Engine misfiring

[dcajun]

I've read some old posts and will check the obvious, spark plugs, wires. Any other suggestions for
a misfire mainly while idling?

[pcolette]

Definitely check the timing.

[Jimm391730]

You need a strong spark, and check the float levels in the carbs.

[spandit]

Is there any way to find out definitely which cylinder is misbehaving? It's not spark (I'm using electronic ignition and the sparks will jump 3 inches - I've also run the engine with those little lights in-line with the plugs).

[Jimm391730]

You can try checking the exhaust manifold temperatures, either with a infrared thermometer ($40 at Harbor Freight) or with the "spit poppin' test" (a licked finger). I used to balance my two cylinder motorcycle that way. Colder temperatures mean that cylinder is not pulling it's weight.

[spandit]

How accurate are the IR thermometers? The one I'm looking at goes up to 550ºC or are the slightly cheaper ones adequate (i.e. how hot do exhaust manifolds get?)

[Pinzgauer Pete]

spandit they are extremely accurate and I was lucky enough to buy mine for 15.00 dollars. The actual exhaust temperture is not that critical and is not what you are really doing with the tool but rather you are measuring the difference between cylinders. If three are reading 375 degrees and one is reading 200 then you have a quick and easy test that just determined that one cylinder is not doing any work but merely along for the ride, that is all this tool will be useful for in this situation.

[spandit]

Thanks, Pete, didn't realise they were so cheap. Hoping it arrives tomorrow.

Out of interest, what kind of range will yours read at - what happens if you point it at the sun?

[audiocontr]

Bad things man. Bad things.

[edzz]

Out of interest, what kind of range will yours read at - what happens if you point it at the sun?

If you point it at the sun it will suck all the heat out of the sun and we will all freeze. I read it on the internet…

[spandit]

Out of interest, what kind of range will yours read at - what happens if you point it at the sun?

If you point it at the sun it will suck all the heat out of the sun and we will all freeze. I read it on the internet…

Must be true then! If you all Paypal me $1,000,000 I won't destroy the sun

[undysworld]

Must be true then! If you all Paypal me $1,000,000 I won't destroy the sun

Spandit

$1,000,000 paypal sent. It's still dark here. WTFO? Are there two such IR thermometers?

Oh wait, it's still 6:30am. No wonder.

[edzz]

Out of interest, what kind of range will yours read at - what happens if you point it at the sun?

If you point it at the sun it will suck all the heat out of the sun and we will all freeze. I read it on the internet…

Must be true then! If you all Paypal me $1,000,000 I won't destroy the sun

Upon closer study it is revealed that it will only suck enough heat from the sun to fry the thermometer and burn the hand holding it to charcoal thereby causing it to fall off. Sorry bout the hand Robin.

[David Dunn]

Upon closer study it is revealed that it will only suck enough heat from the sun to fry the thermometer and burn the hand holding it to charcoal thereby causing it to fall off. Sorry bout the hand Robin.

Look at the good side... he won't go blind!

[edzz]

Upon closer study it is revealed that it will only suck enough heat from the sun to fry the thermometer and burn the hand holding it to charcoal thereby causing it to fall off. Sorry bout the hand Robin.

Look at the good side... he won't go blind!

:?: Dave, do you really expect he would be holding the thermometer with both hands?