how to

[jetboat]

has any body out there ever had the problem of the new(2005)marine edlebrock carb,they have no provision for a vacume line to the dist.were else can a vacume line go from the carb?

[Wicked Performance Boats]

You don't need vaccum advance in a boat. Just set total timing. Budlight

[DelawareDave]

marine engines typically do not use "vacuum advance". The "vacuum advance" is designed to retard the ignition timing under heavy engine load to reduce spark knock. This function is self-defeating in a marine engine, as it is almost always under load.

[jetboat]

marine engines typically do not use "vacuum advance". The "vacuum advance" is designed to retard the ignition timing under heavy engine load to reduce spark knock. This function is self-defeating in a marine engine, as it is almost always under load.
what if its a electronic system,if the vacume is removed,doesent that send a false reading with advance and retard.ive have since this note to attatch a vacume line to the manifodld?iam still lost.

[Oldsquirt]

what if its a electronic system,if the vacume is removed,doesent that send a false reading with advance and retard.ive have since this note to attatch a vacume line to the manifodld?iam still lost.
What engine, boat and distributor do you have? As has been said, most boats don't use a vacuum advance.
On a typical Chevrolet distributor It does not retard the timing... It stops adding timing and you only get the mechanical advance...
Correct. The typical vacuum advance adds timing to the mechanical under light load, high manifold vacuum conditions, which you wont be seeing in a boat.
There are some auto manufacturers that have used vacuum retard, or a combination of vacuum retard and vacuum advance, but those applications are rare and all the ones I can think of are foreign cars.

[jetboat]

What engine, boat and distributor do you have? As has been said, most boats don't use a vacuum advance.
Correct. The typical vacuum advance adds timing to the mechanical under light load, high manifold vacuum conditions, which you wont be seeing in a boat.
There are some auto manufacturers that have used vacuum retard, or a combination of vacuum retard and vacuum advance, but those applications are rare and all the ones I can think of are foreign cars.
the system is for a ford 640 with out any msd.was tod when the vacume is removerd from the dist housing,first it has to be closed without anyl leaks.second it is not a mechinal dist(maybe it shuould be) how ever its what i have. or just maybe go back to the old point system.besides the engine is almost stock.or iam i missing the point.

[Oldsquirt]

the system is for a ford 460 with out any msd.was tod when the vacume is removerd from the dist housing,first it has to be closed without anyl leaks.second it is not a mechinal dist(maybe it shuould be) how ever its what i have. or just maybe go back to the old point system.besides the engine is almost stock.or iam i missing the point.
Without knowing exactly what distributor/ignition you are using, its hard to give a truly accurate answer. I rather suspect you DO have mechanical advance in the distributor, but there are some new full electronic systems out there.
Here is what I suggest. Although not needed, you can get a small vacuum cap at the parts store and put it on the port at the vacuum advance can.
Take a look at your harmonic balancer. Fords usually have a degreed balancer. Put a little white paint at the 10, 20 and 30 degree marks so they are easier to see. Step one, start the engine and check timing at idle and write that down. Step two, bring rpm up until the timing stops advancing. Record that timing number. The difference between the two is how much mechanical advance you have(i.e. 15 initial and 35 total gives you 20 mechanical in the distributor). Write that down for future reference, as well.
Not sure what the Ford guys are recommending for the total timing(measured in step 2) but I suspect it should be in the 34-36 degree range. When you subtract the mechanical in your distributor from that number it will give you the initial setting you need to use with that distributor.

[CARLSON-JET]

I didn't see anybody post that you Build in About 20 to 24 degrees on the the mechanical advance part. This way when you set your initial timing at 12 deg. you have a total of 32 to 36 total. I hope this might clear up your understanding jetboat.
Oldsquirt, My 69 pontiac had a funky set up that was part of the CCS (controled combustion system) emissions. it used a ported vacuum switch and a check valve. I don't remember all the details as it has long since been shelved neatly packed in a box. The PVS had 5 ports 2 being blocked. The pvs was controlled by water temps. It seemed like a redundant setup but I guess thats what the feds wanted. the book said it controlled the spark under cold, hot, idling, de-acceleration ect in different ways depending on temps and loads. All I know is it was not a cool looking set-up to a 16 yr old kid. Now that i'm almost 40 and have all the pieces, It is starting to look a little cooler.. R.B.

[jetboat]

I didn't see anybody post that you Build in About 20 to 24 degrees on the the mechanical advance part. This way when you set your initial timing at 12 deg. you have a total of 32 to 36 total. I hope this might clear up your understanding jetboat.
Oldsquirt, My 69 pontiac had a funky set up that was part of the CCS (controled combustion system) emissions. it used a ported vacuum switch and a check valve. I don't remember all the details as it has long since been shelved neatly packed in a box. The PVS had 5 ports 2 being blocked. The pvs was controlled by water temps. It seemed like a redundant setup but I guess thats what the feds wanted. the book said it controlled the spark under cold, hot, idling, de-acceleration ect in different ways depending on temps and loads. All I know is it was not a cool looking set-up to a 16 yr old kid. Now that i'm almost 40 and have all the pieces, It is starting to look a little cooler.. R.B.
thanks to all who responded.let you all know some time soon,after the boat is painted.

[Oldsquirt]

Oldsquirt, My 69 pontiac had a funky set up that was part of the CCS (controled combustion system) emissions. it used a ported vacuum switch and a check valve. I don't remember all the details as it has long since been shelved neatly packed in a box. The PVS had 5 ports 2 being blocked. The pvs was controlled by water temps. It seemed like a redundant setup but I guess thats what the feds wanted. the book said it controlled the spark under cold, hot, idling, de-acceleration ect in different ways depending on temps and loads. All I know is it was not a cool looking set-up to a 16 yr old kid. Now that i'm almost 40 and have all the pieces, It is starting to look a little cooler.. R.B.
Being a long time auto tech, I remember some of those goofy GM systems. Can't recall if any of them were designed to retard timing, just give varying amounts of vacuum advance depending on operating conditions. Seemed complicated at the time, not so compared to what we work on today. Good move saving that stuff.