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TR2/3/3A Please help w this tuneup

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deuce

deuce

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Hello all.. I have a 1960 tr3. Been rebuilding it for 9+ years. It's ready except I can't get it to run right. The thing will hardly idle and when I give it some gas it coughs and spits and tries to stall.. all technical terms. It will start readily enough w full choke and the engine will accelerate reasonably with half choke but less than that..extreme hesitation. Since it seems to run better with choke I figured it was too lean so I have been enrichening <sp> the mixture one flat at a time with the adjustment nut on the bottom of the carbs. So far to no avail. The timing is set at 10 degrees btdc at idle. carbs were restored by a very reputable outfit. Don't know if I can name names on this forum... same with the engine and distributor. Ideas please. I would rather figure it out myself..with your help.. than take it to a Triumph guy for (x) dollars. Thanks in advance.. George
 
It would be helpful if you let us know what you have done.

On a new engine, it's best to adjust the valves, static time to about 5 degrees, and open the carb jets about two turns. With that, it should run well enough to warm it up and get started on the adjustments. If that's not happening, look around for an air leak. They can be hard to find.

Once it's warm, be sure that the valves and ignition timing are right first, then do the carbs.
 
I would suggest to start
remove air cleaners and check carb pistons for free movement with drop click test.If that is ok lift pistons and view fuel level in the jets.Level should be slightly below jet topsand jets should be at the same level for both carbs,If this is ok no need to touch float bowls.If not it will tell you which float bowl level needs attention.Also look down the carb bore and see that the throttle plates are fully closed,just start to move at the same time, and open fully.
Have fun
Tom
 
Getting the jetting "right" is something that takes a good mechanic some time. as there are
many different needle profiles.
As stated, first make sure the fuel level at the ventury bridge is just lower than the top of the bridge
It AND the jet should be 2mm lower at this point. Next look at the needle where it is in the piston.There is
a little shoulder that should be flush with the bottom of the piston. If you see too much shoulder , loosen
the set screw and adjust it upwards. Final adjustments are done by the nut holding the jet height.
There must be some good video on this some where.
Mad dog
 
Quick checks:

1) timing 3 degrees static. This can be set by putting the crank right on 3 deg BTDC, break the dizzy wire connection and put a light between the dizzy wires you broke, and turn the dizzy until the light just comes on. 10 degrees may be good at idle, but it depends if you are setting the proper 5-700 rpm, which I bet you have not gotten to yet. So for now count on static timing numbers.
2) Remove the air filters and look at your needles where they enter the jets. Pump up the fuel pump and check that you can see fuel about 1/8-1/16" below the top of the jets. If you cannot see fuel (which I suspect), then set your float levels higher until you do see fuel in the top of the jet.
3) Once running, spray ether starting fluid all around the carbs and intake manifold. If you get an increase in rpm, then you have found a vacuum leak that needs fixing.
4) Set both mixture nuts at 2 flats open. Make sure the pistons settle easily to be sure the jets are centered. Once running, always adjust the carb flats together...same setting for both. If you split the settings, you quickly get the engine running off one carb and it will never run right.
5) Balance the carbs at a 700rpm idle, as you fine tune the mixture nuts. If you get to 1000rpm at idle, you are bypassing the idle circuit and the mixture nuts don't do much.

Of course, after a good run to temp and back down, reset your valves and torque the heads. Have fun!
 
Careful with ether around a running engine. If the ether cloud combusts while you are inhaling the burns to the lungs will be serious to fatal.
Other aerosols will change rpm where leaks are present. I never thought of, nor would I have credited, this risk until it killed a man named Steve Torcise in Homestead, FL a few years back.
Bob
 
