Frustrated Beyond Measure

MexicoMike · Oct 23, 2023

You have to start from the very beginning re troubleshooting. Ensure all the basics are correct - carbs/ignition system/timing/valve clearance. As noted, you may think you have all the carb passages clean but carb cleaner and air pressure is often not sufficient. Running something like a guitar string through all jets/passages is necessary and then carb cleaner/air pressure.

The way I look at any old vehicle with issues is to ask this question, "When the vehicle was new, did it have this problem?" The answer is usually, "No." IOW, changing parts to something different than OEM style parts is NOT A SOLUTION to a problem.

Richard Tool · Oct 23, 2023

Regarding ethanol - known issues are water absorption and attacking rubber ( and similar materials) components. That said I have not had any problems using it in my 72 750 Combat for 3 ( or is it 2 ? ) years / 3k miles or my 1950 ES2 for 10 years /3k miles .
I fill the tanks with Aviation gas for winter layup .
Am I just lucky ? Maybe but I’ll take it .

marshg246 · Oct 23, 2023

MexicoMike said:
... changing parts to something different than OEM style parts is NOT A SOLUTION to a problem.

Right, it's like what a doctor does. Generally speaking, they don't try to fix problems, they try to make symptoms go away. When you do that, you often cause another problem or problems.

In the early 70s I fixed copiers for a living. Guys would bend the arm on a switch to "correct" paper-feed timing errors. That did not fix the problem, it fixed one symptom and caused timing issues throughout the machine!

Deets55 · Oct 23, 2023

FWIW, do those brass slides have a cutaway number stamped on them? Would like to know if they were either a 3.0 or 3.5? Both should work, unless the brass ones are something completely different.

Onder · Oct 23, 2023

Because I like to torture myself, I regularly look at the Inflation Calculator. If a new Premier for a Trident cost 10.70 in 1968 that would be equal to the 228 pounds asking today. Anybody know what a new Amal cost then?

texasSlick · Oct 23, 2023

My approach has always been, go back to original configuration, then trouble shoot from there.

Slick

Schwany · Oct 23, 2023

marshg246 said:
Right, it's like what a doctor does. Generally speaking, they don't try to fix problems, they try to make symptoms go away. When you do that, you often cause another problem or problems.

In the early 70s I fixed copiers for a living. Guys would bend the arm on a switch to "correct" paper-feed timing errors. That did not fix the problem, it fixed one symptom and caused timing issues throughout the machine!

I'll pay a nickel on the dollar for all your TriSpark inventory since it apparently could cause problems cuz it's not OEM. Just trying to help.

Big_Jim59 · Oct 23, 2023

MexicoMike said:
You have to start from the very beginning re troubleshooting. Ensure all the basics are correct - carbs/ignition system/timing/valve clearance. As noted, you may think you have all the carb passages clean but carb cleaner and air pressure is often not sufficient. Running something like a guitar string through all jets/passages is necessary and then carb cleaner/air pressure.

The way I look at any old vehicle with issues is to ask this question, "When the vehicle was new, did it have this problem?" The answer is usually, "No." IOW, changing parts to something different than OEM style parts is NOT A SOLUTION to a problem.

As to the question, "When the vehicle was new, did it have this problem?" The answer is quite possibly yes. The carbs on my bike are possibly not the ones it left the factory with. Who knows these carbs came from? These units are take offs and might have been a problem from the beginning. They were probably replaced and passed along with possibly a piece of swarf in one of the passages. Most of the build quality mistakes have been rectified by now at the hands of dedicated riders but some still manage to raise their heads every now and then. But I get your point. If it had been built correctly, it would run great with the Amal concentrics and the points it came with. I think if money were no object I would opt for the Premiers just to have a good running twin carb Norton if nothing else.

marshg246 · Oct 23, 2023

Schwany said:
I'll pay a nickel on the dollar for all your TriSpark inventory since it apparently could cause problems cuz it's not OEM. Just trying to help.

You need to read what MexicoMike said and what I said again. I was simply talking about fixing symptoms instead of problems.

htown16 · Oct 23, 2023

I put a set of Wassels on a 71 750 and they performed just as well as the Premiers. Cosmetically not as nice a finish but about half the cost.
With a Pazon Surefire you should be strobing 28 at 2500 rpm and 31 when wound out past 4000.

johnm · Oct 23, 2023

At the risk of turning into an ethanol thread you may find success with the following.

