1971 T100C Refresh

[JerryP]

The new Street Scrambler is a nice looking bike! I’ve thought one of the modern Triumphs might be a good choice with he modern accessories, etc. I did a rebuild of a 1967 Bonneville into a sort of scrambler/desert sled bike, and I have another thread on this forum that chronicles my build. I’m still running the engine in and hoping that I can cure a minor oil leak since the engine was totally rebuilt. I found some aluminum fenders for this bike that look pretty good. I’m finding this T100C I have is a bit more comfortable to ride.

I think I would of liked to get a rebuilt T100C as they are so light. Changing back to right foot shift might be a challenge. I wonder if you ever got to drive a Rickman bike with the giant sprocket. A friend of mine lent me his for an afternoon ride. Pulls the wheel up at will and feels even lighter than the T100C. Listen Chapel was a flat track rider (#52) and was badly injured in 1970 and passed away not long after in Gainesville, FL. The Street Scrambler is a heavy bike but seat height is low enough for this old guy. Tops out at 90 mph but is good off the line and in city traffic. I think I did read your story about the '67...Interesting as I also owned a TR-6 (1971) and that was very much like the Street Twin.

 

[Sundance]

I think I would of liked to get a rebuilt T100C as they are so light. Changing back to right foot shift might be a challenge. I wonder if you ever got to drive a Rickman bike with the giant sprocket. A friend of mine lent me his for an afternoon ride. Pulls the wheel up at will and feels even lighter than the T100C. Listen Chapel was a flat track rider (#52) and was badly injured in 1970 and passed away not long after in Gainesville, FL. The Street Scrambler is a heavy bike but seat height is low enough for this old guy. Tops out at 90 mph but is good off the line and in city traffic. I think I did read your story about the '67...Interesting as I also owned a TR-6 (1971) and that was very much like the Street Twin.

Yes, this T100C seems very light for some reason - perhaps because it is! On the Rickman, I think that’s the bike I’d like. I’ve been looking for one in the US, even a rolling chassis , one that I might be able to build with either a 500 or 650 Triumph engine. Seems they are far and few., but I hear they are quite light and handle well. I might consider parting with my T100C if I can find a Rickman project.

 

[Sundance]

Fibre Washers - Rather than getting fibre washers piecemeal (say from a vintage bike retailer) for my bikes when changing oil, etc, I am wondering if any member has had luck with finding a place to get an assortment of good quality fibre washers of various sizes useful on Triumphs? Thanks for any advice on this.

 

[JerryP]

If you're in Central FL, ACME Industrial Surplus, 1461 Kastner PL, Sanford FL 407-328-1280. Huge assortment of aluminum & stainless nuts bolts, diamond plate, tubes, rods, tools, at salvage prices. Look for the 30' silver spaceman statue. Just off I-4 in Sanford.

 

[Sundance]

If you're in Central FL, ACME Industrial Surplus, 1461 Kastner PL, Sanford FL 407-328-1280. Huge assortment of aluminum & stainless nuts bolts, diamond plate, tubes, rods, tools, at salvage prices. Look for the 30' silver spaceman statue. Just off I-4 in Sanford.

Thanks for the reply JerryP. Sounds like a great place. I am up in Northern Virginia however so will look for something up in this area.

 

[JerryP]

Sundance, Try looking up "ProBolt" Just went looking for their catalog, couldn't locate it, but they have an unbelievable amount of anodized bolts, nuts, washers. Located in England but the FL rep mails stuff out daily. Their metric flat bolt/thread gauge is a must for the toolbox. (under $10) Their catalogue is free too and they will source out what you need. www.probolt-usa.com. Another source near you is Wheeling Cycle Supply Wheeling, WV. Forest Green 1-888-274-0886 (www.wheelingcyclesupply.com)

 

[Sundance]

Sundance, Try looking up "ProBolt" Just went looking for their catalog, couldn't locate it, but they have an unbelievable amount of anodized bolts, nuts, washers. Located in England but the FL rep mails stuff out daily. Their metric flat bolt/thread gauge is a must for the toolbox. (under $10) Their catalogue is free too and they will source out what you need. www.probolt-usa.com. Another source near you is Wheeling Cycle Supply Wheeling, WV. Forest Green 1-888-274-0886 (www.wheelingcyclesupply.com)

Thanks again JerryP. I took a look at these and they look like great sources!

 

[Sundance]

I was finally taking my T100C out for a longer run, about 45 miles. I was returning on a parkway, driving at about 55 mph for 15 miles before turning off. When I turned off I slowed down then attempted to speed up and ship into 4th gear. The bike lost power and stopped running, so I shifted to 3rd and it started again, but would not keep running unless I had high revs. This happened several times on the few miles back home. It seemed like it might not be getting fuel, but then when I kept the revs up it was ok. I eventually turned it off and it restarted with no problem. Any comments are appreciated!

 

[Sundance]

I am rebuilding the carburetor on this bike as I believe that was the problem I was having with intermittent fueling. It turns out the float was worn through so was likely sticking. I've got the carb apart and waiting for parts.

I decided to redo the fuel lines also and when examining found that the petcocks were leaking, that is when fully closed there was still some fuel coming through.

I was hoping I could rebuild the petcocks also, as there seems to be a rubber washer inside the petcock that could be replaced

. I haven't found anything on-line about rebuilding these so I am wondering if any of you have rebuilt your petcocks previously, and if so where did you find the new internal pieces?

Thanks for your help!

