Tuning (carb, timing, etc..) Question??

[Anonymous]

Thanks to TJ and Joe, I've finally got the 200 in my '66 Mustang running. I set the initial timing to 12* and in the driveway, it sounds nice. I began searching the forum and became overloaded with information, so here's some beginner questions..

First, this is a 200ci with 3-tranny. I've installed the Duraspark II with GM/HEI module and Ford/TFI coil. The carb is a H/W 5200 new/reman from Stovebolt with electric choke.

It seems to be idleing (sp?) a little low. I have to play with the throttle a little to get it to idle. I was able to set the intial timing to 12* (timing light), but I didn't have a tach to check the engine rpm.

Do I dial in the timing first, or adjust the carb first?? Can I truely set the timing if the idle is off? For that matter, can I dial in the idle without setting the timing first?

I'm picking up a tach this weekend to check the the timing curve, but is the stumbling at idle, a timing problem or an idle adjustment? From what I've read, I should set the inital timing at 900rpm. Does that sound correct?

So, my plan is to adjust the idle screw on the carb to get an idle at 900rpm. Then set the inital timing to around 12-14*. From there I'll check the timing curve and compare those numbers to others on the forum. Does this sound right?

I've read alot about re-jetting. Is this needed? The motor is stock, although I will go to a header and better exhaust in the future. I have no plans on doing anything else with this motor. I was hoping that the Stovebolt carb would be good out of the box, as I don't know anything about carbs.

Thanks in advance for any assistance..

brian

 

[pedal2themetal45]

Thanks to TJ and Joe, I've finally got the 200 in my '66 Mustang running. I set the initial timing to 12* and in the driveway, it sounds nice. I began searching the forum and became overloaded with information, so here's some beginner questions..

thats easy to do

First, this is a 200ci with 3-tranny. I've installed the Duraspark II with GM/HEI module and Ford/TFI coil. The carb is a H/W 5200 new/reman from Stovebolt with electric choke.

It seems to be idleing (sp?) a little low. I have to play with the throttle a little to get it to idle. I was able to set the intial timing to 12* (timing light), but I didn't have a tach to check the engine rpm.

Do I dial in the timing first, or adjust the carb first?? Can I truely set the timing if the idle is off? For that matter, can I dial in the idle without setting the timing first?
Timing is set at a spific (sp) idle speed so yes you would need to set the idle right first. then the timming , then readjust the idle, and recheck the timming. Idle speed will change the timming..

I'm picking up a tach this weekend to check the the timing curve, but is the stumbling at idle, a timing problem or an idle adjustment? From what I've read, I should set the inital timing at 900rpm. Does that sound correct?
yes most likely the stumbling could be the low idle. 900 is all full fast unless its an automatic and that idle is in Nutrial. other wise idle is 650 to 700 in Drive with an auto and the same for a sitck in nutrial

So, my plan is to adjust the idle screw on the carb to get an idle at 900rpm. Then set the inital timing to around 12-14*. From there I'll check the timing curve and compare those numbers to others on the forum. Does this sound right?
12-14* is not allways right it depends on you motor and what it wants you can start there.. Don't forget you well most likely need to set the fule mixture screw as well after the motor is warm and the timming is set...
Screw in base plate of carb is mixture screw.. turn it out to best idle (fastest),,, then turn it in just till the motor starts to slow down a little, back it out to best idle again, then in just a little 1/8 th of a turn maybe.. a little bit goes a long way with this screw this is a fine adjustment of carbs idle circurt

I've read alot about re-jetting. Is this needed? The motor is stock, although I will go to a header and better exhaust in the future. I have no plans on doing anything else with this motor. I was hoping that the Stovebolt carb would be good out of the box, as I don't know anything about carbs.
again this depends on what the motor wants you well have to see how it go's
good luck
tim

Thanks in advance for any assistance..

brian

 

[CZLN6]

Howdy Brian;

The timing and carb tuning go hand-in-hand. Setting initial advance timing at 12 BTDC with the engine idle speed below 900 rpms is a good place to start. Be sure to disconnect and plug the vacuum source from the carb before setting the initial advance. Depending on the internal centrifugal advance it should not be an issue with the engine idleing below 900. Personally, I'd set the idle as low as possible and the initial advance as high as possible with no knock.

There is a very good stickie at the top of this forum on tuning H/W 5200s. They are very seldom right as they come, but you could get lucky.

Good luck.

Adios, David

 

[Anonymous]

Thanks guys, I went back and looked at the sticky on the 5200 and...

all it did was confuse me more..

To start, which is the "idle speed" screw and which is the "idle mixture" screw? I wasn't clear from the diagram. Are the item numbers 57 and 58 in the diagram?

I'll start with that for now and leave my jets as is. After I have a chance to drive it, I may go back and mess with the jets, but for now, I'd just like it to idle nicely so that I can finish putting it together...

Thanks again for the help..

brian

 

[pedal2themetal45]

Hay Brian
Yes the digram is confusiing but #56 is the mixture screw (pointed screw) it well be in the base plate of the carb. and #58 looks to be the idle screw... it looks like its below the choke housing and operates both he idle and the fast idle.
the Digram does not co-inside with the parts listing chart... the chart shows 57 as idle screw but the digram shows 57 is a spring under an adjustment screw in the choke housing not the idlse screw. best I can tell.
adjust by my previous post reply..
tim

 

[Anonymous]

Thanks Tim, I'll play with it today and see what happens..

 

[Anonymous]

Outstanding!! Thanks Tim, everything worked like a charm and it wasn't nearly as scary as I thought it would be. It idles smooth and doesn't seem to have any problems when I bump the throttle. I'll have to road test it to make sure, but it seems like I may have gotten lucky with this carb out of the box..

Anyway, I compared my setup to the sticky and think that everything looks right. With the "best" idle,

My idle speed screw is about 1/2 turn out.
My mixture screw is about 1-1/2 turn out.

If I'm reading the posts and the Weber instruction sheet correctly, this is pretty close to ideal. I'm guessing from this, that my jets appear to be correct enough. Obviously a road test will tell me more.

My initial timing is set to 14* @ 600 rpm (standard tranny).
With the vaccuum connected, it comes all in at around 38* @ 2000 rpm.
My plugs are gapped to .045.

I haven't put a load on it yet to check for pinging, but I think that I remember these numbers being about right from previous posts..

Again, does this all look right? If anybody has any input, I'd appreciate it...

Thanks again to everyone that has helped..