Yerf dog 3205? Maybe

CS#24

New member
Messages
8
Reaction score
1
First time posting thanks in advance for any help. First time build. Bought this and it has predator 420 on it. Guy I bought it from said bought brand new motor but it didn’t come with clutch. He bought one, installed it got on and went 5 feet and smoke coming from clutch. Frustrated he pushed it in garage. Later his big pressure washer recoil starter broke so he robbed the pull starter off engine. Also robbed battery for electric start to use on lawn mower. First, is this 3205? Second, where did he go wrong on clutch so I do not make same mistake. And lastly, I got a recoil starter and had battery that would work and engine fired immediately with no smoke and idle great. What would yall recommend I buy clutch wise and kart seems to be all original with exception of motor. Sprocket appears to be original 60 tooth. Rear tires 20 inch. hows this ole girl gonna run? Thanks again1630342367270.jpeg
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
Pic looks like it could be any of the 3203, 3205, 3208 of the pics in link below if you ignore the paint schemes. There's only very slight differences in their measurements, but you might figure it out that way. All 3 of those come from the factory with 6.5hp. Tecumseh engines (with torque converters/CVT's, ie; a driver clutch and driven pulley), so I'd say a 13hp. 420cc driving the stock sprocket would make it run like a raped ape.
Yerf-Dog Go Karts
If you go with a TC/CVT it would need to be a 40 series, not the 30 series. If you go with a clutch, just get a heavy duty one that's more expensive than the cheapest. Folks like Hilliard clutches a lot.
No matter which way you go, the output sprocket has to match the existing axle sprocket, hopefully a #40 or #41 (1/2" width). #35 (3/8" width) is not as heavy duty.
 

CS#24

New member
Messages
8
Reaction score
1
Thank you for advice that helps. I read where the larger tires and heavy kart can be death to clutches. I’ve ordered a 10T clutch 41p and my chain is a 40. axle sproket is 60T and I’ve replaced rear 20x10 tires with 16x7. Will this combo work. clutch was rated to up to 13 ph and my 420 predator is box stock. Thanks again this forum is amazing.
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
Check link below. The chart there explains different chain and sprocket sizes, and you'll see the problem with 1/2" sizes #40, #41, and #420.
The roller width on #40 is 1/16" wider than #41 and #420. Then, #41 pin diameter is 1/32" smaller than #40 and #420.
Really though, the only important part of that is the #40 roller width being wider. That means all 3 sizes of SPROCKETS can be used with a #40 CHAIN. However, a #40 SPROCKET is too wide for use in a #41 or #420 CHAIN.
Chain for Go Kart, Mini Bike | GoKarts USA®
...............Reducing your tire diameter that 4" you did will greatly increase your low end torque. Might even be able to doughnut that thing with that 420cc pouring 13hp. to it. Clutch should survive fine as long as you always run at least a few mph after starting off. Clutch slips until then, need to keep it fully engaged.
 

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
Thank you for advice that helps. I read where the larger tires and heavy kart can be death to clutches. I’ve ordered a 10T clutch 41p and my chain is a 40. axle sproket is 60T and I’ve replaced rear 20x10 tires with 16x7. Will this combo work. clutch was rated to up to 13 ph and my 420 predator is box stock. Thanks again this forum is amazing.
You're only option for a clutch system that will last is going to be a 40 series.. having similar nightmares now. also that thing came with a diff motor and had a factory jackshaft and torque converter.
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
Yerf-Dog 3205 is advertised with a 6.5hp. Tecumseh running a 30 series CVT at 308 lbs. That 13hp. 420cc replacing the 6.5hp. makes me think it would skedaddle pretty good even with the extra 40 lbs. and without a CVT.
CS, if you did decide to get a CVT for more low end power and fun, it has to be a 40 series (30 series isn't rated beyond 8hp.).
Read the text info on this link............Comet Drive Belts | Comet Torque Converter Belts | Go Kart Belts (gokartsupply.com)
Here's (3) 40 series CVT's for 1" shafts, and driven jackshafts 5/8", 3/4", 7/8", all with backplates, and for just under $100.
Amazon.com: Jeremywell 40 Series Torque Converter Kit Clutch Pulley 1" Driver 5/8" Driven 8 to16HP Belt replace Comet 40D Series Torq-A-Verter models 209133A, 209133, 209139A, 209139, 209151A, 209151, Manco 2432 : Automotive
Amazon.com: Jeremywell 40 Series Torque Converter Kit Clutch Pulley 1" Driver 3/4" Driven 8 to 16HP Belt replaces Comet 40D Series Torq-A-Verter models 209133A, 209133, 209139A, 209139, 209151A and Manco 2432 : Automotive
Amazon.com: Jeremywell 40 Series Torque Converter Kit Clutch Pulley 1" Driver 7/8" Driven 8 to 16HP Belt replaces Comet 40D Series Torq-A-Verter models 209133A 209133 209139A 209139 209151A 209151 and Manco 2432 : Automotive
......................or you could get a genuine Comet 40 series from GoPowerSports for $350.
In any event, the TC takes care of the clutch cost, the 1" driver is the clutch, no need to buy a clutch.
 

