Nope, you need 9 or more ... at least 3 each plus some projects in the wings ....

lol 2 buggies is enough work and maintenance for me.

No its not, it's just like a crack den except it's a buggy den.

Well, I've got this one, picked up an Odyssey, and still want to do an engine swap project.

That'll be my 3.


My PWC addiction is even worse. I think I have 6 of them...... :~

yeah, me too.

I'll do a top speed run with stock pulley, then another with the performance pulley.

NO other changes. So, we'll see if this thing really does do what it's claimed to do.


Thank J man

Victory and defeat all in 1 night.


My Victory was my reaching 40 MPH finally with this thing. (40.2 MPH to be exact according to my Garmin hand held GPS) With a 300' speed of 32.7 MPH

And now for my defeat.

Installed the KNM performance pulley from J man and only got a 39.4 MPH top sped run.

Noticed the kart was "creeping" at idle now. (that's odd)

Getting some weird clunking and jumping coming from the back end at take off under hard acceleration tests. (not too sure what's going on here as it's dark and I can't see a thing)

Tore it back down to find I stripped the clutch nut (big flat one) that holds the big spring in. So the clutch was pressed against the bell and not allowing the belt to disengage fully. Causing it creep at idle.

I was also having issues of getting the gearbox out of reverse. Hopefully the stripped out nut was the cause of that too.

I have no idea when the nut popped off the threads, So I'm hoping it was during my WOT run and is the cause of the lost top speed.

But, ending on a good note though....

My 300' test after my top speed run was a success with the performance pulley installed though. 33.6 MPH (that's almost 1 MPH faster than my best run with the stock pulley)

And who knows if the stripped nut was an issue?

I'll have to install the new nut and retry the top speed and 300' tests again. We'll see what this pulley does.


On a side note, I'm really curious to see what the A11 cam would do in this set up now. I REALLY liked it with m 58.5mm kit. And now with the 31T rear sprocket, Tom's American made valve springs and stock CDI, I'm not too afraid of over revving it now.

Hopefully u work it out, what cam r u using now ??

good to hear on the success, now i gotta pass along a smacka-u-upsida-da-head award and yet again make the comment of "just say no to impacts!" make a proper spanner tool for the clutch and variator and use a breaker bar ... :~)

I use the 1/2" impact on the clutch torque spring nut. Just turn the gun down a bit and don't overdue it. The other nut for both variator and clutch bell I use a 3/8" impact.

A 12 now

I know. but it's so much easier.... :banghead:

I knew I fudged it up when I did it. I'm always bad for over-torquing stuff. Even by hand. :cussing:

I'm sure with the a 11 u will gain another 1mph on top end, I hand start the thread on that clutch nut then use 1/2 impact.

Me too. Just went a little more than normal this time. :(

Man, aint that the way it always goes?

Waiting for a stupid $3 part so I can do a performance part comparison test run, and it dumps 6" of snow on the ground.

Who knows when it'll be before I can get a top speed run in now..... :(

man that sticks, Im trying to make time to work on both my buggies and it got cold quick here but no snow yet.

We only got to 36 degrees today and next week there calling for a couple days high 29 degrees. Normal this time a year is 65 for the high. Now they are saying a possible 1" snow Sunday into Monday. Better stock up on the fuel oil, wood, gas, coal, or cow dung cause it's going to be a long cold winter this year.

its 36* here now.

Only 45 degrees here

Whopping 36* here. Guess what arrived in the mail today????


Geeez........

Um a new clutch nut lol. I have like 3 of those nuts with 2 buggy u never know

Yep, I now have 2 of them "in stock".

there u go smart man

Well I went and braved the elements just for you guys.

Gained absolutely nothing. Exact same top speed as with stock pulley. 40.2 MPH

Funny how it didn't move any. The exact same speed?

It didn't sound nearly as wound up as before. So I thought I might have gained a bit more, but no....

On a side note though, I'll have to check my 300' times. (made my top speed run and put it away before the cops showed up) I have a feeling my acceleration may have improved with it. It feels like it takes off better. I just need to prove it now.

huh im surprised ? I figured u would have gained 2mph on top end with it because it does ride higher

Yeah, me too. Thought I would have gained a little.

