I drive a 69 1000 Coupe. I had to change the spark plugs to B4s (previously B5s) cause they burnt out way too quickly, sounded like my car was miss firing. So i put optimax and flashlube in it now in stead of leaded fuel, and it feels like i've lost power. Any suggestions, would be appreciated.

Ta

try giving your car a full service going over the leads and change oil optimax did same 2 my ute and i just did a service and seem 2 pick up better! good luck!

I just had it serviced like a month ago, and then last week i changed the plugs and tuned it up a notch or 2 (or 3) and it went like crazy. Perhaps it was just the batch of fuel i had. It seemed alright when i put normal unleaded in it, but when i put optimax in it just went to ####.

advance timing to 10*or 11* advance.
back fire from carb is to lean,burnt valve or burnt head gasket.MITE HELP A BIT

Sounds like you got a bad batch of fuel. Have you put different fuel in since the optimax? Get rid of the optimax and just run normal unleaded. You shouldn't need any higher octane.

But if you ever do need it I recommend BP Ultimate over Optimax, as I've heard of people getting bad batches of optimax before.

By the way, what 1000 parts have you got? Don't have a bonnet do ya???

Tim

do NOT advance the timing more than 8deg. it will pink and kill your motor. ive got a worked 1200 running on av gas and its only on 7-9degs. no need to go higher.

Query the fuel quality.
The Porsche Club have had all sorts of trouble with Optimax and it may go so far as to involve damaged engines.
Also, the Datsun Roadster guys also has trouble a couple of years ago
Avgas is better if you are running more than 10 to 10.5 to 1 comp.

What is this avgas you speak of?

Excuse my ignorance.

Avgas is aviation fuel...available from airports in large quantities. Illegal for road use due to extremely high lead content.

I've heard that is anywhere up 110 octane

Does it make a difference if you your put more than the recommended amount of flashlube in your tank. Is it bad?