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Discussion Starter #21
Put some Rislone in the oil. If something is plugged or the pressure valve is sticking it will help. If the oil turns black right away you know the lower end is dirty and is getting cleaned.
Change your mufflers . Plugged exhaust on old barn bikes is common. Run without mufflers at all for a bit just to see what happens.
Raise the needles a notch, once again, just to see what happens.
Thanks again for your info, I shall try your recommendations
 

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Hi Peg, can you give me any details on how to check the valve timing with a degree wheel and what are the specs I am to look for? I will check the pistons to see if the old were burned as I don't have it here, my mate is working on it, shall check the seals also. I would like to count everything else out before splitting the bottom end. thanks again
Hi Drongo
You can make checks in 3 ways on valve timing using a timing disc,
a) valve opening and closing degrees.
b) valve lift at TDC.
C) Valve lobe centre timing.

I think you should start with opening and closing of the valves or valve lift at TDC depending on the information given by Triumph, we are only trying to verify the valve timing is in the right ball park, not blueprinting or tuning for power.

We have to make a big assumption here. The figures will only be close if the camshafts are standard original T140 cams, if a PO fitted aftermarket camshafts then the figures will be out, we might have to further check the lobe centres if that is the case.

I have just checked the manual and Triumph quote lift at TDC, so that is what we will use.

718308


You will need :
A degree disc, some wire to make a pointer, a dial gauge, a piston stop and an hour where you are totally undisturbed.

A) Firstly you need to remove the rocker covers and primary cover (drain primary oil first).
B) The degree disc needs to be attached to the alternator rotor so that it wont turn or move if knocked or jolted, but you can turn the disc independently of the rotor if you need to, a but of fine balancing of rotor bolt tension is needed.
C) Make and set up the pointer so it sits at the edge of the disc.
D) remove the spark plugs and turn the engine so you can set the valve clearances, reduce these to zero.
E) fit the piston stop in one spark plug hole. It is difficult to find TDC with the piston at the top because at this point there is a lot of crankshaft movement for very little piston movement, it is far more accurate to find TDC with the piston further down the bore.
wind in the piston stop then turn the engine all of the way forward until the piston hits the stop, turn and set the disc against the pointer at about 30 degrees. Now turn the engine all of the way backwards until the piston hits the stop. Check the pointer reading. If there is a difference in reading, adjust the disc against the pointer by half of the difference. Now try turning the engine all of the way forward and all of the way backward again, what you should achieve is the pointer on the disc reading the same number of degrees when the piston is against the stop, all of the way forwards and all of the way backwards. When you achieve this remove the piston stop and turn the engine so the pointer is at the zero degree TDC mark. This will be true Top Dead Centre.
F) Now turn the engine forward until you see an inlet valve start to open, turn the engine back until the valve just closes. (Do not use the alternator nut to turn the engine as you must not risk moving the timing disc).
Securely attach your dial gauge to the engine above the valve rocker/ tappet adjuster. zero the dial so that you can measure more than 0.2 inches, (5mm) turn the engine forward very slowly until you see the dial start to move as the valve opens, continue until the pointer is at 0 TDC. Take a measurement of how far the valve has opened and compare to the stock readings.
G) Repeat with the exhaust camshaft, remember the exhaust valve will be closing, so compensate with your direction of rotation.

Compare the readings with the standard figures, if they are close, then happy days, you can stop looking.
If they are different then either:
the camshaft is nonstandard .
or
the valve timing is not set right.

or
both, if we are very unlucky.

If the valve lift figures are out then we will need to remove the ignition and timing cover, then physically check the cam wheel alignment.
We can cross that bridge later, if we need to.

Regards
Peg.
 

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Hi Drongo,
I will add just a few other things not related to valve timing.

New carbs on standard jetting/Mikuni carb swap, I think this can be discounted for now as the cause of your woes, you appear to have done enough to eliminate this as the cause.
You have not said if you have standard air filters or exhaust, even so if they are not any little mixture quirks might produce a lack of sparkle, or a little it of pinging. but not the overheating you describe.

it might be worth checking the inlet manifold where it meets the head, if this is loose or leaking air. I usually place a few drops of locktite sealant around the edge and start the engine, the sealant will get sucked into any gaps and shuts off the leaks

You must have the very early 78 (USA only) T140E/V hybrid, I have one of these that was imported back to he UK about 20 years ago.

