Used to race heavily in Fl. back in the mid 70's thru mid 80's. Had a blast and learned a lot of good driving skills. Ran Mac's and Yamaha when they first came out. Still have my Mac's on the kart in the shop. Glad to see they is still interest in these awesome little machines!

Nothing sounds sweeter than a pair of well tune B-Bombs running 2-carbs per engines and C-open would be running alky carbs(I ran A-Stock Jr.back in the day!!lol Sprint and Enduro)( K-77 Komet and the K-88 Komet)

Sorry for the following love rant. LOL I tried my friend's Stinger with a Mac 91B once. I was honestly shocked at how every nerve in my body resisted the speed! It wasn't for me. OTOH, Back in about 1968 I built a Flexo Big bear Scrambler minibike. (very small) It had a Mac-75 with stuffer manifold, 12:1 high compression head gasket, DUAL carbs, with straight pipe. I had a 10:1 gear ratio, (Chain) It had a centrifugal clutch that engaged at 4,000 RPM. It sounded raggedy until you hit maybe 8,000 RPM(?) Then it leaned out and SCREAMED. I always regretted not using progressive linkage which would have opened one carb at first, then the other one as you increased the twist-grip. (More low-end torque.) I told my friend, "Now ease on the throttle real slow, or it will throw you on his ass!" I did a demo and everything. He got on it went ten feet and it threw him on his ASS! LOL!! GREAT video.

@KrustyKlown

3 жыл бұрын

A Twin engine MC101 kart feels twice as fast as a single MC91B powered kart... and a twin engine B-Bomb kart feels twice as fast as a Twin MC101 kart, and feels faster accelerating than any modern class Sprint racing kart in a straight line.

My great grandfather raced these in Kansas City, Missouri, used to set records back in the day... Now the track doesn't exist and I can't find any records of it

That is a fast kart. I drove my friends Hartman with twin Macs it was fast. I ran several seasons in OKC in the late 80s with an Invader and a Mac 92. Great memories.

Good video, really captures the experience. Driving a racing sprint kart is a violent experience - you climb out after a good ass kicking!

Thanks A lot Man!!! You just made me want to get into building these awesome beautiful machines! Lol Awesome videos dude

I have a couple karts ,but nothing like this beauty would love to just drive this kart

Attended the IKF "Sprint Nationals", Once, at Camden .... Drawn There PRIMARILY by a Desire to see the C-Opens on the "Monza Wall", there, at that Time : ) ..... Was NOT Disappointed : )

Liked the basic edit sequence. Introduction view of the kart (just right). The one kart practice lap (felt one lap would have been sufficient). And, final scene with the race was good. If able and available--and know difficult to shoot--would like scene cuts within driver's view to include spectator view. Thank you for sharing.

that's so SWEET. love the sound of a dual. crazy story, actually I and a few people actually made the first simese twin. :) it was made by Steve Greenland and Bob Kindal here in van Nuys and driven by Greenland at Indian dunes california. look it up that thing was incredible. was Pullen over 65hp on dyno and sounded I credible.

That's a real go kart. Unruly and loud. I miss those days back in the 70s and 80s.

I used to late spring race back in the mid to late 70's thru the early 80's. the Yamaha KT100 was out and popular. 4 strokes were just coming on. The open class was very popular with Komets, BM, Corsairs. What killed the open 2 stroke classes?

Nothing like seeing karts from my childhood whish I still had one the ring of the Exhaust is music to me

Such beautiful music that is...........

B Bombs 😎

The chassis is a reproduction of an early 1970's Invader kart, Sprint Twin model.

What a rush!

thanks :)

Sounds great and looks like a ton of fun. I would like to see this class come back on a new chassis.

@VintagePowerSport

9 жыл бұрын

quintanaroo roo I always thought a dual 125cc TAG motors would be a hoot on a modern style chassis.

@Quintanaroo2117

9 жыл бұрын

VintagePowerSport sadly those new tag motors don't sound very good. I'd prefer the older style of engines.

@gyula6516

7 жыл бұрын

VintagePowerSport just a question how can 125 +125 be 270...

@marcwagner9369

7 жыл бұрын

Gyula RS6 135ccm per engine ( formula k )

@VintagePowerSport

6 жыл бұрын

Right, motors are 135cc, in the 1980s the increased the displacement to 150cc (300cc dual) to allow people to get more life out of the cast iron cylinders .. The 135cc size goes way back to the historic origin of karting in the USA, where existing 2 cycle industrial engines were prevalent in several sizes, one being around 8.2 cubic inches or 135cc .. and the other size being 5.8 to 6.1 or around 100cc. So, when the Italian kart engines first showed up, they were mostly 100 and 135cc .. and those 2 sizes of motors comprised most karting classes Word wide for decades. Then when shifter kart engines became popular, the standard size of 125cc took hold, and became the size basis for 125cc TAG motor.

I hate them plastic brake lines they get hard and break up like fortune cookies.

Just wondering , how much does it cost to build a cart like the one in the video ? My guess is several thousand dollars to build one like the one in the video ! , thanks , jd

@VintagePowerSport

6 жыл бұрын

The motors are rare, especially the left hand ones .. a pair of tuned, rebuilt motors goes about $5,000. The engines, reproduction frame, exhaust pipes/headers, gages, clutches, sprocket hubs, wheels, tires, ..etc.... all totals out around $10,000. ... and normally it would be wise to take a pair of spare motors and parts to the track, cause this stuff breaks a lot. It gets expensive . but, there are many vintage kart classes, and most people run in the single engine McCulloch classes that do not cost a fortune, and are a heck of a lot of fun ... one could buy a used setup for as little as $1000.

