Offy tri-power stalls when in gear

Yeah that's a problem. Like was said, I'd try and get it set up to have the throttle fully closed @ idle on the outside carbs and idle off the center. You can't do that if they are hanging up before they close. Looks like they're are alot of springs and wires in there to try and get it to come down, that can present it's own problems like stiff throttle or foot fatigue cruising on the highway. Do you know what cam is installed in the engine? Your low vacuum is probably b/c you can't cut the airflow through the carbs. It looks like you need longer arms on the carbs to clear the manifold or correct the geometry, at least at the center carb.
 
One thing you may want to check is the throttle plates edges and how they seat. When I set mine up the outer cabs did not seat well enough and I got enough air through them to mess things up. I touched them up with some very fine emery cloth and was good to go. Also I would get a carb synchronizer, then you will be able to see what’s going on with each carb.
 
Econoline":1ujubwkd said:
Yeah that's a problem. Like was said, I'd try and get it set up to have the throttle fully closed @ idle on the outside carbs and idle off the center. You can't do that if they are hanging up before they close. Looks like they're are alot of springs and wires in there to try and get it to come down, that can present it's own problems like stiff throttle or foot fatigue cruising on the highway. Do you know what cam is installed in the engine? Your low vacuum is probably b/c you can't cut the airflow through the carbs. It looks like you need longer arms on the carbs to clear the manifold or correct the geometry, at least at the center carb.


Agree. Planning on grinding in some relief and setting it up as you suggested .
I'm not positive, but am pretty sure the cam is from Clifford. I think they only offer one for this engine.

.206 @ .050, .474 Int/Exh Valve lift w/ 1.6 rocker ratio, 110 lobe centers

Question - several members have mentioned about using a carb sync tool. If I'm going to purposely set them up differently (idle off center, outers closed) what would I be using the tool for? Sealing of throttle plates?
 
AFTER
getting that ctr set, concentrate on that
they're throwin U off (4 now).

(Later U can make up ur own "3 equal length tubes"
or use some bottles or spend on a syncro tool).
 
thegreyghost":1rrv6kgr said:
So I got a little bit more info to share. I started out to check the rpm's and dwell and compare them to bubba22349 numbers. Once I hooked up the tach I notices I was around 1100 at idle. When I went to turn it down I backed all three idle screw stops out and I couldn't get it to drop below 1000. That's when I noticed that the cam on the carb is actually contacting the Offy manifold on the first two carbs and not allowing them to close completely.

Should i be running a small spacer between the carb and the manifold ?

It did quickly check the combined dwell while I had things hooked up - looked pretty steady at 36.

KhWXiYF.jpg


More to come as I get some free time.

One again, thanks for all the help.

Yes for sure you need to be getting the idle RPM down to a more reasonable rate. Looks like will be an easy fix by using some type of spacer to get your throdle arm clearance so they don't drag or stick. A phenolic spacer if you can find them or some make their own out of plastic cutting boards, another way is the mid to late 1970's carb base gaskets that are made much thicker then the early gaskets and of corse you could stack severial base gaskets too. As far as the carb sync. Tool never use them as I am old school, with the progressive linkage if you had one you could only use it to sync the two end carb's. Good luck (y) :nod:
 
I use the sync tool to set the idle on the three carbs together. If you shut down the outer carbs completely you end up with the outer cylinders lean and inner cylinders rich. By balancing the three I find you get a much smoother and lower idle speed.
 
Yeah I am not talking about shuting down or blocking off the end carb's the idle gets tuned on all of them togeather. Being old school I just use a tach / dewel meter for this tuning. But before any type of tuning you would do be it with a sync. tool or any other method you first need to get the throdle blades were they aren't being held to far open or blocked from closing as is clearl indicated in the OP's above picture. Good luck (y) :nod:
 
The way I see it you don't need the outside carbs for idling more than a hair maybe, it's no worse than stock. And it's idling after all, you don't need much. I'd assume you'd want to tip in the outside carbs starting around 1000-1500 rpm. Trying to dial that in with all carbs idling sounds like a nightmare to me but I've never had a tri power setup so I'll defer to those with experience with that setup.
 
Setting up a tri-power setup can drive you nuts.
Steps I’ve taken to get mine working / didn’t run well in the beginning
Blocked off both outer cabs to find vacuum leak / found leak between log and manifold using carb cleaner as a detector
Replaced outer carbs / couldn’t get it to idle right / used carb sync and found that outer carb did close completely / cleaned up throttle plate edges
After finally getting it idling right moved on to jetting the carbs/ trial and error at the track
Installed O2 sensor and fine tuned a/f ratio
In general I think the biggest problem I’ve had is finding vacuum leaks.

Hope this helps some
 
O.K. Little bit more success tonight. Only had a couple minutes to play around, but got clearance for the carb linkage. Set idle around 850 rpm and checked the dwell. Only had 31 combined dwell - so I might have to adjust that slightly.

