Hi Frank & Kevin, thanks for all of your videos. I have loved every one of them. Regarding the Triumph T20 over here in the U.K. we call them The Tiger Cub. I was never a fan of the look this model until I saw this one in Kevin’s shop, the colours are perfect and I now love the look of The Tiger Cub. I hope you get to a satisfactory end to this rebuild. Thanks again boys.
Neat guy! Does great work. There are a few differences between our project and his though. We are both using the same Boyer Power Box to convert the AC alternator output to the DC needed for the ignition. Our bike was originally a five-wire ET alternator AC ignition system which we converted to a two-wire DC ignition system using the same Boyer Power Box. So our bikes are the same up the choice of ignition systems. I "expect" that he is using the original mechanical 12 degree advance unit points ignition system. We took out the ET's 5 degree advance unit and mechanical points and installed a Pazon electronic ignition system. We are both using the 7mm BTDC timing which "should" convert to 28 degrees BTDC. But the specs for the T20M call for 32 degrees BTDC so there is a bit of confusion there. However, although the bike is vexing us by being hard to start, it runs GREAT once it gets going, telling us that the ignition timing is (probably, possibly) OK. BTW: When the bike is in it's "I don't wanna start mood" hooking a battery to the ignition system does NOT help. So now we are reduced to spending more of the client's money on a new carb. We've probably put 30 hours of un-charged labor hours into this project and are getting desperate. Keep watching, the carb should be here in a week or so and we will see if it helps. BTW: Installing 12 degree mechanical points is not out of the question if all else fails. And the fun just never stops.
I follow you guys and I also follow a man named Paul Henshaw classic motorcycle channel. He is working on pretty much the same bike right now. He goes into some interesting things with timing. You might like it and find a tip that would make yours start better. Just a thought.
His latest one kick start cub instalment. Highlight being Paul's eureka moment regarding the powerbox with a capacitor incorporated for improved battery less starting. Although I believe from an earlier video this has been fitted to this pretty T20M. th-cam.com/video/e1eV0feMVwo/w-d-xo.htmlsi=OZ4IIUIR4fF8cWTr
I have a Triumph Service Bulletin from 1967 that I just found today, that says the ignition for a Triumph T20M should be set to 32 degrees fully advanced. This is when running stock 7:1 compression pistons. It also say that if the bike develops a hard starting problem, and the spark at kickstart speeds is weak, remove the primary cover and check that at top dead center, the keyway in the drive side shaft located at 3 o'clock should always be used to drive the rotor. For whatever that is worth!
Thanks. The rotor on this bike is single-keyed to the crankshaft, so the positioning is fixed. But it is fixed at 3 o'clock, so that's good news. And now that we have the standard 2-wire alternator and Boyer Power Box we have spark that lights up the room. But, the admonition that the spark will be weaker at kickover (without a battery) still holds true.
The slide problem is very common. push the slide forward with your finger when the engine is running slow. You'll be surprised at the results. Great channel. 👍.
One more point of note from that service bulletin I mentioned in the previous comment. It says the following about valve clearances: "After engine number 5004 a standard camshaft with ramp cams was fitted to the T20M model and the valve clearance for any machine after that number should be adjusted to 0.010" for best performance." Hope these 2 notes help you guys out.
Many Cubs came with a funny little carb called a Zenith. Not eveybody's cup of tea and it certainly had its limitations, but it certainly did the job on the Cubs.
An old way to mitigate oil leak on a shaft was to use a leather or felt piece of material internally. Internal pressure from the piston will push oil out of loose gap areas.
Neat guy! Does great work. There are a few differences between our project and his though. We are both using the same Boyer Power Box to convert the AC alternator output to the DC needed for the ignition. Our bike was originally a five-wire ET alternator AC ignition system which we converted to a two-wire DC ignition system using the same Boyer Power Box. So our bikes are the same up the choice of ignition systems. I "expect" that he is using the original mechanical 12 degree advance unit points ignition system. We took out the ET's 5 degree advance unit and mechanical points and installed a Pazon electronic ignition system. We are both using the 7mm BTDC timing which "should" convert to 28 degrees BTDC. But the specs for the T20M call for 32 degrees BTDC so there is a bit of confusion there. However, although the bike is vexing us by being hard to start, it runs GREAT once it gets going, telling us that the ignition timing is (probably, possibly) OK. BTW: When the bike is in it's "I don't wanna start mood" hooking a battery to the ignition system does NOT help. So now we are reduced to spending more of the client's money on a new carb. We've probably put 30 hours of un-charged labor hours into this project and are getting desperate. Keep watching, the carb should be here in a week or so and we will see if it helps. BTW: Installing 12 degree mechanical points is not out of the question if all else fails. And the fun just never stops.
