Zenith Accelerator Pump Assy

[bazookajoe]

Im looking for a source for the accelerator pump assembly that is activated by the diaphragm. It is located under the diaphragm cover. I have 10 old carbs that the little nipple on the accelerator pump valve does not protrude so the diaphragm cant open it to allow gas to flow through upon acceleration. Any thoughts on a source or why the little nipple is now below flush is on these valves?

[fowlercal]

Joe,

Check out Norfar.com
They sell the original carbs and parts kits (new manufacture). The M-151 kits are part K2167. They have raised their prices I see.
If you don’t see it on their website, they still answer the phone, like in the old days.

Good luck, Cal

[muttguru]

Joe....

look at the carbs and check the model number. If the carbs are 13841 models....then that recessed valve may be correct.

Let us know what you find.
Ken

[bazookajoe]

Not one of the carbs have that number and i dont think the diaphragm has enough push to overcome the spring in that valve to squirt gas into the carb throat. I can easily see the other style is opened by the diaphragm pushing on that nipple and opening the valve. Vaccuum would be the same in all these zenith carbs.

[bazookajoe]

All of the carbs i have have the recessed nipple style power valve. When i rebuild a carb i never have issues with the other style valve. Why is there two style valves anyway??

[rickf]

The accelerator pump will push gas into the jet regardless of the type of valve as the diaphragm compresses. It is when the diaphragm is fully compressed that the power valve is held open. I have only run into two of those recessed valves and I did not reuse them. I see nothing in the blueprints about a different valve so I am also curious.

[muttguru]

Joe and Rick.......
remember our friend the ex-Uk forces guy who now lives in Vietnam? His user name was Johnfal and he was involved in a discussion about the merits and drawbacks of the various models of M151-series carbs.

He was the first one (as far as I can remember) who pointed out that the 13841 carb is the one with the non-protruding power-valve, which he said was not interchangeable with other models' power-valves.

If you go here.....you can see what he says....he also lists the specs of various carb parts.

viewtopic.php?f=3&t=6540&p=53608&hilit= ... arb#p53608

Ken

[rickf]

Ok, Here is that info from Jons post copied here, But I have to wonder where he got most of that info. I have the blueprints for those carbs and some of the info does not jive and other does not exist. What is a "inlet fuel jet" ? I am going to look tomorrow but I am pretty sure the inlet seat is substantially bigger than the main jet.

Main jet - 30 (1.5mm),
Inlet Fuel Jet - 30 (1.5mm),
Idle Jet - 0.5mm,
Acceleration Jet - 0.5mm, not interchangeable with 13660 series, don't know about 12848.
Power valve - Pinless (valve appears to operate by pressure not mechanical contact with the diagphram),
Balance port in Power Valve - 0.4mm,
Diaphram - Large centre boss type, larger diameter thicker spring,
Emusion tube stand off from metal (no gasket) - 43mm,
Float (valve closed) - 5mm from gasket, float (valve open) - 18mm from gasket,

On a 13660B I opened the differences were:- Â
Idle Jet - 0.8mm,
Accleration Jet - 1.2mm,
Power valve - Pin type mechanically opened by diagphram,
Diagphram - Small centre boss type with narrower, thinner spring.