Please educate me on 727 throttle pressure. (I have no kickdown)

[YY1]

How much adjustment is left?

How much difference is there in the location of the old carb mounting point and the new?

Again- WAY better to have kickdown on too early, than have no pressure in the trans.

 

[toolmanmike]

How much adjustment is left?

How much difference is there in the location of the old carb mounting point and the new?

Again- WAY better to have kickdown on too early, than have no pressure in the trans.

Absolutely. Full throttle and keep it there and I bet there is some travel left at the transmission.

 

[Jonas Nordstrom]

How much adjustment is left?

How much difference is there in the location of the old carb mounting point and the new?

Again- WAY better to have kickdown on too early, than have no pressure in the trans.

Mounting point differs 1cm.

I checked again and when carb is fully open then the KD is bottomed out.
(Also checked with pedal floored.)

 

[YY1]

'nuther kinda simple question-

Have you driven it? IE is it actually kicking down?

You could always put the old carb back on and see if it operates properly.
If it doesn't, that suggests something else happened.

 

[Jonas Nordstrom]

'nuther kinda simple question-

Have you driven it? IE is it actually kicking down?

You could always put the old carb back on and see if it operates properly.
If it doesn't, that suggests something else happened.

It is kicking down but with a loooong delay when you really force it.

Yeah, it is tempting to put on the old carb and take notes.

 

[Geoff 2]

Jonas,
What are experiencing is 'ratio creep' [ for want of a better term ].
You change carbs [ TQ looks great, like King-Kong ]. You adjust the lever for best upshift. Now no lick down. However one carb may need less [ or more ] throttle movement to achieve the desired shift speed; also, the distance from the carb primary shaft to the cable pin can differ between brands.
So you have these variables in the KD lever system that affects shift points. You may have to get different levers, drill new holes etc to get it right.

 

[Jonas Nordstrom]

Jonas,
What are experiencing is 'ratio creep' [ for want of a better term ].
You change carbs [ TQ looks great, like King-Kong ]. You adjust the lever for best upshift. Now no lick down. However one carb may need less [ or more ] throttle movement to achieve the desired shift speed; also, the distance from the carb primary shaft to the cable pin can differ between brands.
So you have these variables in the KD lever system that affects shift points. You may have to get different levers, drill new holes etc to get it right.

Good point, the lever was not changed but the TQ has longer travel than the SD.

I do have some different lengths levers to play around with.
So, am I correct now to think that the lever should be longer to follow the longer range TQ?

 

[dvw]

If the lever is trully back all the way ay WOT and it doesn't kick down? The problem is not the linkage. It's lack of throttle pressure. Like stated before. Put a pressure gauge on it. If it's not above 90 psi with the lever moved all the way back you have an internal issue.
Doug

 

[1STMP]

While I'm a complete novice
on the workings of a 727,
I had the exact same
instance occur on a brand
new '76 727HP rebuild.
I run a Winters Sidewinder
cable shifter.
The trans would not kick
down no matter the cable
adjustment, no matter the
lever length. (Got one with
3 different holes drilled in it)
I finally reached my wits end
and drove it to an old timer
who cut his teeth on Mopar.
This may not be your case,
but as far as I could grasp
his explanation, cables do
not have the strength to
push the lever far enough
forward.
He cut a medium strength
spring to length that pulls
the lever to full forward.
There's even a location on
the trans case to attach it.
I've got passing gear that
scares me sometimes. Oh,
what a feeling!

 

[Jonas Nordstrom]

While I'm a complete novice
on the workings of a 727,
I had the exact same
instance occur on a brand
new '76 727HP rebuild.
I run a Winters Sidewinder
cable shifter.
The trans would not kick
down no matter the cable
adjustment, no matter the
lever length. (Got one with
3 different holes drilled in it)
I finally reached my wits end
and drove it to an old timer
who cut his teeth on Mopar.
This may not be your case,
but as far as I could grasp
his explanation, cables do
not have the strength to
push the lever far enough
forward.
He cut a medium strength
spring to length that pulls
the lever to full forward.
There's even a location on
the trans case to attach it.
I've got passing gear that
scares me sometimes. Oh,
what a feeling!

Thanks for the info and I do have a spring pulling the arm forward.

 

[1STMP]

Thanks for the info and I do have a spring pulling the arm

Not to familiar with your
carb. Is there any way to
adjust the vacuum diaphram
to a lighter setting?
Quickfuel made this easy
with just a single screw
adjustment, where the
Holley's had us changing
out different springs.