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Thank you all for the ideas. I am confident on the reconstruction of my parts. I didn't skimp. The engine didn't sit. That is one of the first things i read when I started this project. The engine, tranny, etc. can wait. Timing is another thing. Mark Macy says 4 degrees, Sarastro says 5, the bag of old distributor parts I got back from Advanced says 14-18 and the guy that helped me with mine said he sets his at 10 btdc. Can anyone clear that up for me? I do think the float level in both carbs was low. I adjusted that forked thingamabob to the factory recommended 7/16 under those fingers. I will wait for the gas fumes to clear before I start it again. Note to myself.. Always reinstall the float ..it will leak badly🔥
 
Another rookie question.. The factory manual says 7/16 under those fingers..which way raises the float level.. 3/8 or 1/2 inch?
 
bobhustead said:
Careful with ether around a running engine. If the ether cloud combusts while you are inhaling the burns to the lungs will be serious to fatal.
Other aerosols will change rpm where leaks are present. I never thought of, nor would I have credited, this risk until it killed a man named Steve Torcise in Homestead, FL a few years back.
Bob
Click to expand...
How about propane from a torch?
 
If your distributor is stock, then 3 is by the manual at static setting, but +- 2 will not affect it. The other settings you have are for modified distributors. If yours is modified, set timing as they recommended.

if not ether, then anything flammable…carb cleaner, brake cleaner, etc.

it’s been a long time, but I believe 3/8” would be in the direction of a higher float/fuel level.
 
The float , ultimately MUST keep the fuel LEVEL with the top of the jet, 2mm below
the bridge to make the "venturi" effect do its magic and mix gas/air. With the pistons out
you can see it easily. Adjust floats to make this happen.
Mad dog
 
Are the clamps tight that hold the 2 carbs together so they can work in unison?

Set the timing around 4 degree with timing light. It is difficult to see the timing marks with engine running and the pulley is not calibrated so about a 1/4 down the pulley is 4 degree. There is a small viewing point on the carb side where you can see the timing marks with the engine running on the pulleys. The view space is very small to see the timing marks and you will need to get the timing light just so--- down next to the fan belt to see the marks.

The engine should run ok at TDC but will run better advanced a couple of degrees. Set the dwell first at about 15 with a feeler gauge. You will hear the engine idle go up or down as you move the timing. if you can, move the little knurled nut to advanced or retard if possible. If not you will need to loosen the dizzy and center the knurled the nut or just move the dizzy to change the timing.

These engines will fowl out spark plugs quickly as you try and set the timing and fuel air fix, so have a few set of plugs on hand.

Steve
 
In my experience, the engine will run OK over a wide range of initial timing. If your engine will only run with half choke, AND it is thoroughly warmed up, something more than timing is the problem. Requiring choke when you shouldn't need it is a primary symptom or an air leak. No point in tuning carbs until you are SURE that there is no leak.
 
Hello..I went over the whole intake system with a propane torch with no apparent leaks. I'm not a master and this has me about down. I am this far (thumb and forefinger pinched together) from just taken it to a mechanic..letting them fix it ..but not learn a darn thing. It beat me and I hate that. Thanks for the reply
 
Well, as I re-read your initial post, a bad valve seal ( or over-tight valve lash) could be the culprit. Have you run a compression check?
 
CJD said:
Well, as I re-read your initial post, a bad valve seal ( or over-tight valve lash) could be the culprit. Have you run a compression check?
Click to expand...
I have not.. but.. why not? I'll go to my friendly neighborhood and see what they have in a compression gauge
 
You will figure this out here better than shops.

Set the lifts first-- I think that is the only place where something could do engine damage if not correct. Once the valves are lifters are all spinning at .010 the rest is easy it just takes some understanding of how and when to set the other settings

I would move to the dwell and timing next.

Naturally new plugs set a .25 I have all the plugs out so the motor spins easy.

Steve
 
if this is your first start up, I believe your problem is in the distributor placement it is off a tooth and when you pull the choke you move up the timing and fuel so the car runs. Line up the marks on the pulley and block at TDC compression stroke then carefully lift up the cap and see where the rotor is at when pointing at # 1. ask me how i know
Steve
 
Check for vacuum leaks and make sure the carb pistons aren't sticking. Also, check the fuel pump and the points/condenser in the distributor.
 
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