View Full Version : HammerHead Twister 2 Seater

12-13-2015, 06:45 AM
Picked this up for the kids (ages 4 and 5). Its Tiny, only 34" wide.

Original engine was a no name 50 or 80 cc, it has been repowered by a Honda GC 5hp by the pervious owner, which is more than enough for this little thing. For sure will be dialing back the gas pedal stop, it did 18mph with my 175 lbs in it!

It has a centrifugal clutch to a jackshaft, so some options to regear if needed. At first I was worred I was going to want a CVT but I think it has plenty of power to get moving with that big of an engine. Doesnt slip the clutch any with me in there. Will see if it has any problems on hills with the kids.

Plan is to add a remote kill setup so it can be shut down by us if needed. Will put the stock gas tank back on with spacers (to clear the valve cover on the Honda) to provide a shield to prevent them from touching the engine when in the seat.

Eventually would be cool to put an engine with a charging system on to run lights.

Maybe even widen it out as they get older and drive faster.

Will need to find 2 kids helmets, hoping some pop up on craigslist.

They have not seen it yet, going to wait till christmas.

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/00p0p_dv0D2flauz9_600x450_zpsaih3bwyj.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/00p0p_dv0D2flauz9_600x450_zpsaih3bwyj.jpg.html)

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/00H0H_90dcwc2VSBL_600x450_zpsb7pxrfi5.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/00H0H_90dcwc2VSBL_600x450_zpsb7pxrfi5.jpg.html)

Hammerhead still makes a buggy this size and not much has changed other than having a 136cc engine and CVT.

HH Torpedo™ | Hammerhead Off-Road (http://www.hammerheadoffroad.com/product/hh-torpedo/)

12-13-2015, 05:23 PM

12-13-2015, 06:33 PM
Those came with a whopping 47cc weedeater engine that couldn't even pull up a slight incline. Look for a cheap used kid's 70-90 cc atv, putting the a-arms from that on the front end like I did makes it soooo much safer. Cool beans, gonna be two happy lil campers! did you smack the back of your noggin on the cage a few times? I still haven't finished sanding my daughter's down for its repaint. Had hoped to have it out for sale pre-christmas.

12-13-2015, 07:55 PM
Safer because wider?

Naw I'm 6'3" tall. I was sticking out the side.

Scored these off craigslist tonight. Hope they are small enough.

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/IMG_21301_zps2wlefawi.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/IMG_21301_zps2wlefawi.jpg.html)

Found this video online. Kids got skill

12-14-2015, 07:18 AM
Ha ha .... my wife would freak out if my son came around the corner like that. Of course, I would give him a high five.

12-15-2015, 08:07 AM
Last night moved the pedals back to shortest position and made some spacers that will allow the stock fuel tank to mount above the engine. Want it there as a heat shield. Going to add the throttle stop, and maybe shim the engine to tighten up the chain then it should be ready to give.

Also want to add the remote kill. I think I have one picked out.

12-15-2015, 09:28 AM
Cool stuff Mike!

Engine looks like a big block sitting on there!

Post some dimensions, I'll draw a new upper cage with BT. LOL!

EDIT: that passenger is in for a surprise sooner or later.

12-15-2015, 12:58 PM
Great stuff! Your munchkins are going to be thrilled.

The kids in the video will be rally racing in 10 years. [smilie=thumbs_up.g:

12-16-2015, 08:53 PM
Added gas pedal stop and finished gas tank mounts. Pulled the carb off and apart and ran through ultrasonic cleaner. Was dying at idle but ran fine at higher speed so hoping idle passage was blocked.

Going to redo the throttle return spring correctly while I have it appart.

Will get a feel for if it will run slow enough with the throttle stop or if will need to regear once I get the engine back together.

Had to rake shut the trenches I cut in the gravel hooning around last night...

12-17-2015, 04:57 AM
"Had to rake shut the trenches I cut in the gravel hooning around last night... "


12-17-2015, 05:37 PM
Well shucks. With the current gearing I can't slow it down enough. Has a 12 tooth sprocket on the centrifugal clutch. I see they make 11 tooth for 3/4" crankshafts. Will do some math to see what that does for mph.

Good news is the engine idles now that I cleaned the carb. And the remote kill is supposed to be in tomorrow.

And the definition of a hoon, sounds about right ;). http://metro.co.uk/2010/03/26/what-is-hooning-or-what-is-hoon-driving-194614/

12-20-2015, 01:41 PM
With the engine throttle stopped at 2600 it does 9-10mph. won't go any slower as clutch engages around 2500rpm. I'm collecting parts to make the clutch engage lower and hopefully I can keep the top speed down them. 5mph to start out would be sweet.

Also not sure how it will do on hills.

12-21-2015, 08:06 PM
Clutch is only a few hundred rpm lower and rough engagement.

Might end up with a CVT yet....

Remote kill showed up and works.

12-24-2015, 05:51 AM
It's good to hear the remote kill works. Great piece of mind. The kids are going to love it!