In all honesty, I actually ran a bit farther on that run than my original base run.

try the setup u have with a 16 or 17 gram slider, then try the a-11 cam

Just might do that.....

Did u get any results with the pulley in the 300 mark?

Haven't retested it yet.

First attempt, yes. (while flat nut was stripped)

Haven't ran that test again, yet. I ran past a guy walking his dog on my top speed run and figured I better put it away just in case the cops came. ;)

What's ur goal for top speed ?

As fast as possible......


Really wanted to get to 40. Now that I've reached that goal, whatever it comes out to be.

I'm just confused by all the other (heavier) 150 carts that have higher top speeds with less mods than I. I always wonder what is so different on those.

Hell, even Metalstudman posted he reached 40 with his stock Yerf.

I remember metal studman changing his gearing to get that fast, 40mph is nice espically if ur in trails! I bet with your setup though power is pretty good threw out, his im sure was a slug on the start

Really? He changed his gearing? I'll have to do some research on that one.

Yeah, take off is good on this kart now. (always took off pretty good once i started modifying it though)

Had the G/F in the Yerf and I was on a Yamaha Moto4 200 ATV and raced from a stop. She smoked me in the 300' race. Prob a length and a half.

1.yes if I remember correctly he changed his gearing

2. yeah the yerf takes off nicely since its light for a buggy

3. that race has to make u happy then the hard work paid off :) take a video if u can ?

hey xlint look what I found

http://www.youtube.com/watch?v=HU7hCoCMAjk

he says he did gearing change, with intake and exhaust, so I wonder if he changed the internal gearing?

Interesting..... Thanks for the link.

He does mention gear change, but only specifies sprockets. It's been so long, i don't remember what the stock yerf sprocket tooth count is. I know 31 on the axle is normal.

31 tooth is stock for. Axle sprocket on yerf

metal's build and mod threads should be on the site here ... same user name as his youtube ...

At the time, i believe the gear change metal mentions is from going to a taller tire and not from changing the sprocket.

I'll bet after watching the video the top speed was more likely low to mid 30's. The reason I say this is because when I used to use my GPS my speeds showed almost 10 mph more as compared to the dirt drags. Because GPS triangulates it takes about 3/4 to 1 mile for an accurate reading. But that all depends on how long their ride was.

yes gps isn't as accurate as an actual speedometer, il bet the same thing

I agree!! It doesn't matter what has been done to the motor. The tall gear ratio of a howett/yerf will run approximately 32 mph before the gearing tops out. That's the fact! Motor upgrades will help to get there easier/faster but that's all it will do. Think of a car stuck in first gear, how fast you going to get before the motor reaches a rpm limit.

surprised you guys don't remember metal posting this ... pretty sure he was definite on the upper 30s with it and also timed the distance ran at top speed.

The last I remember was he putting a 200cc shifter in his buggy and posting video, speed and times.

I'm going to agree there's no way it's going 40mph

After reading the comments below the video I would assume he is talking about final drive gears since below the video it said 16T small sprocket and 32 large which is stick for the Yerf. Back in 2004 and 2005 the carter buggy would definitely do 44mph top speed stock since they used 2:46 final gears, but they would not climb a mole hill for nothing. Everyone else were using the common 3:08 final gearing. Carter changed to the 3:08 in 2006 making it like the others 32mph stock.

Now you guys got me wondering.....

How do I calculate my final gearing?

13/40 internals (stock) with 16T and 31T sprockets.

Thanks

13 into 40 = 3:08,16 into 31 = 1:94. Add the 2 together for a 5:02 total ratio. Now if running different tires for every 1" larger deduct 1 tooth off large sprocket, 1" smaller add 1 tooth. This is how I have been told to figure total ratio.






;94:94

Not sure if it's add or multiply to get to the final ratio. Always thought it was multiply
either way, he was running 21s or 22s on the back instead of the stock 20s (which was the point of his "test") and if you look close, they're aired up pretty hard, likely putting them an inch oversize. This in turn puts his final sprocket gearing at 16-29 or 16-28. That change along with the uni air filter, and custom exhaust and carb rejet could put it into the upper 30s.

Oh yeah, sorry about that. 22" rears on mine

Yeah, after reading that, he isn't totally stock. So that makes me feel a little better about a "stock" Yerf doing 40.

