Club 80-90 Forums

Van still still has speed issue but thats okay for now just going to enjoy for now.

With the van stationary and revving it up from the engine bay if I rev it up really high it makes loud bangs like a misfire/backfire from the carbs, is this normal ? (obviously I don't hold it for very long like this !)

is this an Aircooled thing ?

No it's a timing/weak mixture/holed exhaust/poor compression thing

Probably the rev limiter cutting in.

This is not an Aircooled thing, it's a stupid thing to do for no reason. The engine's rattling around and trying to self destruct with any load on it!

Fell for it again.

no rev limiter on

i dont make a habit of it


fell for what again ?

Brief synopsis,

Bought van.

Van runs `well'

Won't go fast

Lots of diagnosis from many people

Lots of answers, no outcome

Not mechanically experienced with engines

Relates a new symptom

Going off on another tangent?

i was only asking a question out of curiosity maybe the lack of speed is related to the backfire...

another tangent me

sternal wrote:no rev limiter on

i dont make a habit of it


fell for what again ?

Valves bouncing?

Valves bouncing? whats that then ?

I downloaded google

Works for me.

Hello,

Aircooleds....

Loads of poetry...

but alas no magic....

This is a rebuilt CU with the carbs as they were set:

http://www.youtube.com/watch?v=4qayyc9Z4E0" onclick="window.open(this.href);return false;

and then this is it set up properly, Valves then Timing then Carburettors

(with old type ignition ,a SVDA distributor bought for £10 off a well known auction site)

http://www.youtube.com/watch?v=dsfo5ATgBp0" onclick="window.open(this.href);return false;

You do need all the test kit to do this yourself...

Hope this helps..

Cordialement,

have a read of this will give you some idea of what a weak mixture is
http://www.tech.plym.ac.uk/sme/ther305-web/Combust1.PDF" onclick="window.open(this.href);return false;

I thought you were getting the carbs rebuilt???????

If it's popping back through the carb surely that means the inlet valve is "open" during the combustion / power stroke? A weak mixture would only pop out of the exhaust wouldn't it? Unless the weak mixture had over-heated the engine enough to make the fuel ignite in the inlet without the need for a spark?

it will sneeze at the/in the carb if the manifold is loose

mark

BOXY wrote:

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loud bangs like a misfire/backfire from the carbs, 

If it's popping back through the carb surely that means the inlet valve is "open" during the combustion / power stroke? A weak mixture would only pop out of the exhaust wouldn't it? Unless the weak mixture had over-heated the engine enough to make the fuel ignite in the inlet without the need for a spark?