12-27-2015, 12:44 PM
sweet Christmas for the kids!!!! I never got toys like that probably cause they saw what I did with my bigwheel. freestyle was alive long before these kids on dirt bikes lol!!!!! Wondering about the motor could you swap fly wheel from lawn tractor or new if it fits they have the magnets etc for lights epoxied to the rear of them and a separate pickup my snow blower has one lost the magnets but powered lights on it doesn't effect the running at all may not be as hard as we think to set up that motor to run lights. maybe they have the same motor with them and just get parts and swap them over?????? just a thought

12-31-2015, 07:37 PM
We got 6" of snow so holding off on revealing it to the kids. Still need to wire in the remote kill and waiting on a buddy to dig up a CVT.

Good thing is been putting the helmets to good use giving the kids rides on the snowmobile.

01-15-2016, 09:56 PM
Purchased a Comet TAV2 CLONE torque covertor for around $80 shipped today. Should see it later next week. Should allow me to slow the thing down nice and not have any worries about clutch slip.

They do offer a few different springs for the primary and secondary's on those TAV2's so can further dial it in once installed.

01-16-2016, 01:03 PM
good choice switching to CVT
we use mechanical clutches on the kids race buggies because you can get higher top speeds on the track.
but cvt is much better for universal driving and better low end

watching kids have fun is almost as much fun as driving yourself :D

01-16-2016, 05:21 PM
Nice and yes I have more fun watching kids enjoy than myself!!! they seem so excited more so than us! well maybe they just show it more than us I built custom one off Honda civic full molded body kit spoilers bbs wheels etc for nephew when he first got his license he was so stoked it was worth every late night I put in car. even my father was like holy fing shit it looks like its going hundred mph sitting still. That's whats its all about!!!!!!!!!! your kids will love that thing hell I want one just to have it and I don't have kids

01-18-2016, 05:54 PM
Thanks guys. Things are escalating quickly.

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/IMG_20160118_181845_189_zpseggu7byb.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/IMG_20160118_181845_189_zpseggu7byb.jpg.html)

Also got a line on an engine with electric start and charging system.

01-20-2016, 08:25 PM
Wonder if these lights are any good? Will only have 10 amps of charging for battery charging, lights and the remote kill so led lights are probably a wise idea I would think.

12V LED Head Light Front Headlight ATV Quad 4 Wheeler Go Kart Roketa Sunl Taotao | eBay (http://m.ebay.com/itm/12V-LED-Head-Light-Front-Headlight-ATV-Quad-4-Wheeler-Go-Kart-Roketa-SunL-Taotao-/191641752053?nav=SEARCH)

02-10-2016, 11:05 AM
Working on the mount for the new engine/cvt combo. Going to make it pivot to allow for chain tensioning. Of course, adds complexity, but should work well when done.

02-10-2016, 07:02 PM
I bought some really cheap LED lights like that once, ONCE. I would pass on those if I were you and try to find a small LED light that at minimum tells you about the lumen output and power draw. Check out amazon at least on there you can read reviews and some people put pics if the products in action.

02-12-2016, 09:59 AM
I've worked with this place on several projects for work, they have tech that know their stuff, anser the phones and ship fast with good pricing.


02-14-2016, 05:00 PM
Progress! Swing mount for engine to tension chain. It and the frame will get tabs at rear for bolt with jam nuts.

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/IMG_20160213_181125_823_zpsnxvnltys.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/IMG_20160213_181125_823_zpsnxvnltys.jpg.html)

02-14-2016, 05:03 PM
And the engine. changing the angle of the shocks to allow it to mount that far forward. Rear was real stiff so should actually help soften it up.

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/IMG_20160213_181350_374_zpsbf6l83ko.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/IMG_20160213_181350_374_zpsbf6l83ko.jpg.html)

03-08-2016, 05:17 PM
Everything tacked together for the swing mount. Can see the bolt for adjusting chain tension. Hope it works well.

http://i22.photobucket.com/albums/b309/duwem/IMG_20160306_163609_235_zpscjlej4x1.jpg (http://s22.photobucket.com/user/duwem/media/IMG_20160306_163609_235_zpscjlej4x1.jpg.html)

http://i22.photobucket.com/albums/b309/duwem/IMG_20160306_163649_398_zps0ftl2kr2.jpg (http://s22.photobucket.com/user/duwem/media/IMG_20160306_163649_398_zps0ftl2kr2.jpg.html)

03-13-2016, 10:58 PM
Well, went for the first test drive since the powerplant/cvt swap. Runs nice and slow now with no clutch slip with my 175lbs in there. The $80 Comet TAV2 knockoff wobbles a little on the crankshaft when running, must not be made quite true. Should work fine for this thought.

Will use the gas pedal stop for a while, when the CVT upshifts she really scoots!

I'm going to build a whole new harness for the remote kill, electric start, lights etc for the kart so that will take some time.

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/IMG_20160313_163425_zpssl6wegsp.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/IMG_20160313_163425_zpssl6wegsp.jpg.html)

http://i22.photobucket.com/albums/b309/duwem/Mobile%20Uploads/IMG_20160313_163240_zps6kkjchje.jpg (http://s22.photobucket.com/user/duwem/media/Mobile%20Uploads/IMG_20160313_163240_zps6kkjchje.jpg.html)