CS#24

New member
Messages
8
Reaction score
1
Ok y’all talked me into 40 series torque converter. I’ve been watching videos and reading what I can find on install. And I know this will be dumbest question you’ve had about these, but where does the chain connect? ive watched several videos and i get the two pulley install and belt also, but what turns the rear axle?
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
If you're looking at the TC/CVT (Torque Converter /aka/ Constant Variable Transmission) from the side, looking at the driver clutch on your left and the driven pulley on your right, the axle for the driven pulley on your right extends right through the backplate, sticking out the back side of it a couple of inches. The sprocket is mounted on that shaft between the driven pulley and the backplate, a very close space barely wide enough.
And OOPS, sorry, I lied about the links above having backplates, they don't, I was confused, still am in fact. Just type "gokart 40 series torque converter" in your search engine, you'll see some with a backplate.
Attaching a pic of my 30 series that shows how my chain comes out from between driven and backplate.
 

Attachments

  • 100_0166.JPG
    100_0166.JPG
    2.4 MB · Views: 2

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
Ok y’all talked me into 40 series torque converter. I’ve been watching videos and reading what I can find on install. And I know this will be dumbest question you’ve had about these, but where does the chain connect? ive watched several videos and i get the two pulley install and belt also, but what turns the rear axle?
Depends on your setup. some CVT's come with a backplate assmembly and work well as a kit. If you're like me and always customizing, nothing fits like its supposed to ever.. I had to fab a separate jackshaft bc the backplate wouldnt clear my engine head and I was limited for space elsewhere.
 

CS#24

New member
Messages
8
Reaction score
1
Ok got 40 series converter kit from go power sports.com today. Was watching YouTube video from guy Kevin Robinson, literally doing exactly what he did, same kit same motor. I used same holes he did to mount plate, step one, and my plate touches the head before bolts will tighten. there is a thin aluminum shield there, but he didn’t remove it, I can see it in video. What am I doing incorrect.
 

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
Ok got 40 series converter kit from go power sports.com today. Was watching YouTube video from guy Kevin Robinson, literally doing exactly what he did, same kit same motor. I used same holes he did to mount plate, step one, and my plate touches the head before bolts will tighten. there is a thin aluminum shield there, but he didn’t remove it, I can see it in video. What am I doing incorrect.
Post some pics.. I know with my Duromax 440cc the mounting plate would not clear my head either so I ended up fabricating a custom jackshaft for it. Things get a little tricky when you have to start offsetting things to work together. If you cant get it all to line up and fastened correctly, something may need to be further modified.. welcome to go karts!
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
The "fab it as you need it" part of building is the most fun part for me, try to enjoy it. Take a good look at your backplate and decide what areas of it are important. Certainly the 4 holes you bolt it to the engine with. Certainly the bearings boss for the driven pulley. Certainly enough metal between the bolt-up and the bearings boss for it to be strong. You can cut, slice, whatever away from the backplate with a metal cutoff wheel in a grinder to clear obstacles, as long as you leave what's truly important.
 
Last edited:

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
The "fab it as you need it" part of building is the most fun part for me, try to enjoy it. Take a good look at your backplate and decide what areas of it are important. Certainly the 4 holes you bolt it to the engine with. Certainly the bearings boss for the driven pulley. Certainly enough metal between the bolt-up and the bearings boss for it to be strong. You can cut, slice, whatever away from the backplate with a metal cutoff wheel in a grinder to clear obstacles, as long as you leave what's truly important.
What he said:wai:
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
You can also clock the mounting plate in different positions.
Oops! Why did I not say that? Afftah awl, I kin spellz goofee azz well azz ack lyke itt!
So you mounted your backplate using the same holes as in the video, and something's in your way preventing the backplate from pulling in flush to the case. Denny's saying there's bunches of holes in that backplate that will allow you to rotate it around (like clock hands) to different positions and still have 4 holes that'll line up for bolting it to the case. I'll attach 2 pics of the same 30 series CVT mounted in a position a little downhill from horizontal (minibike) and in a vertical position (gokart). As Denny said, you can "clock" those things many ways, even straight forward if you want.
 

Attachments

  • IMG_20190818_162541.jpg
    IMG_20190818_162541.jpg
    2.9 MB · Views: 2
  • 100_0166.JPG
    100_0166.JPG
    2.4 MB · Views: 2

CS#24

New member
Messages
8
Reaction score
1
1631918558795.jpegyou guys are awesome thanks. Got her mounted flush and tight. Now…am I trying to align the valley between the two pulleys or the rear of the two pulleys? This looks good to me but would rather have experienced unput before moving on.
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
Okay, I'm confused again, don't know my proper spring colors. I know that the torque converter diagrams on this page...................
Comet Drive Belts | Comet Torque Converter Belts | Go Kart Belts (gokartsupply.com)....................show 40 series TC's with the moveable sheaves of the driver and driven being on the opposite sides of each other. I also know that doesn't sound right if it's on a backplate. This must be where the reverse direction spring comes into play. Yours is yellow, hope that's right. The thing is this..................
When rpm's wind up and the pulleys shift with the setup now this way, the belt's going to move toward the engine on the driver, and it's going to move away from the engine on the driven. That's going to have it running all side-a-wompus.
Isn't it??????? Somebody sound off here, I just got a hot spike through my skull. Ouch.
 
Top