Just an FYI my CVT is completely stock (except for the 14g sliders) as well as Metalstudman's.


Which brings me to this Q:

What is everyone else running for a variator and clutch set up in theirs?

I have no issues with the stock parts in mine, just wondering if there is a noticeable difference in the aftermarket parts?

I did read the Dr. Pulley is supposed to be the best variator (and HIT clutch too), but when I tried the variator on mine, it didn't do a dam bit of good. I think I may have actually lost a bit of speed. That's why I sold it and went back to stock.

. When more than one pair of gears are used together, that is called a Compound Gear Train. The gear ratios for each individual gear pair are multiplied together to compute the overall compound gear ratio
Using a basic stock Yerf with no reverse as example the basic math formula for getting overall ratio:
Trans gears- 13/40 13(A) , 40(B)
Axle gears 13/31 13(C), 31(D)
Divide A into B (40/13) = 3.08 [trans gear ratio] (E)
Divide C into D (31/13) = 2.38 [axle gears ratio] (F)
Multiply E and F (3.08x 2.38) = 7.33 ( overall drive ratio) (G)
This means for every complete rotation of the axle sprocket the motor turns 7.33 times.
Another way to see it: @7,330 rpm the axle sprocket make approximately 1,000 rotations ( 7.33 to 1)
The higher the final ratio number (G) the more torque and acceleration.
Lower the number (G) = more top speed.
Keep in mind this number (G) is to the axle sprocket. Tire diameter plays a part in this too. Taller tires lower the number. There’s another formula to work out the ratio between tire diameter and sprocket rotation
To figure the true final ratio you will want to use IPR (Inches Per Revolution) which means the number of inches the buggy will travel per each revolution of the motor
To Figure IPR:
Rear tire Circumference (X) 22in. is a popular tire size.
Multiply by ( C) 13, outer trans gear. If with reverse this number would be 16
Then divide by ( D) 31, axle gear. (X*C) / D = IPR
( 22 x 13 ) / 31 = 9.22 . This means the buggy would travel 9.22 inches for each revolution of the motor.
The higher the IPR number the faster you go !
With reverse: (22 x 16) / 31 = 11.31 Which shows with a reverse unit your covering more ground. with the same motor rpm.

My error in stating to add the 2 instead if multiplying.

Unfortunately I cannot find the "head exploding" smiley face after all of that reading...

Thanks for the info guys. Unfortunately it's too much for me to comprehend.


What a bummer......

It's a nice day (45* with sunshine) the GF is out of town and I have nothing to do.

Let's go tinker on the kart, right?

Dug out my A11 cam for testing purposes and discover that the exh lobe is excessively worn. Probably got wiped out when the valve kissed the piston.

Figured what the Hell, I'll take the A10 with me instead. Even though I REALLY want the A11 back in there.

Get to the shop and warm up the kart. Take my GPS and finally measure out my 300' track. ( I always called it 300' but was just a guess) It actually measured out to be 263'. Not a half bad guess, and that means my actual speeds should be slightly higher in a REAL 300' test.

As I measure out the track I see 1 lonely ole car in the parking lot. Wouldn't you know it, they are parked in the worst spot possible. Right at the end of my run, and slightly towards the center. So as you come around the corner you're swinging wide and BAM, there's this SUV.

Figured I need to get a 300' run done with the KNM pulley on there for my comparison VS stock. (last time I tried it the large. flat nut was off of the clutch and I got a real hero speed) So I had to try it again.

Kart takes off really good (something is actually slipping in the back end under hard accel. Not sure if it's the drive chain slipping, clutch slipping, or clutch bell slipping)

She winds up pretty good, and then you can just feel the CVT kick in and shift. I never really felt the transition with the stock pulley before. This is a night and day difference. Prob shifted too soon for my liking. Might be because the 14g sliders? Or the stock contra spring? I may have to try the yellow spring like everyone else is running.

Get down to the end and I back off a bit earlier than normal because I see this car. Sure as Hell, I'm drawn right towards it. Thank god I didn't have brake failure because that could have been really bad. Ended up with a 32+ MPH that would have been slightly higher had I not backed off early.

