I have a 73 2.0 carbed and it starts fine when cold, but when it gets warmed up and you turn it off and then start it minutes later, it turns over for a while then finally starts slowly. Could it be vapor lock, how do I fix this problem?

QUOTE (Gearren @ Apr 18 2005, 06:28 PM)

I have a 73 2.0 carbed and it starts fine when cold, but when it gets warmed up and you turn it off and then start it minutes later, it turns over for a while then finally starts slowly.  Could it be vapor lock, how do I fix this problem?

it is *probably* not vapor lock.

probably, it is the fuel in your float bowls boiling out by being in a hot engine compartment attached to hot heads by two short aluminum manifolds.

do you have any Bakelite or phenolic heat insulator blociks between the manifolds and heads, or between the manifolds and carbs ? it's pretty important, especially nowadays that the fuel is so volatile.

there's an anti-percolation mod used on the /6's carbs but i don't know if it's possible, or useful, on the 2-throat carbs.

if your fuel pump comes on with the key, it could help to turn on the key and wait a few seconds for the bowls to fill, then do the "hot start" technique - accel pedal flat to the floor, close slowly as you crank, let it back when the engine catches.

but it coudn't hurt to check to make sure your lines are not located right next to hot stuff, like heat exchangers and flapper boxes and such. the factory location for the early cars' pump was right where the HE dump valve exhausted hot air ...

Where can I buy this insulating material, and what exactly do I put it on?

QUOTE (Gearren @ Apr 18 2005, 07:26 PM)

Where can I buy this insulating material, and what exactly do I put it on?

hard to say, because you didn't elaborate on what kind of carb(s) you have. there are factory blocks for the triple-throat Webers; i don't know if the manifold sizes are comparable. if you have Webers or Dellortos, i'd probably try contacting some place like CB Performance to see if they have premade insulator blocks. i have no doubt they'll know what you're talking about.

i don't recall where they are installed on the 6's -- i'm thinking between the manifold and the carb (it's a good thing for vaporisation for the manifold to be hot, but it's not good for the carb to be hot...)

You got a 2 liter 4 cyl? I believe they are the same as the FI phenolics.

You can use the stock "phenolic blocks" (plastic spacers between the head and the intake runner pipes) with carb manifolds. That should help with the heat transfer issue.

Don't know if that is really your problem, though... But it can't hurt (much) to try it out!

--DD