Rochester Monojet Carburetor

The 1MV monojet carburetor is a single down draft unit using a triple ventuir in conjunction with the plain tube nozzle. The main venturi is 1 7/32″ in diameter and the throttle bore is 1 7/16″.
Fuel flow through the main metering system is controlled by a main well air bleed and a fixed orifice jet. A venturi velocity power enrichment system is used to provide good performance during moderate to heavy acceleration and at higher engine speeds.
An exhaust gas recirculation, E.G.R. system controls oxides of nitrogen emissions. The E.G.R. valve is operated by a vacuum signal taken from the carburetor throttle body.
A vacuum supply tube installed in the carburetor throttle body connects by a passage to timed vertical ports located in the bore of the throttle body and float bowl. The ports provide a vacuum signal to the E.G.R. valve in the off idle and part throttle operation of the carburetor.
The E.G.R. valve, mounted on the intake manifold, circulates a metered amount of exhaust gases to the combustion mixtures to lower peak combustion temperatures, thereby reducing oxides of nitrogen during these ranges of engine operation.

The E.G.R. system is not in operation during the engine idle.

A pleated internal paper fuel inlet filter is mounted in the float bowl behind the fuel inlet nut to give maximum filtration of incoming fuel.

The carburetor has an aluminum throttle body, a thick throttle body to bowl insulator gasket, and a internally balanced venting through a vent hole in the air horn which leads into the bore beneath the air cleaner. The float bowl is externally vented under extreme conditions through a pressure relief valve system.

The carburetor part number is stamped on vertical section of float bowl, next to fuel inlet.

An idle stop solenoid is used to control idle. The solenoid is electrically  controlled through the ignition switch. When the ignition switch is tunred off, the solenoid is denergized, allowing the carburetor throttle valve to close further, preventing the engine from running after the ignition switch is turned off. On manual transmission models, the  solenoid also deenergizes when the clutch is disengaged.

Rochester Monojet Identification

Monojet Identification

1980 Monojet 1ME Exploded View & Parts List

1981-85 Monojet 1ME Exploded View & Parts List

1985 & Later Monojet 1MEF Exploded View & Parts List

Float Level Adjustment

Monojet Float Level

Fast Idle Cam Adjustment

Monojet Carburetor

Vacuum Break Adjustment

Monojet Carburetor

Choke Coil Lever Adjustment
Quadrajet Adjustment

Trouble Shooting the Monojet M MV Carburetor

Adjust the Idle Mixture

Recent Posts

Late to the Electric Party

April 1st, 2016 Tesla unveiled their much anticipated Model 3. Thousands put down deposits, even though Tesla itself says, “Model 3 will begin production in late 2017,… ” That’s a long wait, but early adopters aren’t easily dissuaded, as shown by demand for the impressive Tesla Model S. But just how innovative is the electric car?

1890: the party begins

Electric Car

The first four-wheeled electric Vehicle took to the roads of North America in 1890. Eight years later Ferdinand Porsche (yes, that Porsche,) was driving his electric P1, which he followed with the worlds first hybrid car. By 1900 28% of the cars built in the US were electrically-powered. (Admittedly, only 4,192 cars were built in total that year.)

1900 saw the founding of the Baker Motor Vehicle Company in Cleveland, OH. One of many electric car start-ups, Baker prospered, thanks to a reputation for quality, until the arrival of the electric starter.

What really killed the electric vehicle

The Model T launched in 1908, and the rest is history, as they say. Well not quite. Many people weren’t convinced of the benefits of internal combustion. The early gasoline vehicles were noisy, smelly, and hard to start. They had a crank at the front of the engine that had to be turned by hand. When the engine “caught” and started to run the crank would fly around, injuring more than a few automotive pioneers.

Thanks in large part to Henry Ford’s efforts, gasoline powered vehicles were less expensive than electrics. By 1916 a Model T could be had for $650, (not an insignificant sum,) but an electric roadster would run around $1,730. Economics played a part in pushing out the electric car, and Baker Electric were one of many to cease manufacturing, but the final blow was delivered by one Mister Charles Kettering.

Now largely forgotten, (except by the students attending the college named after him,) in 1912 Kettering invented the electric starter. Instantly, this changed the acceptability of gasoline vehicles. Sales grew rapidly while electrics disappeared, until the late 1990’s.

They’re back!

Electric cars were largely forgotten until the late ’90’s. That was when, responding to a clamor for “greener” vehicles, (mostly from California,) GM created the EV1. An unattractive blob, it was slow with a limited range. Sales were miniscule, but it might be argued this was also the dawn of the modern electric vehicle era.

Toyota launched the first generation Prius in 1997. Initially sold only in Japan, it reached the US in 2000 some months after the Honda Insight hybrid. It wasn’t an instant hit but dramatic rises in the price of gas saw car buyers take notice, and sales climbed.

A hybrid isn’t a pure electric vehicle as it carries a gasoline engine, but the growth of hybrids, along with legislation on gas mileage, stimulated interest in electrics. In 2008 Tesla started selling the electric-only Roadster. In 2010 Nissan gave us the all-electric Leaf, in 2012 Tesla launched the Model S, which was followed by BMW unveiling their i3.

The electric car is most definitely back and you won’t need carburetors, or fuel injectors.

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