Neat guy! Does great work. There are a few differences between our project and his though. We are both using the same Boyer Power Box to convert the AC alternator output to the DC needed for the ignition. Our bike was originally a five-wire ET alternator AC ignition system which we converted to a two-wire DC ignition system using the same Boyer Power Box. So our bikes are the same up the choice of ignition systems. I "expect" that he is using the original mechanical 12 degree advance unit points ignition system. We took out the ET's 5 degree advance unit and mechanical points and installed a Pazon electronic ignition system. We are both using the 7mm BTDC timing which "should" convert to 28 degrees BTDC. But the specs for the T20M call for 32 degrees BTDC so there is a bit of confusion there. However, although the bike is vexing us by being hard to start, it runs GREAT once it gets going, telling us that the ignition timing is (probably, possibly) OK. BTW: When the bike is in it's "I don't wanna start mood" hooking a battery to the ignition system does NOT help. So now we are reduced to spending more of the client's money on a new carb. We've probably put 30 hours of un-charged labor hours into this project and are getting desperate. Keep watching, the carb should be here in a week or so and we will see if it helps. BTW: Installing 12 degree mechanical points is not out of the question if all else fails. And the fun just never stops.
What a frustrating job this one is turning out to be. Do you believe a new carb would allow it to fire up earlier/ more easily? Or is there some other reason it just doesn’t want to start from cold? Unless the next vid shows that issue has been overcome.
Looks like it must be right then. That’s a very small (and rich) cut away, I have never come across anything smaller than 3 in 55 years of playing with British motorcycles! I did have a Cub for a short while but it had a zenith carb. They always struck me as a delicate little engine; probably the reason why I didn’t keep it long!
reason for erratic idling is possibly the mounting nuts are way too tight, thereby distorting the mounting flange, try a new throttle slide before buying a new carb. also, just depress the tickler once for 2 seconds max. when warm should not need flooding at all.
Hi Frank & Kevin, thanks for all of your videos. I have loved every one of them. Regarding the Triumph T20 over here in the U.K. we call them The Tiger Cub. I was never a fan of the look this model until I saw this one in Kevin’s shop, the colours are perfect and I now love the look of The Tiger Cub. I hope you get to a satisfactory end to this rebuild. Thanks again boys.
Paul Henshaw is very knowledgeable on British Iron. I enjoy yours and his channels for being honest about the difficulties.
Neat guy! Does great work. There are a few differences between our project and his though. We are both using the same Boyer Power Box to convert the AC alternator output to the DC needed for the ignition. Our bike was originally a five-wire ET alternator AC ignition system which we converted to a two-wire DC ignition system using the same Boyer Power Box. So our bikes are the same up the choice of ignition systems. I "expect" that he is using the original mechanical 12 degree advance unit points ignition system. We took out the ET's 5 degree advance unit and mechanical points and installed a Pazon electronic ignition system. We are both using the 7mm BTDC timing which "should" convert to 28 degrees BTDC. But the specs for the T20M call for 32 degrees BTDC so there is a bit of confusion there. However, although the bike is vexing us by being hard to start, it runs GREAT once it gets going, telling us that the ignition timing is (probably, possibly) OK. BTW: When the bike is in it's "I don't wanna start mood" hooking a battery to the ignition system does NOT help. So now we are reduced to spending more of the client's money on a new carb. We've probably put 30 hours of un-charged labor hours into this project and are getting desperate. Keep watching, the carb should be here in a week or so and we will see if it helps. BTW: Installing 12 degree mechanical points is not out of the question if all else fails. And the fun just never stops.
@@fjdelmonte thank you for that explanation..you answered a lot of people's questions I'm sure.(mine anyway)
I follow you guys and I also follow a man named Paul Henshaw classic motorcycle channel. He is working on pretty much the same bike right now. He goes into some interesting things with timing. You might like it and find a tip that would make yours start better. Just a thought.
I agree
He really knows his tiger cubs
He sets his at 7mm btdc at full advance
I believe he did state, this dimension may change, dependant on the tune of the engine.
His latest one kick start cub instalment. Highlight being Paul's eureka moment regarding the powerbox with a capacitor incorporated for improved battery less starting. Although I believe from an earlier video this has been fitted to this pretty T20M.
th-cam.com/video/e1eV0feMVwo/w-d-xo.htmlsi=OZ4IIUIR4fF8cWTr
I have a Triumph Service Bulletin from 1967 that I just found today, that says the ignition for a Triumph T20M should be set to 32 degrees fully advanced. This is when running stock 7:1 compression pistons. It also say that if the bike develops a hard starting problem, and the spark at kickstart speeds is weak, remove the primary cover and check that at top dead center, the keyway in the drive side shaft located at 3 o'clock should always be used to drive the rotor. For whatever that is worth!
Thanks. The rotor on this bike is single-keyed to the crankshaft, so the positioning is fixed. But it is fixed at 3 o'clock, so that's good news. And now that we have the standard 2-wire alternator and Boyer Power Box we have spark that lights up the room. But, the admonition that the spark will be weaker at kickover (without a battery) still holds true.
The slide problem is very common. push the slide forward with your finger when the engine is running slow. You'll be surprised at the results. Great channel. 👍.