What kind of exhaust pipes you run

Does anybody remember Mickey McCarthy? From New York Rochester. I think it was 77 he was IKF Grand national Champion C Open. He was my good friend. Well Mickey passed away.

The karts in front of this driver are twin engine also.

So the single engined Karts were all ahead of this dual engine Kart? Interesting......

@VintagePowerSport

9 жыл бұрын

spugsautorepair its a vintage dual engine class, the karts in the heat race are all duals ...either IAME rotary valve 135cc B-Bombs or BM-130 135cc rotary valve motors.

@seanjarvie9737

7 жыл бұрын

What sprocket sizing were you running I've just finished putting twin iame k25's on my kart but haven't got the sizing right yet any information would be good

wierd looking twin carbs? how r they fed to inlet?

@VintagePowerSport

6 жыл бұрын

Those are rotary valve intake motors .. no reed valves or piston port intake. Both cards feed into one passage through a cut out in a steel rotating disk on the crankshaft. Rotary Valve 2 Strokes have a reputation for being the most power type of 2 Stroke engine, but also the most complex, and challenging to use. The location of the carbs and rotary valve are not convenient for power take off or mounting of the ignition system. On this kart, we run the clutch off the ignition side of the motor, using a screw on adaptor shaft and outboard 3rd bearing .. its a mess, but that is how it was done in the day ... its very difficult to get it all running true & vibration free .. and the adaptor shaft has a habit of spinning off trashing lots of expense rara parts !!!

i have i chassis just like that do you know what model or any info on it?

@VintagePowerSport

6 жыл бұрын

it is a reproduction of a 1974 dual Invader Kart ..fyi - ad page for original.. bigcooter.com/wp-content/uploads/2012/07/1974-Invader-Twin-ad-002.jpg

I just made a game looking like that video

i drive a tkm junior

It sounds like your engines are revving slightly out of sync

@VintagePowerSport

6 жыл бұрын

That is the beauty of the historic dual engine sound .. the engines are not synchronized, each engine spins independently with an oil slipper clutch, both both drive the same solid rear axle. Every time the clutches lock up around 11,000rpm, the sync is different.

so this is dual kt100 ?

@mikepsychles

6 жыл бұрын

This kart dual 135cc (8") Komet rotary valve OPEN - meaning that's 270cc with no rules on porting or bore, etc. That's where that fantastic sound comes from. And, if this drive is who I think he is, he outweighs most of these guys as he's a monster of a big guy... but he's done a hell of a job with this kart (and getting better at driving it all the time).

top speed ???

@JimRoberts-mg2kc

5 жыл бұрын

on a lay-downer...about 140-145 mph on a long track like garnett or green valley. I raced karts from 1959 to 1971. good times

dar wakelt ales

Why not use air filters to protect those EXPEN$IVE engines?

@VintagePowerSport

6 жыл бұрын

some guys run air filters or screens (rock protectors) .. it's a toss up ... such things are limiting when trying to start engines .. choking or restricting fuel flow or simply viewing if fuel flow into carb throat is correct .... these are sprint karts, you get about 1 minute to fire up your motors and get onto the track, each of 3 heats. Lastly, these older motors do not run many minutes before needing a rebuild or blowing up anyway, some extra dirt or a small rock going into the carb will have little effect on how often engines get rebuilt.

@jbratt

5 жыл бұрын

I always ran filters on my reed and piston port engines. Never on The rotary valve. I did run an air deflector on the road race kart with the rotary valve so the fuel would not siphon out. 😄

Too shaky to watch

kinda overkill for such little power, just being honest.. a 250cc 2 stroke/.honda engine would crush this

@rednecklife-uu3je

9 жыл бұрын

Rob M Thats what i was thinking... Shifter karts are the way to go.

@VintagePowerSport

9 жыл бұрын

Rob M you are missing the point, this is a vintage kart, setup to current VKA vintage racing guidelines to represent the dual engine C-Open classes run some 40 years ago. That said, what makes you think a 250cc MX shifter engine puts out more power than TWO full modded rotary valve IAME B-Bombs running methanol, LOL, it ain't close. Back in the day, this class was open to gearbox motors up to 270cc, NOBODY ran one competitively against the dual 135cc Italian rotary valve kart motors. However, for fast fun on a modern chassis, a reliable CR250 gearbox motor would be a great ride.

@airgunningyup

8 жыл бұрын

Yes I prob am

@barrettcraig963

7 жыл бұрын

yeh, but you gotta admit getting that kind of response from single speed engines is truly phenomenal.....

@kbol4054

6 жыл бұрын

You wouldn't have the proper balance Rob. That 270cc would eaten you alive! I've driven one of them. That puppy just lights into the ground! It has so much torque the Kart chassis flexes the front wheels get so Light you better have That thing aimed before you mesh that pedal down because there ain't no steering it when it hook's up! Those engines Will wind out about 16,000 RPMs!

Too much Power - and you need to be a LOT smoother - not so "on" OFF throttle - Up in Gear and much smoother - make the motors work for you - I would have lapped you.

@markkeeton9357

5 жыл бұрын

Hollywood man you are so clueless