The sludge trap was designed to filter and hold the oil debris behind it and allow oil to flow through the centre, the sludge becomes very compacted by centrifugal force and is meant to stay there, until stripdown. Modern aftermarket oil filters combined with modern detergent cuts this sludge build up to a minimum. A full/blocked sludge trap can still be a problem. Here is an engine from a project bike I bought about 3 years ago, this is the crankshaft sludge trap from a 78 Tiger 750.
718319


Thinking about your dilemma of stripping down to check, you might be able to see if there is any oil flow through the crankshaft in case it is fully blocked like my one was. You will have to have the timing cover off to change the crankshaft oil seal (and maybe reset the valve timing). While there try getting an old fashioned pump oil can and see if you can pump oil through the crankshaft feed while slowly turning the engine. There will be some resistance as there is only a small gap between the crankshaft and big end shells. But it should not be completely blocked of very hard to pump.
718321


it won't tell you everything but you will be able to tell if it is completely or nearly blocked.

The crankshaft oil seal, need to be fitted the right way, it is not obvious which is the correct way. please be careful it is easy to get this wrong.
There are also various grades of seal out there, they all fit but some are totally unsuitable.
The originals were made by pioneer Western in the UK, but it is difficult to know if the produce them now. Several Copies are out there bearing the pioneer labelling. I am unable to find a UK dealer who advertises that he stands by his source of seals, so I import mine from the USA, who guarantees his made in USA seals.
I get the metal face seals as there seems to be less likelihood of inversion under pressure.

If you inspect the pressure relief valve, make sure that you do not overtighten the dome nut and distort the bore, causing the valve to stick. if you fit it back in the engine only tighten from the large outer nut, not the dome nut-even if it is difficult to do.

All for now
Regards
Peg.
 

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Like I said, if you jetted the new Amals to what the service manual for your bike says, that is probably wrong. You need to do a plug chop on some brand new spark plugs and see what the plugs are telling you.
 

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Discussion Starter #27
Like I said, if you jetted the new Amals to what the service manual for your bike says, that is probably wrong. You need to do a plug chop on some brand new spark plugs and see what the plugs are telling you.
Hi Mach, what jetting would you recommend as a starting point?
 

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Discussion Starter #28
Hi Drongo,
I will add just a few other things not related to valve timing.

New carbs on standard jetting/Mikuni carb swap, I think this can be discounted for now as the cause of your woes, you appear to have done enough to eliminate this as the cause.
You have not said if you have standard air filters or exhaust, even so if they are not any little mixture quirks might produce a lack of sparkle, or a little it of pinging. but not the overheating you describe.

it might be worth checking the inlet manifold where it meets the head, if this is loose or leaking air. I usually place a few drops of locktite sealant around the edge and start the engine, the sealant will get sucked into any gaps and shuts off the leaks

You must have the very early 78 (USA only) T140E/V hybrid, I have one of these that was imported back to he UK about 20 years ago.

The sludge trap was designed to filter and hold the oil debris behind it and allow oil to flow through the centre, the sludge becomes very compacted by centrifugal force and is meant to stay there, until stripdown. Modern aftermarket oil filters combined with modern detergent cuts this sludge build up to a minimum. A full/blocked sludge trap can still be a problem. Here is an engine from a project bike I bought about 3 years ago, this is the crankshaft sludge trap from a 78 Tiger 750.
View attachment 718319

Thinking about your dilemma of stripping down to check, you might be able to see if there is any oil flow through the crankshaft in case it is fully blocked like my one was. You will have to have the timing cover off to change the crankshaft oil seal (and maybe reset the valve timing). While there try getting an old fashioned pump oil can and see if you can pump oil through the crankshaft feed while slowly turning the engine. There will be some resistance as there is only a small gap between the crankshaft and big end shells. But it should not be completely blocked of very hard to pump.
View attachment 718321

it won't tell you everything but you will be able to tell if it is completely or nearly blocked.

The crankshaft oil seal, need to be fitted the right way, it is not obvious which is the correct way. please be careful it is easy to get this wrong.
There are also various grades of seal out there, they all fit but some are totally unsuitable.
The originals were made by pioneer Western in the UK, but it is difficult to know if the produce them now. Several Copies are out there bearing the pioneer labelling. I am unable to find a UK dealer who advertises that he stands by his source of seals, so I import mine from the USA, who guarantees his made in USA seals.
I get the metal face seals as there seems to be less likelihood of inversion under pressure.

If you inspect the pressure relief valve, make sure that you do not overtighten the dome nut and distort the bore, causing the valve to stick. if you fit it back in the engine only tighten from the large outer nut, not the dome nut-even if it is difficult to do.