Turn off the fuel tap and run the carb dry if yiu are leaving it over night or a few days.

If you leaving it a week or more do the above plus remove the airscrews carefully counting the turns and exact position. Blow carb cleaner through the air screw hole. Replace the airscrews in exactly the same place.

I do this with bikes run on methanol and it works well.

This does assume metal tanks. Don't leave tanks with ethanol over winter.

Schwany · Oct 23, 2023

marshg246 said:
You need to read what MexicoMike said and what I said again. I was simply talking about fixing symptoms instead of problems.

Gee-whiz Dad, do I have to?

Offer still stands. Good till midnight tonight.

worntorn · Oct 23, 2023

Richard Tool said:
Regarding ethanol - known issues are water absorption and attacking rubber ( and similar materials) components. That said I have not had any problems using it in my 72 750 Combat for 3 ( or is it 2 ? ) years / 3k miles or my 1950 ES2 for 10 years /3k miles .
I fill the tanks with Aviation gas for winter layup .
Am I just lucky ? Maybe but I’ll take it .

I don't think it's luck, it seems you are doing the right thing by using the Aviation fuel for winter lay up.
I have burned quite a bit of 5 and 10 percent ethanol fuel while out on tour, no problems so far. As long gets used up fairly quickly it doesn't seem to do carb damage.
Like you, I always make sure to load up on ethanol free and run that into the carbs before the bike gets parked.

A good friend was just given a very nice 34 Ford hotrod. The car was parked for six years with ethanol fuel in the tank and carb. The carb, all fuel lines and fuel tank had to be replaced.

Glen

Big_Jim59 · Oct 23, 2023

Carbs are coming back off maybe for good. I'll keep you all posted.

concours · Oct 23, 2023

Big_Jim59 said:
Carbs are coming back off maybe for good. I'll keep you all posted.

Bin them, bolt on some fresh Premiers & be done. No more "jackin' with it"

marshg246 · Oct 23, 2023

Onder said:
Because I like to torture myself, I regularly look at the Inflation Calculator. If a new Premier for a Trident cost 10.70 in 1968 that would be equal to the 228 pounds asking today. Anybody know what a new Amal cost then?

In 1966 a dual carb Triumph 500 cost 9 pounds more than a single carb model (monoblocs). In 1971 I bought a pair of new 600-series carbs from a Triumph dealer for less than $30 in Maryland. I seem to remember them being $10 - I know I only had $30/week to spend including lunches.

The Amal suggested retail for a PACK 124AL (Trident Premier Aluminum Set) is 638.11 GPB as of Oct 1, 2023 (212.70 each). Pretty sure that's without VAT.

So, it sounds like your numbers are about right. Of course, there were no Premier carbs back then and certainly no aluminum ones so with that in mind, they are a deal today (doesn't feel like it, does it?)

worntorn · Oct 23, 2023

Wow they have almost doubled in price in one year with the switch to aluminium.
As I recall, Burlen had the Premieres listed at 180 +- GBP ea and not available for about 1 year leading up to the AL. Premieres. That was for most of 2022, if I'm not mistaken. Could have been 2021, it's all going by quickly.
It is a rather fast doubling of cost, even in these inflationary times.

Fast Eddie · Oct 23, 2023

worntorn said:
Wow they have almost doubled in price in one year with the switch to aluminium.
As I recall, Burlen had the Premieres listed at 180 +- GBP ea and not available for about 1 year leading up to the AL. Premieres. That was for most of 2022, if I'm not mistaken. Could have been 2021, it's all going by quickly.
It is a rather fast doubling of cost, even in these inflationary times.

Greg mentioned the Trident pack, so three of ‘em… £212 each…

worntorn · Oct 23, 2023

Ah, right.
Yes I just had a look. The new al. Premieres are 200 gbp ea without VAT, so not so bad.
The standard type are shown at 115 GBP each but not currently available.

Fast Eddie · Oct 23, 2023

worntorn said:
Ah, right.
Yes I just had a look. The new al. Premieres are 200 gbp ea without VAT, so not so bad.
The standard type are shown at 113 GBP each but not currently available.

I agree, £200 for an aluminium bodied Premier carb isn’t so bad at all.

Lets not forget, we‘re bloody lucky to be able to buy brand new, better than original, carbs for these antiques we ride !

Frustrated Beyond Measure

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