So knowing any test runs were pointless with this car here, I didn't even bother installing the other cam. Pretty much a waste of time and gas. Man was I bummed......

hang In there xlint im sure u will get ur numbers soon good luck

It just isn't meant to be.....

Get to the shop and it just starts to drizzle. One of those where it tinkles for about a minute or 2. Then it stops.

Figured cool, I'll let it dry up a bit and make my run. (was a beautiful day here)

Get the kart warmed up and head over to the testing track. Give her a hard launch and get a little of that slipping/wheel hop I mentioned in a prior post, and a little tire spin. (turf tires on seal coat concrete) Kart pulled as good as normal, but I backed off a bit soon. That tire spin concerned me. Glad I did too. Got down to the end, started my left hand turn and started braking when the ass end passed me up.

She went into a spin and came to an abrupt stop (180*) right in the same spot where that car was parked yesterday. So, no testing done today either.

dam xlint hope u wear a helmet and seatbelt u never know!

If you only knew all the "incidents" I've had with this buggy....

It's more like a bumper car at the amusement park than an off road vehicle at this point.

Gotta hand it to her though, she takes a beating once reinforced.

amen to that! I rolled my yerf the other day on its side and not a single thing broke

Was it from braking too hard????

Lmfao!!!! Still no brakes I just used a mighty vac the other day I also cut the reservoir line by about 5 inches to give it a straight run the stock length is to long and I noticed it kinks. With both of those I was able to pull the brake fluid threw so just have to do 1 more cycle of the mighty vac and pump bleed it and I should finally have brakes and all new.

I can see you doing the FRED FLINTSTONE brake method. How worn out are your sneakers at this point?


PS: who should be wearing the helmet and seat belt??? Jman is a little "tipsy"

Lmao that's some good stuff, yes I do wear my seat belt and helmet lol and gloves.

No glove, no love.

WAIT, wrong forum.... ;)

how u doing xlint haven't heard anything

Weather killing me. I can't do speed runs with too cool temps (tires lose traction) or it's wet out. (no traction)

I can't do any real world tests without a speed run. Otherwise it's just a guess. (worthless)


Losing control in these things over 30 MPH is pretty scary poop.... Especially when your back stop is a 6" curb and parked cars/trucks.

Trust me, it's killing me. I have the A11 sitting in my tool bag just waiting for install......

And I can't install it, until I know for sure what it's doing with the A 12. (Was the "hero run" 33.2 MPH a true speed?)

I also have the 18g sliders here and I want to maybe try a 1500 RPM contra spring. (I feel it's shifting out too soon with e KNM pulley on there) Might try the performance clutch bell (Ban Jing) I have too. Still not sure what's causing the slip/stutter in the rear on hard accel.

sounds like a lot of testing xlint cant wait to here the results.

Got to say I am quite impressed with this kart.

Was out last night with a friend. He was in the Yerf and Ii was in the Honda oddy 350.

Dead stop drag race to the 300' line (actually 265') was almost dead even. It came down to whoever got the jump took the flag.

Don't get me wrong, the oddy was pulling WAAYYY harder in the mid range and started to really wake up when I had to start braking, but it really surprised me that I didn't crush the Yerf. Got to give Kudos to the Yerf with it's 180cc engine holding it's own against a 350cc in a drag race.

Didn't change the Yerf set up, still using the A12 cam and stock CVT with 14g sliders. Still think the driven pulley is opening a tad too soon, I wan to try a stiffer spring and see what happens if I hold the RPM a bit higher before up-shifting.

maybe a a-10 cam and some 16/17 sliders will help with top end, can u take a video of them racing would be cool to see ?

That surprises me. My fl350 would spin the tires on anything other than asphalt.

Jman, that would have been a good idea as today's weather was xlint. (54* and dry) Too bad there was no one else around though. Family stuff going on because of Christmas.

Liduno, the oddy is a little boggy off the line, but rips in the midrange. Not that surprised though, the Yerf is pretty potent in it's latest configuration. I'm pretty impressed with it. 32, possibly 33 MPH in under 300' from a dead stop isn't bad at all. Esp when it tops out at 40 MPH.

Yup that sounds like a bad ass little yerf

I bet the yerf weighs 200 pounds less then oddy that's alot espically on buggy

That's true, power to weight ratio is something a lot of people forget about.

