Type IV carb question

[kerian159]

I am running a 2.0 litre motor with a 009 dist. And a weber progressive. The bus is running great until I go up a hill or floor it then it starts pinging a bit. Any advice would be nice. Thanks
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1976 Type II Westy P22

"Growing older, but not up!"

[Randy in Maine]

How do you have it timed?

[kerian159]

28 at 3000
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1976 Type II Westy P22

"Growing older, but not up!"

[bugsy95]

I would try and find a stock distributor and get rid of that 009.The bus runs a lot better.dave 1973 bus

[mygreenbus]

[Tuna Tim]

A few questions/answers to help the gallery cogitate:

Is this a behavior that has started recently?

Have you changed fuel grades or stations? Additives?

Has a different driver been putting miles on your ride?

Has your payload increased lately (more passengers, crates of gold bullion)?

Does the pinging have any relationship to outside air temperature?

Have you put new tires and/or wheels on the bus recently?

Any engine mods you would like to confess to?

How long since your last tune-up?
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1974 Bay
CSII
091
Dual 40 Dells
Unilite
Thunderbird Extractor

[rustybutterknife]

What is the compression ratio you're running in that engine Also what is the ambient temp in your area. Before pointing fingers at that dizzy, I would tune it up and adjust the carb esp. mixture or run a much higher octane fuel to test that theory.
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What, they don't sell purple locktite? Just mix the red and the blue together.

[udidwht]

How many miles on the motor? An excess amount of carbon build up can cause pinging.

[busman78]

Check that the ported vac outlet on the carb is plugged.

What size are the main, air correction jets and pump jet?

[kerian159]

Ok outside air temp. 70's ~ 80's driving home from birmingham bug blast. Tire's and engine - Stock for a '76 westy 2.0L all stock save 009 and weber progressive. How many miles on the engine no more than 200 when I started this last trip I had to redo the piston's and heads after blowing a hole in the top of a piston (had the timing way off) Octane running is 89 with lucas additive. It only pings when I going up a hill and trying to maintain speed. If I give it the rest of the carb (the other barrel) the pinging goes away. Last tune up umm saturday at the car show due to me not quite knowing what I was doing on adjusting the valves. Learn something new everyday Size of the jets have no clue is that something you can figure out by looking at the jets themselves?
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1976 Type II Westy P22

"Growing older, but not up!"

[busman78]

Yep, you have to pull the top to get the air correction, main and pump jet, for the idle they are screwed into the sides. You are lean, possibly the mains, possibly a little on idle jet depending on what rpm you are pinging at, the air correction may be too large causing the fuel well to be too low for fuel to be drawn down the throat at that particular rpm. Get the jet sizes.

Just out of curiosity is this the same carb set up on the engine you blew a piston?

[SGKent]

Your pinging probably isn't going away at WOT, it is probably just changing its character froma ping to a thud and that is why you destroyed your last pistons. You are either too high a compression, too low an octane or too advance timing. If you are using a variable timing light less than a snap on etc don't rely on the numbers on it to time the bus.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin