the brake functions when the pedal is pushed. We’ll see how It does in real life.



 
#20
Day 16:

Next I’ve been working on the seat. I just purchased (E-bay) two yards of marine vinyl upholstery fabric- bright orange. I cut a paper template, and then a plywood base, and a memory foam pillow for the butt seat. Pretty simple.




Now I wanted to have a nice looking proper back seat pad. By my thinking and skill set, this would require a stiff board or plate that is exactly the same curve as the Dune Cat body. Here are a few pics showing how I accomplished that.

I set the body up so that the seat back was about level to the ground and covered it in plastic film. From there I could lay fiberglass (2 layers of fiberglass cloth) to make a ridged form with the exact shape of the body’s seat back.





I then used my paper template to cut out a thin sheet of plywood. I cut this plywood into vertical strips, and then- using a whole lot of F-glass resin, set these strips in the form. I had to put a bunch of steel and lead weight on the top of the boards while the resin set up to keep them held down as they where pretty warpy (old junk bard) especially after they started soaking up resin. Once set, I added a layer of F-glass matt, and another layer of F-glass cloth on top, and Ska-dush! I’ve got a rigid curved backing board on which to attach the foam pad and vinyl of a seatback.
Ultimately, this seat back will be fitted with two bolts that will extend through the body (seat back) and be bolted to the body.










 
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