100 pounds off a 4000 pound car doesn't make too much of a difference, but 100 pounds off of a 400 buggy makes a huge difference.

Yerf 407 lbs. And I'd have to guess I added almost 40 lbs to it with steel reinforcements, reverse gearbox, axle reinforcements, etc.... Rated at 7.8 HP stock, with mods I'm guessing I might be close to 10???

http://www.yerf-dog.com/products/3206.html

Stock oddy dry weight 602 lbs Rated at 28 HP

https://docs.google.com/file/d/0B851...4Zw/edit?pli=1

Sorry for the lack of updates, but it's been running really well as is.

Took her out to my uncle's on Mem. Day week end and put a real beating on her. Family (mostly kids) loved the the semi bald rear tires in the grass. They were drifting and doing donuts all day long.

Had a no start (no crank) conditionand found the main ground wire between the engine and rectifier had broke. New connector end, and all was good to go again.

Lost a rear fender support, so tied it up with wire. Then lost the 3 screws that holds the bottom to the frame. Saw the fender flapping in the wind behind the buggy.

Don't you love it when you ask people "didn't you hear anything odd?" And the reply was yeah, but we kept going. :ack:

It seems to be vibrating a bit now since then, so i need to do some investigating.

LOL. I know the feeling. Been since high school since I welded anything. And learned all over again on the YD. I know for a fact that I have still a few shady welds on it. most of them have been fix because they did break. But never fails, it's after my son comes in, and I hear a clanking, or shaking noise. I ask him the same question. But his answer is, Ya, but it wasn't getting any louder. Or my favorite... Ya, but the noise stop when I stopped. :cussing:

But I know what I've welded and find the issue pretty fast.
So far everything I have fix, has been solid. So tells me I'm getting better. :biglaugh:

Kids are getting more ballsy with it thou. Think I need to mow and clear out a small circle track for them on some lvl ground. Seems like every time we go out, the engine revs higher every time.

Was trying to keep up with my boss in the Oddy (did pretty good too)

Ended up dumping her on its side again..... OUCH!!!!

How can you get road rash on your elbow and not even tear the sweatshirt you were wearing?

Guess I need more HP . That way the tires won't hook up and tip me over. Instead they'll just break free and I'll do a bad-ass burn out!!!! :)

what was you racing with the oddy?

This Yerf. :)

Lol so what r u thinking of for more hp?

How about a 350 2 stroke Honda? :)

Just go for it all with a small V8.:drive::laugh:

I have an extra 4.7L Supercharged V8 in my shed. Although it weighs more than the go cart LOL.

There you go Xlint89, that oddy won't know what hit him.:laugh2::party::drive:

Actually, I wouldn't know what to do to the existing engine. It's pretty "tweaked" already.

I'm afraid I would need to do an engine swap to see any major gains.

Only things left to do on this one would be a slightly larger piston (83mm) and a longer stroke crank (2.2mm already installed) Possibly a 4 valve head?

Not much gain for the $$$ invested.

u mean 63mm piston lol, maybe try the 4 valve head with one of the taida camshaft selections ?

forgot another idea. Add a oil cooler

Oops, typo, Yes, 63mm


As mentioned earlier, I think an engine swap is in order before dropping the $$$ on a good quality 4 valve head.

Could prob get a bike, sled, or ATV engine for the cost of a 4 valve set up and see some real HP gains.

guess your going to have to start a new thread lol. I was thinking the same thing xlint. By the time I spend the $$ on a fully built taida engine I can find something with a bigger engine for 1/4 the price depending on condition. But also comes the part of finding the right option for a swap and the part of getting a hold of people and going to drive to get the vehicle.

Yep, right donor vehicle is key.

If done right, reverse can still be maintained

external reverse
 

hello i have a 150cc bored out out to a 180cc anyways its a twister hammerhead buggie with a external reverse and i need the nut tht goes here does anyone knoe wat size it is so my reverse will work?

It is a 16mm X 1.5 pitch. If you have a Fastnal near you they should have it or they can order for you. If you are in a bind I have them but I need to know if it is a castle nut or lock nut. If the shaft has a cotter pin hole in it you need the castle nut. I can be reached at 662-301-1563

There you go, Tom will take care of you

Toms like the "Shell answer man" on here!