Car did stay running in all gears without issue so that's a plus.

Hopefully I'll have some time this weekend to play around a little more.

Once again, thanks for all the help and suggestions.
 
keep talkin,
less than 1/4 there ...
 
no, no, sorry~
"Bad chad" :nono:
I'm just tryin to stress the wrk on that middle
first'n foremost...
No longer stalls when placed in 'D', count the successes.

Think the harmonic balancer's twiqued out? Rubber inside's slipped, so timing mrks off?
:unsure:
 
chad":2gk3sre5 said:
no, no, sorry~
"Bad chad" :nono:
I'm just tryin to stress the wrk on that middle
first'n foremost...
No longer stalls when placed in 'D', count the successes.

Think the harmonic balancer's twiqued out? Rubber inside's slipped, so timing mrks off?
:unsure:

Ha! Not sure on the harmonic balancer yet. It doesn't seem to be drifting, but I need to pull number 1 and see if it's correct. Working most of the weekend, but I'll find some time to squeeze some fun in.

More to come.
 
Well, I feel like I took a step or two back right now.

Verified the harmonic dampner is showing the correct timing mark - It is.

Warmed the car up and decided since it's kinda nice out I would see if actually drives. It does, but not very well. Engine is very doggy yet and doesn't respond that well to the throttle. Doesn't cough or fall on it's face, just doesn't pick up and go. Just took it up the road and back returned to the garage and thought I'd check the timing. Now I have all the carbs closed and I can't get it to idle down. Running like 2000 rpm with all the carbs closed. Judging by the smell of my clothes, I'd say it's running very rich, but not sure at this point. If i close the mixture screws on the carb it begins to sputter.

**** I realized today that I always been around 1500 or more on the tach I'm using. I was reading the wrong scale when I thought i was around 850 - 900. I have a different tach i plan on hooking up. I never used this meter before and it seems to be displaying a much higher value than what my ear is detecting. I'm hooked up to the coil, the dual points wouldn't be screwing me up would they ? ****

No idea what's happening now, but after the drive I noticed it coming in and out of gear and realized the transmission is low on fluid. Since i need to go pick some up, figured it was a good time to take a break.
 
:unsure: Wow that idle RPM is way too high if you can't get this down you might need to disconnect the two end carb's or block them off. Start working on your tune up specs by first getting the gap of your spark plugs to .034, then it's important to set the point dwell correctly so that each one is to specs in above post 29 degrees and then check the total dwell is in the correct range of 34 to 37 degrees. Next set your base timing to 12 dergees BTDC. After you have these settings right then your are ready to work on the carb's. Again with this high of an idle RPM there is no way you are going to be able to tune the idle mixture. As a base setting on the carb mixture screws they are set to 3/4 to a max of 1 1/2 turns out. If you haven moved them yet count how many turns it takes to lightly bottom them out. Good luck (y) :nod:
 
Hi, set up the points first, one or both sets are off. You may as well put a tiny dab of white grease on the distributor cam.
The old saying is " dwell affects timing, but timing does not affect dwell."
Then see if the carbs are not closing.
With the progressive linkage the outer carbs should be closed tight until the center carb linkage stops reach the outer carb throttle shaft lever.
If you work the lever on each outer carb ( engine off) does the throttle snap closed?
Otherwise keep checking for a vacuum leak.
As mentioned, your tach and dwell may have an RPM selector button.
Good luck
 
yes ign tune 1st
then
carb (& again wrk that middle 1st).
As a-new-to-U vehicle U start at the beginning to
ck everything (trust not till verified). The HB is on...
(here's hopin U don't hafts open timing cover). Dizzy
('stabbed') lined up right...
 
bubba22349":2i4kzyxc said:
:unsure: Wow that idle RPM is way too high if you can't get this down you might need to disconnect the two end carb's or block them off. Start working on your tune up specs by first getting the gap of your spark plugs to .034, then it's important to set the point dwell correctly so that each one is to specs in above post 29 degrees and then check the total dwell is in the correct range of 34 to 37 degrees. Next set your base timing to 12 dergees BTDC. After you have these settings right then your are ready to work on the carb's. Again with this high of an idle RPM there is no way you are going to be able to tune the idle mixture. As a base setting on the carb mixture screws they are set to 3/4 to a max of 1 1/2 turns out. If you haven moved them yet count how many turns it takes to lightly bottom them out. Good luck (y) :nod:

I'm not sure I believe my antique tach / dwell meter. The engine doesn't sound anywhere close to 2000 rpm. However, whatever it is at, I can't get it any lower and that's a problem. I'm going to take your suggested starting points and reset everything this week. Re-check all my measurements and use a different tach. Starting with the center carb only and going from there.

I was starting to like this old meter, but maybe it's time for a new one.
nXNXzsyh.jpg


On a separate note. My # 1 plug looked a little rich when I pulled them.
5rI2dqTh.jpg
 
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