 

[Jonas Nordstrom]

Sure is.
....but how would a quicker flow to the secondary's help my kickdown?
Carb is already perfectly tuned in for the transition to the secondary's.

 

[Jonas Nordstrom]

The OP has a 2 barrel throttle bracket and kickdown linkage with a 4 barrel.

Fix that issue and adjust properly, and I'd bet the problem goes away.

...unless he's already burned up the band/clutches.

What do you mean?
The throttle bracket is custom made and pulls the full length of the carbs throttle travel.
The kickdown linkage is adjusted correctly for when the gears should fall in and there is no slippage.

 

[YY1]

What do you mean?
The throttle bracket is custom made and pulls the full length of the carbs throttle travel.
The kickdown linkage is adjusted correctly for when the gears should fall in and there is no slippage.

OOps, sorry I confused this thread with the other guy having a similar issue.

I'll delete my previous post.

 

[68 Sport Satellite]

While I'm a complete novice
on the workings of a 727,
I had the exact same
instance occur on a brand
new '76 727HP rebuild.
I run a Winters Sidewinder
cable shifter.
The trans would not kick
down no matter the cable
adjustment, no matter the
lever length. (Got one with
3 different holes drilled in it)
I finally reached my wits end
and drove it to an old timer
who cut his teeth on Mopar.
This may not be your case,
but as far as I could grasp
his explanation, cables do
not have the strength to
push the lever far enough
forward.
He cut a medium strength
spring to length that pulls
the lever to full forward.
There's even a location on
the trans case to attach it.
I've got passing gear that
scares me sometimes. Oh,
what a feeling!

any chance you can post a few photos of this? I'm surprised a spring would work better than a cable. Both stretch a bit don't they?

 

[68 Sport Satellite]

I chased this issue for over a year with off and on driving on my brand new Cope Racing 727 with partial throttle kickdown and Bouchillon cable with Quickfuel 735 carb. It was so frustrating. In the end I was not engaging the Bouchillon cable carb attachment point throw deep enough. I did have full travel at WOT, but it would only kick down at WOT and not at partial. So I finally pulled the cable to move the carb lever back and start to engage the spring resistance a good 1/2" and locked it in. I then had partial throttle kick down. Before I was stopping where I set it when I felt some initial resistance with carb at idle. For my setup that turned out to be wrong. There is some range of adjustment from once you hit the initial carb side wire engagement with the spring pushing back. I think this a spring in the carb itself (others please correct me if I'm wrong). The other thing to remember is that the cable may stretch a bit compared to when it was new. Make sure all the slack is taken out and forget your old clamp point. Lock that sucker in. Make sure to partially engage that spring (but not so it revs at idle).

 

[68 Sport Satellite]

Mounting point differs 1cm.

I checked again and when carb is fully open then the KD is bottomed out.
(Also checked with pedal floored.)

View attachment 1631357

I'm no expert, but shouldn't your return springs be connected to the lower hole in front of the cable attachment shown in your photo? Not that this is contributing to your issue. That's the same cable I have on my car. Let's see a photo of your cable clamp. Lock it in and use a blue or purple sharpie to mark it on the the clamp so you can see if it's slipping when you push the accelerator. That thing needs to be pulled back hard towards the firewall to engage the spring (not to WOT) then lock it in good.

 

[Jonas Nordstrom]

any chance you can post a few photos of this? I'm surprised a spring would work better than a cable. Both stretch a bit don't they?

I guess he means the return spring?
Like on mine here:

 

[Jonas Nordstrom]

I'm no expert, but shouldn't your return springs be connected to the lower hole in front of the cable attachment shown in your photo? Not that this is contributing to your issue. That's the same cable I have on my car. Let's see a photo of your cable clamp. Lock it in and use a blue or purple sharpie to mark it on the the clamp so you can see if it's slipping when you push the accelerator. That thing needs to be pulled back hard towards the firewall to engage the spring (not to WOT) then lock it in good.

Return springs are connected at the throttle cable pin as they should be.
Kick down wire is clamped down hard and was marked with a black sharpie.

Interesting that you had to engage into the pressure a bit further than me.
When my carb is at idle the kickdown just hits the start of the pressure.

 

[68 Sport Satellite]

Return springs are connected at the throttle cable pin as they should be.
Kick down wire is clamped down hard and was marked with a black sharpie.

Interesting that you had to engage into the pressure a bit further than me.
When my carb is at idle the kickdown just hits the start of the pressure.

View attachment 1640296

View attachment 1640297

great photos, thanks. The bottom cable is the one I'm talking about moving back more, not the top one. That's my one gripe with this Bouchillon setup - I wish each cable could be locked down independently.