 

[Sundance]

So I never found a rebuild kit for my peacocks. I went to ace hardware and found some o rings the same size as in these old petcocks - as the old ones were hard as a rock. It was relatively easy to disassemble the petcocks, clean them with 000 steel wool, replace the o ring and put back together. Now to test them for leaks.

 

[Sundance]

I was finally taking my T100C out for a longer run, about 45 miles. I was returning on a parkway, driving at about 55 mph for 15 miles before turning off. When I turned off I slowed down then attempted to speed up and ship into 4th gear. The bike lost power and stopped running, so I shifted to 3rd and it started again, but would not keep running unless I had high revs. This happened several times on the few miles back home. It seemed like it might not be getting fuel, but then when I kept the revs up it was ok. I eventually turned it off and it restarted with no problem. Any comments are appreciated!

So, I rebuilt the carb and installed it tonight, hoping it would solve the problem of cutting out. It started right up after 2 kicks and smoked a bit, probably due to not having been run for awhile. The the problem started again. It would start up, sometimes run smooth, sometimes rough. If I got it running and held the throttle at one position, the revs would not stay stable but run higher and lower. Then it would start to cut out and I could keep it running if I manipulated the throttle up and down, but eventually it stops. It seems like it is getting starved of fuel, but I am not sure because it would start up and run a bit. Then there were times if I gave it too much throttle it would die. So I am not sure what to check next and welcome any thoughts. Ran it with the gas cap in and off and no difference. Thanks for any advice!

 

[suzook12]

So, I rebuilt the carb and installed it tonight, hoping it would solve the problem of cutting out. It started right up after 2 kicks and smoked a bit, probably due to not having been run for awhile. The the problem started again. It would start up, sometimes run smooth, sometimes rough. If I got it running and held the throttle at one position, the revs would not stay stable but run higher and lower. Then it would start to cut out and I could keep it running if I manipulated the throttle up and down, but eventually it stops. It seems like it is getting starved of fuel, but I am not sure because it would start up and run a bit. Then there were times if I gave it too much throttle it would die. So I am not sure what to check next and welcome any thoughts. Ran it with the gas cap in and off and no difference. Thanks for any advice!

Sounds like carb could be blocked in internal drillings.... Just replaced mine for that very reason. 20 minutes and running...

 

[Sundance]

Electrical troubleshooting! I'm still having trouble troubleshooting my 1971, Triumph, T100C electrical issue. I checked the wiring of the Boyer-Brandsen MK IV and it looks to be properly appointed. As far as I can see it is getting juice. I made a YouTube video in case any members can take a look and help me a bit more with the diagnosis. Thanks if you'll take a look here:
View: https://youtu.be/G0twPesancU

 

[Sundance]

Electrical troubleshooting! I'm still having trouble troubleshooting my 1971, Triumph, T100C electrical issue. I checked the wiring of the Boyer-Brandsen MK IV and it looks to be properly appointed. As far as I can see it is getting juice. I made a YouTube video in case any members can take a look and help me a bit more with the diagnosis. Thanks if you'll take a look here:
View: https://youtu.be/G0twPesancU

Now I am wondering if this is a different electrical problem or a carb problem. See the attached video of the plugs sparking when kicking the engine over. They seem consistent and uniform. Also, the plugs are wet when removing after running, so could this be a fueling issue and how would I troubleshoot this?

https://youtube.com/shorts/C3Ui9Z6fVgQ?

 

[Sundance]

I'm still trying to figure this out. So the bike starts easily, but still runs rough, like it is missing intermittently. When running I removed one the right spark plug wire and it kept running, but less firing. After connecting the right plug, I then removed the left, and it kept running, but just barely. So it would seem the left side is not running as smoothly as the right side. So could this be a left side coil or wiring issue that for some reason is not letting the left side spark as strongly as the right side? Thanks for advice!

 

[sikatri]

I'm still trying to figure this out. So the bike starts easily, but still runs rough, like it is missing intermittently. When running I removed one the right spark plug wire and it kept running, but less firing. After connecting the right plug, I then removed the left, and it kept running, but just barely. So it would seem the left side is not running as smoothly as the right side. So could this be a left side coil or wiring issue that for some reason is not letting the left side spark as strongly as the right side? Thanks for advice!

Have you tried switching wires and coils? Is it two coils or a single with two plugs?

 

[Sundance]

Have you tried switching wires and coils? Is it two coils or a single with two plugs?

great idea, I have 2 coils, 6 volt, so that is a great idea - thanks!!

 

[Sundance]

OK, so I tried switching coils. I ran the bike with the spark plugs wires switched to the other plugs - ran the same rough. Then I started and ran the bike on the right cylinder only, once with the left coil and once with the right coil. I did the same with the left cylinder. All four times it seemed to run the same, no missing just running on once cylinder. So I am wondering what this tells me . . . it seems that both coils are working OK? Also both spark plug wires seem to work ok, even on just one cylinder. So when I hook the plugs up normally, it is still running rough, so more than one cylinder is firing, just not evenly. Any advice?

 

[solomon]

Swap carbs over. See if problem changes to other cylinder.
Edit
Sorry. You only have one carb.
Check for gasket leak at carb/cylinder?

 

[Sundance]

Swap carbs over. See if problem changes to other cylinder.

OK so this is a 1971 T100C 500 Trophy, so single carb. I had this problem and thought it was the carb so rebuilt it, but am having the same problem since I put the rebuilt carb back on.