All for now
Regards
Peg.
Thanks for that Peg, you sure are a wealth of information and I appreciate your help so much, I am beginning to feel confident we can get to the bottom of this, I spoke with may mate who has been doing the work on this and he assures me the pistons that were removed were OK slightly worn STD but in no way burned. I am now going to check the valve timing and the crank seal and pressure relief, by the way what oil do you recommend? I understood that a basic 20/50 without friction modifiers (cheap basic supermarket oil) is best for old motors?
 

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Hi Denny,
Important: After my engine was fully run in and the rings had seated.

If I had a brand new modern 2020 Hinkley Triumph,
I would buy the best quality correct grade fully synthetic motorcycle oil, the absolute best that I could afford.

But for an old classic Meriden bike,
I would buy the best quality correct grade fully synthetic motorcycle oil, the absolute best that I could afford.

If you can find it in the the NW Territories, Mobil 1 20/50 V twin has a great reputation, it is renowned for being heat resilient. It is a USA product designed for the Harley owners. Not available in UK and maybe not in AU.

For something more home grown, Penrite Oil has an excellent reputation amongst the Aus/NZ Triumph owners.
This oil appears to have everything I would be looking for, extra zinc/boron for flat tappet protection, fully synthetic pao ester, correct viscosity range. Jaso-MA spec (safe for use on a wet clutch), heat resilient.


Regards
Peg.

Fair Warning!
Oil is a very subjective topic, it’s a can of worms just waiting to be opened.
 

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Discussion Starter #31
Hi Denny,
Important: After my engine was fully run in and the rings had seated.

If I had a brand new modern 2020 Hinkley Triumph,
I would buy the best quality correct grade fully synthetic motorcycle oil, the absolute best that I could afford.

But for an old classic Meriden bike,
I would buy the best quality correct grade fully synthetic motorcycle oil, the absolute best that I could afford.

If you can find it in the the NW Territories, Mobil 1 20/50 V twin has a great reputation, it is renowned for being heat resilient. It is a USA product designed for the Harley owners. Not available in UK and maybe not in AU.

For something more home grown, Penrite Oil has an excellent reputation amongst the Aus/NZ Triumph owners.
This oil appears to have everything I would be looking for, extra zinc/boron for flat tappet protection, fully synthetic pao ester, correct viscosity range. Jaso-MA spec (safe for use on a wet clutch), heat resilient.


Regards
Peg.

Fair Warning!
Oil is a very subjective topic, it’s a can of worms just waiting to be opened.

Hi Peg, I can buy the Penrite MC4ST local for $80 4ltrs, and I will use this.
 

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Hi Denny,
Please note that these fully synthetic oils are so good that you might not be able to bed the rings in to your new bore, the oil just lubricates so well. The advice from most people is to use a standard oil for the running in period, then use the Fully Synthetic as soon as the engine is bedded in.
Regards
Peg.
 

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Discussion Starter #33
Hi Denny,
Please note that these fully synthetic oils are so good that you might not be able to bed the rings in to your new bore, the oil just lubricates so well. The advice from most people is to use a standard oil for the running in period, then use the Fully Synthetic as soon as the engine is bedded in.
Regards
Peg.
Thanks again Peg, I will follow your recommendations and run the new bores in with the basic oil before switching.
Denny
 

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Hi Denny, Was a balmy 70-75f today. So did a 99 mile lunch ride to Niles CA, USA. Took my infra thermometer. 1st time I've used it. My bike '73 Tiger with 8.6 pistons lowered compression from 170 to 150#. John has '69 Bonnie with 7.1 pistons.

Took first reading after 30 miles. Shocking how hot both bikes running. Ambient temp 70f, no breeze. Riding canyons, pulled over & measured within 20 seconds. 1/4" from spark plug recess on top fin 350f. At spark plug base 415f. Cyl fins near head same 350f. Couldn't get reliable reading on exhaust pipe near head. Doesn't like chrome. Set meter to chrome, no help. Read like 200f.

After 4 min idling no breeze 427f 1/4" from spark plug.

Johns bike read 5-15f lower in same conditions. Don't know why, Richer, timing, or the lower compression?? Both bikes running points.
My timing 36b (2deg retarded on purpose), John's timing 38b (to spec).

Most oddly both bikes run about 5f cooler on left side. Why?? Don't know.

Tested a few times later in ride with repeatable similar results.

I got home 3:40pm, now 75f ambient 45 miles non stop. My bike: 415f 1/4" from spark plug. 450f at base of plug, 415f on cyl fins. 270f at cyl base. Didn't test John's bike at end of day, he doesn't have thermometer.

Interesting 5f increase in ambient caused 65f increase 1/4" from plug & elsewhere.

