Slide Carburetor

Slide Carburetor

Ideal Jawa Yezdi Roadking

Origins

The Yezdi Roadking was originally based on 1974 CZ,where the original bore x stroke of 70 mm x 64 mm was retained as it was, but with less power than its Motocross original. The engine block is smaller and different from the Yezdi Classic in appearance. Also the CZ original had the famous Porcupine Head while the same was used only in initial models, later reverted to regular straight fin design. The cylinder block (Type 980.5) was from CZ.

Chassis frame

The chassis frame is single frame of motocross origins and was built out of square tube. The fork was more pronounced with a higher rake angle and came with adjustable shock absorbers. Rims were 16 inches. The motocross and ice racing origin frame and proper weight balance made handling very easy and agile compared to its rivals in India.

Engine

The cylinder block was from CZ which had an over square bore x stroke. Carburetors were either Jikov (tickler choke) or Pacco (press type choke) of which the earlier was exclusively for Roadking, while the latter was used for Classic models. The spark plugs were of cold type and the bike also featured a semi-automatic or auto clutch, where a cam inside the gearbox housing automatically activated the clutch through a cam which is unique to this and other Yezdi models in India. The familiar Jawa-CZ twin exhaust ports made the unmistakable sound when the exhaust flute mufflers and end-cores were removed. Another unique feature of the bike was that the kick-starter and the gear shared the same rod as with all Yezdi models. Once the gear rod is reversed it doubles as a kicker and once started it automatically returns to the original position.

Models and types

CB unit models

The bike was silently launched in India in late '70s by Ideal Jawa and was a rare sight even in those days. The bike had a prominent petrol/fuel tank and the colour was Jawa Maroon and sometimes in black and gold pinstripe, priced slightly higher than the best selling Classic and CL II models. The troublesome contact breaker ignition was later replaced in 1993. Till 1989 the RoadKings had a provision for adjusting the front fork dampers.

Oil King

During late 70s another model known as Oil King was also launched which featured a oil pump for the 2T mix with petrol but later production ceased. The prominent protrusion of the left hand side gearbox housing was the original location for the pump. Though the model was discontinued the engine casing found its way into the Road King and hence all Road Kings have this protrusion even though the oil pump was not housed there anymore.

Cdi unit models

In 1993, in an effort to increase fuel efficiency and to solve starting problems the CB or contact breaker ignition units were replaced with Cdi electronic ignition units. The electrics were changed to 12 volts from 6 volts. The livery was also changed with some new graphics. The fuel efficiency was increased by 30%, but still its competitors were getting better and with rising fuel prices the sales plummeted down until finally it ceased operations in 1999.

Monarch

In 1996 Auto Expo Yezdi displayed a model which used the Yezdi 350's twin frame, Roadking engine and a sleeker fueltank. The rims were 19 inches as opposed to the regular 16 inch. However, it sold only few numbers. Although some attribute its low sales volume to the company's need to get rid of the additional Yezdi 350 frames that remained in the factory after the twin model was stopped. However this is disputed. One of the finest engines ever made in the history of indian motorcycling.

Sale on Premium

This was the only bike in India to sell on premium for foreign currency, you would get a bike only if you paid $300 in American dollars and not even if you paid the equvilant in Indian rupees.

In Indian motorsports

In road races at Sholavaram, it ran in its own 250 cc class while in the Indian open class category its main rival was Enfield Bullet and later the much more powerful Rajdoot 350. Power was usually increased to 25 plus bhp or beyond for Group E categories where the engine was bored up till 300 cc and the engine was over-engineered in stock trim. In track racing the most famous was C.K.Chinnappa and Somendar Singh.

In rallies the rallyist couple Jagat and Anita Nanjappa and Thirumal Roy won several victories before switching to Rajdoot Yamaha RD350. Later, in 1991 both the bikes were banned from rallying, but the ban was briefly lifted in 1996, when Rajdoot 350 went out of production. During those later seasons TVS Suzuki had its own factory team with Supra and Shogun, while Team MRF had several Escorts Yamaha RX 100's in the fray. But still one or two privateers took it to as high as second position during the events and setting some fastest stage times.

World Record: First, Fastest over six continents

Deepak Kamath (25) and G.H.Basavaraj (34) of Bangalore covered 42,038 km over six continents on their Yezdi Roadking motorcycle in an expedition called "The Yezdi Castrol Continental Ride". Their expedition began on 8 October 1994 and ended on 3rd Feb 1995. Though the total number of days was 119 days, the actual riding time was 47 days. Thus they became the first to circumnavigate the globe in the shortest period of time.

In Powergliders

The Roadking engines were a favorite among the Powerglider manufacturers in India. One Coimbatore based manufacturer headed by late motor racing legend S.Karivardhan manufactured and exported several Powergliders using Roadking engines with aluminium heads, K & N filters and sleeved bore.

Further developments

As a result of power glider efforts, Somendar Singh in 1996 developed a refined engine with aluminium engine with increased power and fuel efficiency and was featured in Car & Bike magazine. But the design was never put into production even though it ended up with Ideal Jawa.

External links

Official Ideal Jawa site

Czechoslovakian cousins

Annual Jawa/CZ/Yezdi Day Gallery

Categories: Ideal Jawa motorcyclesHidden categories: Articles with peacock terms from July 2009 | All articles with peacock terms | Articles lacking sources from July 2009 | All articles lacking sources
About the Author

I am an expert from China Hardware Suppliers, usually analyzes all kind of industries situation, such as resaw wood , sliding table panel saw.

1991 suzuki lt-f250 quadrunner carburetor?

the carburetor is messed up so i went to have it rebuilt and they told me that i would have to buy a new carburetor because the slide wore a groove and it was letting air in. is there anyway to fix this without buying a new one and if not is there any good websites that would have a new one sorta cheap?

You will likely need a new/different carb if the slide has a groove, check eBay.

OS Engines 30VG(P) ABL 21E Slide Carburetor