Oooo! Neat idea! Thanks.
One more point of note from that service bulletin I mentioned in the previous comment. It says the following about valve clearances: "After engine number 5004 a standard camshaft with ramp cams was fitted to the T20M model and the valve clearance for any machine after that number should be adjusted to 0.010" for best performance." Hope these 2 notes help you guys out.
Wow! Would you please scan that SB and email it to me? I know we have the valves at .002 and .004. Interesting! Thanks. info@AzBritBikes.com.
Found it. Thanks anyway!
Many Cubs came with a funny little carb called a Zenith. Not eveybody's cup of tea and it certainly had its limitations, but it certainly did the job on the Cubs.
An old way to mitigate oil leak on a shaft was to use a leather or felt piece of material internally. Internal pressure from the piston will push oil out of loose gap areas.
Paul from Wales give you two a mention. He gives some info. about his carb settings.
Link?
th-cam.com/video/e1eV0feMVwo/w-d-xo.htmlsi=J12_GQRNtum1Vyba
Neat guy! Does great work. There are a few differences between our project and his though. We are both using the same Boyer Power Box to convert the AC alternator output to the DC needed for the ignition. Our bike was originally a five-wire ET alternator AC ignition system which we converted to a two-wire DC ignition system using the same Boyer Power Box. So our bikes are the same up the choice of ignition systems. I "expect" that he is using the original mechanical 12 degree advance unit points ignition system. We took out the ET's 5 degree advance unit and mechanical points and installed a Pazon electronic ignition system. We are both using the 7mm BTDC timing which "should" convert to 28 degrees BTDC. But the specs for the T20M call for 32 degrees BTDC so there is a bit of confusion there. However, although the bike is vexing us by being hard to start, it runs GREAT once it gets going, telling us that the ignition timing is (probably, possibly) OK. BTW: When the bike is in it's "I don't wanna start mood" hooking a battery to the ignition system does NOT help. So now we are reduced to spending more of the client's money on a new carb. We've probably put 30 hours of un-charged labor hours into this project and are getting desperate. Keep watching, the carb should be here in a week or so and we will see if it helps. BTW: Installing 12 degree mechanical points is not out of the question if all else fails. And the fun just never stops.
Perhaps a small battery or a capacitor would help the lighting issue at idle. A small lithium ion battery may just do the trick
Agreed, fluctuating or low voltage is going to play havoc with that electronic box.
Neat guy! Does great work. There are a few differences between our project and his though. We are both using the same Boyer Power Box to convert the AC alternator output to the DC needed for the ignition. Our bike was originally a five-wire ET alternator AC ignition system which we converted to a two-wire DC ignition system using the same Boyer Power Box. So our bikes are the same up the choice of ignition systems. I "expect" that he is using the original mechanical 12 degree advance unit points ignition system. We took out the ET's 5 degree advance unit and mechanical points and installed a Pazon electronic ignition system. We are both using the 7mm BTDC timing which "should" convert to 28 degrees BTDC. But the specs for the T20M call for 32 degrees BTDC so there is a bit of confusion there. However, although the bike is vexing us by being hard to start, it runs GREAT once it gets going, telling us that the ignition timing is (probably, possibly) OK. BTW: When the bike is in it's "I don't wanna start mood" hooking a battery to the ignition system does NOT help. So now we are reduced to spending more of the client's money on a new carb. We've probably put 30 hours of un-charged labor hours into this project and are getting desperate. Keep watching, the carb should be here in a week or so and we will see if it helps. BTW: Installing 12 degree mechanical points is not out of the question if all else fails. And the fun just never stops.
What a frustrating job this one is turning out to be. Do you believe a new carb would allow it to fire up earlier/ more easily? Or is there some other reason it just doesn’t want to start from cold? Unless the next vid shows that issue has been overcome.
Early Boyer's will not start/run if insufficent voltage is available e.g if battery is low and h/lights turned on,motor cuts out.
Factory carb specs for 1965 T20SM as follows........MJ 140, NJ .105, Needle type C, PJ 15, Slide 376 / 2 1/2.
Are you sure about the 2 1/2 cut away? The Amal data base gives a 3 1/2 for the Amal 376/314 fitted to this Cub.
@@lindsaysampford3190 Specs are straight off my factory microfishe file;
@@lindsaysampford3190 My replacement parts catalogue No 1 specifically lists a 2.5 cutaway for 1965 T20SM.
Looks like it must be right then.
That’s a very small (and rich) cut away, I have never come across anything smaller than 3 in 55 years of playing with British motorcycles!
I did have a Cub for a short while but it had a zenith carb. They always struck me as a delicate little engine; probably the reason why I didn’t keep it long!
reason for erratic idling is possibly the mounting nuts are way too tight, thereby distorting the mounting flange, try a new throttle slide before buying a new carb. also, just depress the tickler once for 2 seconds max. when warm should not need flooding at all.
no need to pump primer just hold down to flood carb the higher compression later the timing HAPPY WRENCHING