*Parts Compatibility - TBS 1998

atomsplitter said:
Could be bad news. Pull the idle mix screws and see if the tips are undamaged. If either tip is broken off your carb body is ruined and you'll need a new carb body. Happened to me on a used Yamaha XS1100 years ago, I had to buy a full 4 carb set. Luckily you have some spares. As to the battery, put it on a charger and see if it can get to 13.2 volts off the charger. If so, good, if not, new battery time.

BTW here's that old Yamaha:
View attachment 57660
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That’s a beautiful bike. Finally got back around to my bike.

I rebuilt and cleaned the carbs annd anttached the tank. again same issue as before. Wants to start w starter fluid and will start running but once I let go of the the starter it dies out. Don’t wanna drain my battery but also when I try twisting the throttle it dies out immediately.

It could be the floats not be at the right level. But I just checked old idle needles on one of them is bent. I don’t think i need to adjust the idle( the rpm meter when it does start goes to 1000rpm) needle or maybe I do. Possibly it’s got old gas and needs to get burnt out or I’m SOFL and need a new carb body. If that’s the case we’re there after market carb bodies or I gotta scour eBay?
 
What does this do ? IMG_3438.jpeg
 
Looks like the idle set screw to me. It raises and lowers the carb butterfly stop for all three carbs. After the carbs are synced you set idle speed with it (if that's what it is).
 
Turn that screw clockwise a couple of turns and see if you can get it to idle...
 
Maybe we already covered this, but, I see you have pod filters. What jets are in those carbs?
 
Unless you have a wildly open exhaust the 108's should be fine. The real question is did you get it to start and run?
 
atomsplitter said:
Unless you have a wildly open exhaust the 108's should be fine. The real question is did you get it to start and run?
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I drained the battery trying to get it to run last time, So No. had to run outta town so I left it on a charger. i got my 1989 Toyota Corolla running and idling. That corolla 4a-f engine is carbureted. One project down! Gotta have wheels in south Florida. Now I can focus on the triumph. I’ll be adjusting all the jets and floats till I get it just right. So close and I refuse to give up!
 
Assuming the carbs are very clean and no air leaks at the intake manifold, the bike should at least cough with the choke on. The main jets (108's) don't come into play until about 4000 RPM so it's the idle and intermediate fuel circuits that are the question. If you're getting gas into the float bowls the bike should fire. Does the bike have a vacuum operated petcock? If so you want to use the 'prime' position on the fuel selector.
 
Atomsplitter is correct; the jetting shouldn't affect starting. Running is a different story. I had Emgo pods, and later K&N pods, and I ended up with 45 pilots and 150 mains. 42 pilots and one shim under the needle was actually a little better, but it killed the mileage at cruise. Bottom line: it really needed a different needle. With a 108 main it will run out of gas at full throttle. Chances are you won't be able to hit the rev limiter in the higher gears. With the correct mains it should pull hard right up to the rev limiter, and the limit should feel almost like hitting the kill switch.
 
Biiim said:
………………….Still wrestling a stripped socket hex screw rn
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Try a Torx bit in it. The hex socket screws for the cam belt tensioners on my Ducati are a loose fit and don’t inspire confidence so I use a Torx bit which is a snugger fit.
 
atomsplitter said:
Assuming the carbs are very clean and no air leaks at the intake manifold, the bike should at least cough with the choke on. The main jets (108's) don't come into play until about 4000 RPM so it's the idle and intermediate fuel circuits that are the question. If you're getting gas into the float bowls the bike should fire. Does the bike have a vacuum operated petcock? If so you want to use the 'prime' position on the fuel selector.
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I’m getting gas to float bowls for sure. I think it’s the idle? Maybe I messed up an idle screw tightening too tight. Would that throw the whole thing off?
 
atomsplitter said:
Assuming the carbs are very clean and no air leaks at the intake manifold, the bike should at least cough with the choke on. The main jets (108's) don't come into play until about 4000 RPM so it's the idle and intermediate fuel circuits that are the question. If you're getting gas into the float bowls the bike should fire. Does the bike have a vacuum operated petcock? If so you want to use the 'prime' position on the fuel selector.
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The gas tank has a petcock
 
Biiim said:
I’m getting gas to float bowls for sure. I think it’s the idle? Maybe I messed up an idle screw tightening too tight. Would that throw the whole thing off?
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If it's the normal Triumph setup the idle mixture screws feed air or fuel to the idle circuit. From the looks of the needles they are fuel valves and if the needle tip is broken off in the hole, no fuel will flow in the idle circuit. The initial setting should be about 2.5 turns out from LIGHTLY seated (basically at the point the screw hits bottom and stops with two fingers on the screwdriver). If you jammed an idle mixture screw in then you need to remove it and inspect the needle tip is intact (see post #125). If you broke one (or more) off in the pilot hole that carb is trash and you need a new carb body. Assuming your needles are intact you should invest in a Colortune (link provided) to dial in the correct idle mix. There are Youtube videos on how to use the Colortune (I have one, they make life a lot easier with carbs).

 
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At this point I would remove the carburetor assembly from the bike. It’ll be a lot easier to inspect and remove parts.
 
atomsplitter said:
If it's the normal Triumph setup the idle mixture screws feed air or fuel to the idle circuit. From the looks of the needles they are fuel valves and if the needle tip is broken off in the hole, no fuel will flow in the idle circuit. The initial setting should be about 2.5 turns out from LIGHTLY seated (basically at the point the screw hits bottom and stops with two fingers on the screwdriver). If you jammed an idle mixture screw in then you need to remove it and inspect the needle tip is intact (see post #125). If you broke one (or more) off in the pilot hole that carb is trash and you need a new carb body. Assuming your needles are intact you should invest in a Colortune (link provided) to dial in the correct idle mix. There are Youtube videos on how to use the Colortune (I have one, they make life a lot easier with carbs).

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I inspected the original idle screws and one was bent.
 
You'll need a new idle screw so get the full set and replace all of them. Once you have the new screws make sure the tips on the old ones are the same length as the new, no 'short' tips because that would mean a blocked port in the carb body. If all is good then use some spray carb cleaner in the holes to clear any debris before putting the new needles in. ONLY finger tight LIGHTLY bottom the needles, then back out 2.5 turns. That's your initial starting point.
 
You can get aftermarket idle screws that have a thumbscrew rather than a hidden screw driver slot. If you're buying anything, I'd get three of those.

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