Inboard of spark plug the head is very hot, similar to spark plug. Harder to get repeatable results, but always was much hotter than top fin.

Spit boils about 221f. It dances on hot surface about 350f+. Spit danced freely on the top head fins. Danced on upper cyl fins. Just steamed on cyl base flange.

Outer covers on motor so hot, to fingers or meter, but hard to get accurate reading on polished surface. Still couldn't touch any part of motor for more than a moment with finger. Top of trans was about 200f in center.

Who knows how accurate my meter is. No way to test it really. But spit dancing is meaningful.

I'll let you convert deg F to C.
Don
 

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Discussion Starter #35
Hi Denny, Was a balmy 70-75f today. So did a 99 mile lunch ride to Niles CA, USA. Took my infra thermometer. 1st time I've used it. My bike '73 Tiger with 8.6 pistons lowered compression from 170 to 150#. John has '69 Bonnie with 7.1 pistons.

Took first reading after 30 miles. Shocking how hot both bikes running. Ambient temp 70f, no breeze. Riding canyons, pulled over & measured within 20 seconds. 1/4" from spark plug recess on top fin 350f. At spark plug base 415f. Cyl fins near head same 350f. Couldn't get reliable reading on exhaust pipe near head. Doesn't like chrome. Set meter to chrome, no help. Read like 200f.

After 4 min idling no breeze 427f 1/4" from spark plug.

Johns bike read 5-15f lower in same conditions. Don't know why, Richer, timing, or the lower compression?? Both bikes running points.
My timing 36b (2deg retarded on purpose), John's timing 38b (to spec).

Most oddly both bikes run about 5f cooler on left side. Why?? Don't know.

Tested a few times later in ride with repeatable similar results.

I got home 3:40pm, now 75f ambient 45 miles non stop. My bike: 415f 1/4" from spark plug. 450f at base of plug, 415f on cyl fins. 270f at cyl base. Didn't test John's bike at end of day, he doesn't have thermometer.

Interesting 5f increase in ambient caused 65f increase 1/4" from plug & elsewhere.

Inboard of spark plug the head is very hot, similar to spark plug. Harder to get repeatable results, but always was much hotter than top fin.

Spit boils about 221f. It dances on hot surface about 350f+. Spit danced freely on the top head fins. Danced on upper cyl fins. Just steamed on cyl base flange.

Outer covers on motor so hot, to fingers or meter, but hard to get accurate reading on polished surface. Still couldn't touch any part of motor for more than a moment with finger. Top of trans was about 200f in center.

Who knows how accurate my meter is. No way to test it really. But spit dancing is meaningful.

I'll let you convert deg F to C.
Don
Thanks Don, much appreciate this for a comparison
Denny
 

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I have just the opposite of too hot. I can belt mine along for 50 miles and the engine is still cool to the touch. The cases, you can keep your hands on and luke warm. Head and barrels are always very hot as i would expect. The only time it will get moderately hot is with a passenger and a combined weight of around 400 lbs. Sea level riding and 1000 ft above sea level at times.
 

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Discussion Starter #38
I have just the opposite of too hot. I can belt mine along for 50 miles and the engine is still cool to the touch. The cases, you can keep your hands on and luke warm. Head and barrels are always very hot as i would expect. The only time it will get moderately hot is with a passenger and a combined weight of around 400 lbs. Sea level riding and 1000 ft above sea level at times.
Are you running full synthetic oil?
 

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Mineral oil 20/50 most of the time. I do use a V-twin oil that might be a semi synthetic. Long term ownership on this bike. When it had 6550 dispacement and rider and passenger, it di get very hot on long fast rides. To the point that it seized a piston. About 15 years ago, i replaced the cylinders with a 750 kit and lower compression and it never gets too hot. I did have an oil cooler but now, i have removed it.
Oil in the down tube is 53 Centigrade after a 30 mile fast ride.
Peg has mentioned the engine oil might not be going through the crank in quantity. That might be so. My crank seal in the timing side is a top quality one from Tri-supply. I have inverted a seal once when using higher RPM with cold oil. I keep engine speed low for the first 5 miles now.
Looking at the temps of Dons bike, maybe the heat is just the friction of a new bore and the heat will drop as it beds in. Dons temps seem high yet it runs fine.
 

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Just out of interest, this is the sludge trap on my crank at 40,000 miles. Note that the crank has a split which is why i took it out. All the oil intended for the shells was just squirting out the crack so no oil pressure at all. The bike still ran and i got home 8 miles at 2000 rpm. Lucky the crank held together as it had begun twisting. It snapped as i let off the throttle at 80 mph.
 

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