Well, think we might have "bitten" 2 more guys....

A couple buddies of mine finally came out to play tonight. They were all jazzed up about the Oddyssey. They loved it.

When buddy #1 was asked if he wants to switch back into the Oddy, he says, "nah, this one is fun" :)

It started raining a little bit, and with the bald ass turf tires on it, he was breaking free the rear and having a blast.

Ironically, he did the EXACT same thing I did a while back. Buddy #2 was parking the Oddy and with me pointing where to park, I hear a THUD/SCREECH....

He attempted a donut in the opposite direction and dumped her on her side. Same spot, same scenario, everything identical. He was fine, just some small road rash on his elbow is all. And the kart is fine too. Just some fresh scratches on the same dented roll cage tube.

Long story short, they loved it. Then the question flies around..... "how much is one of these"

:banana::banana::banana:

I need to do the same. Take the old yerf tires, smoke them out a little, and make some good kitty tires. Rather just have a spare set of hubs, so be easier to change out.

Yes. much easier. I have front and rear mud tires also, it's just normal for us to ride on asphalt. And that tears up knobbies fast.

Went to Mines and Meadows in Wampum PA this week end. To my surprise the Yerf did better than expected. This kart never ceases to amaze me.

The trails were too much (giant ruts that would have bottomed out the Yerf and the Honda Oddy) for the Yerf and the kids that were with us, so we didn't get to REALLY check the place out, but we stayed in the open field where we could have some fun and it performed flawlessly. Only issue is that damn suspension.

My nephew says I know what to get you for Christmas. SHOCKS

That and some better seats, those stock plastic ones really do stink.

What are you guys running for aftermarket seats and how hard was it to install them? Thanks

Mothers Day weekend - they got to ride for free. My sister in law was the redhead wearing a neon yellow shirt on the news. I couldn't make it because of work, but I live across the river from Mines & Meadows in Ellwood City.

I got Jegs 70250 highback. 2. It's a better seat. The seat belt holes on top help keep seat belt off your neck. Greatly helps for smaller person. Bought a padded seat cover for it. With the 2, pretty good improvement. I still need to add padding to it. We still use old pillows or cushionsomething, for better ride. The lower back of seat dips in, so pillow helps greatly until can add padding.
Be careful, on the width of seat. Not much room. This seat I bought, is absolutely widest it can be. If put 2 seats in, the seats would be touching each other. And up against the frame.
Installing, I tried to make a bracket, to match the bolt pattern. (Could not find seat with matching bolt pattern)
The bracket wasn't work like I thought. So best way, was to cut the seat mount, and move it. Only had to do one. Had to drill a few new holes. Was a pain. But in long run worth it. And still able to use the stock slide adjustment for the seat. Hint, more likely no matter what you get, you going to need to adjust the mounting bracket. One or both. A 4 1/2 cutting wheel able to get most of it. But a Dremel cutting wheel came in very handy.
Your limited on what kind of seat due to the width. Unless you going to adjust the frame outwards. Can't say for sure if there is a different seat that has same bolt pattern, they come close, but in the end was better to cut the mounting bracket, and move it.

Sorry I haven't posted in a long time guys. Been very busy with other stuff.

Took the buggy out to the uncle's on labor day week end again and the buggy did fantastic.

The semi bald rear tires in the tall grass is a hoot!!!

We were running around the field like a race track just flat hauling butt. Coming back towards the front we would cut across the middle into the virgin grass and just yank the steering wheel one way and she would immediately go into a 180*.

Scared the kids and the adults the first time I did this with them on board, but they would then ask, "let's do that again." :)

It was a really fun time and the buggy with all it's mods holds up extremely well.


Now for the bad news....... :(

Unfortunately, I am losing my riding/storage place and don't ride the buggy nearly as much as I once did. The nephews don't have a place to ride it either.

So, I am offering this up for sale if anyone is interested in coming up to the Cleveland area.

She's not the prettiest girl at the dance, but it is a beast and is a lot of fun to drive.

It will come with everything I've accumulated for it over the years as well. Things like stock parts, performance parts, extra tires and wheels, new conversion axle, and extra engine cradle.

hate to hear you have to sell it