TFT Posted January 13, 2022 Posted January 13, 2022 (edited) The carbs on my 1997 XX are gummed up, they have never been rebuilt. I had the same issue with my other 97 XX that I sold. I found this Carburetor rebuild kit and am considering ordering it. Any experience with this or any recommendations? https://www.motorcycleid.com/1997-honda-cbr1100xx-super-blackbird-carburetor-rebuild-kits/ Edited January 14, 2022 by TFT Quote
superhawk996 Posted January 13, 2022 Posted January 13, 2022 You probably just need to clean the jets. At most you'd need new bowl gaskets, but they often re-seal just fine. Quote
TFT Posted January 14, 2022 Author Posted January 14, 2022 I tried starting it and it won’t stay running, it starts, idles for a few seconds and then acts like it’s running out of fuel and dies. any thoughts? Quote
DBLXX Posted January 14, 2022 Posted January 14, 2022 1 hour ago, TFT said: I tried starting it and it won’t stay running, it starts, idles for a few seconds and then acts like it’s running out of fuel and dies. any thoughts? Covid 19 🤣 Quote
tomek Posted January 14, 2022 Posted January 14, 2022 1 hour ago, TFT said: I tried starting it and it won’t stay running, it starts, idles for a few seconds and then acts like it’s running out of fuel and dies. any thoughts? Low speed circuit. It could be number of things. Carb cleaner and compressed air is your friend. Rebuild kit will fix the issue if only pilot jet is blocked. There are 3-4 holes at the bottom of venturi that provide fuel during low load/speed operation. They matter during idle and when you start to open the throttle. The adjustment screw controls only one of them. Anyway, I would completely disassemble carbs, remove bowls, all jets, try to clean it with compressed air and carb cleaner as much as possible. Quote
blackhawkxx Posted January 14, 2022 Posted January 14, 2022 13 hours ago, superhawk996 said: You probably just need to clean the jets. At most you'd need new bowl gaskets, but they often re-seal just fine. This. Don't need anything else as long as one is careful. Quote
superhawk996 Posted January 14, 2022 Posted January 14, 2022 14 hours ago, TFT said: I tried starting it and it won’t stay running, it starts, idles for a few seconds and then acts like it’s running out of fuel and dies. any thoughts? Is this with the choke on? How long was it parked? Quote
TFT Posted January 14, 2022 Author Posted January 14, 2022 (edited) 17 minutes ago, superhawk996 said: Is this with the choke on? How long was it parked? Yes, with choke on. It was parked for at least 6-8 months. The other thing I've been thinking about is the fact that the bike is 25 years old. Maybe it's time to go through the whole thing, flush and change all the fluids and tear down the carbs. It's always been garaged, a heated garage where it spent most of its life until 2019 when I road it down from AK to AZ and then unfortunately in a "heated" garage in AZ during the summer months. It ran great on that trip from AK to AZ but it just hasn't been ridden much since then. Edited January 14, 2022 by TFT Quote
superhawk996 Posted January 14, 2022 Posted January 14, 2022 33 minutes ago, TFT said: Yes, with choke on. It was parked for at least 6-8 months. The other thing I've been thinking about is the fact that the bike is 25 years old. Maybe it's time to go through the whole thing, flush and change all the fluids and tear down the carbs. It's always been garaged, a heated garage where it spent most of its life until 2019 when I road it down from AK to AZ and then unfortunately in a "heated" garage in AZ during the summer months. It ran great on that trip from AK to AZ but it just hasn't been ridden much since then. Giving it a maintenance makeover never hurts, but might not cure the problem depending on what it is. Mine sits for months at a time outside and so far it's been fine. Fuel only flows from the tank while the engine is cranking or running. It'll usually take several seconds of cranking for the carbs to get enough fuel that it'll start, and quite often it'll take a couple more cranks/stalls before it stays running. If after 4-5 stalls it still won't stay running then something's wrong, before that it means nothing. Quote
jon haney Posted January 14, 2022 Posted January 14, 2022 I agree with Tomek on this. Clean, clean, clean. If storing in a hot AZ garage for more than a week or two, I would drain the float bowls. It stored for more than a couple months, use fuel preservative and/or non-ethanol gas. Quote
tomek Posted January 14, 2022 Posted January 14, 2022 (edited) I should have a set of cv carbs laying around at my compound. I'll try to get some relevant pics over the weekend. Also, doesn't xx has one of those vacuum operated petcocks? Maybe bypass it for diagnostic purposes? Edited January 14, 2022 by tomek Quote
TFT Posted January 14, 2022 Author Posted January 14, 2022 1 hour ago, tomek said: I should have a set of cv carbs laying around at my compound. I'll try to get some relevant pics over the weekend. Also, doesn't xx has one of those vacuum operated petcocks? Maybe bypass it for diagnostic purposes? Yep. This bike really hasn't had any major maintenance in the past 15-20 years. Brake fluid change, oil changes, air filters, brake pads, and of course quite a few sets of tires but that has been it. Oh and a CCT replaced as well as a rectifier. Quote
superhawk996 Posted January 14, 2022 Posted January 14, 2022 4 hours ago, jon haney said: If storing in a hot AZ garage for more than a week or two, I would drain the float bowls. It stored for more than a couple months, use fuel preservative and/or non-ethanol gas. Those are the 'right' things to do, but they seem to be unnecessary. Mine sits outside and has seen 30 degrees to well over 100 with E-10 and no prep. It's been a few months so I decided to fire it up. It took just over 10 seconds for the first little sputters to start happening, then at about 15 it briefly started and stopped. It did that a couple more times then stayed running but very rough. A few seconds later it cleared up. Quote
tomek Posted January 16, 2022 Posted January 16, 2022 (edited) I'd try superhawks suggestions first. Many carb bikes do have low pressure fuel pump, and it is possible to fill bowls with fuel by turning key on-off couple of times before cranking the engine, but XX is not one of those. Anyway, pics from Mikuni carbs, should be all about the same. Pics with pilot fuel jet in place and removed. Edited January 16, 2022 by tomek Quote
tomek Posted January 16, 2022 Posted January 16, 2022 (edited) Fuel from pilot jet flows to 4 holes at the bottom. Edited January 16, 2022 by tomek Quote
tomek Posted January 16, 2022 Posted January 16, 2022 Keep the throttle open but sticking something in the other one, remove pilot jet, and spray carb cleaner like in the picture. Quote
tomek Posted January 16, 2022 Posted January 16, 2022 (edited) Remove idle mixture adjustment screw, but before you do it turn it all the way in. Count the turns. You gonna have to reinstall it exactly the same way (turns). Usually it is around 3 turns out from fully turned in position. Clean it with carb cleaner. It will be flowing from just on hole. Carb turning is becoming lost art, but as you can see adjustment screw controls flow only to one of 4 holes on the floor. So, sometimes turning the screw won't fix lean conditions under certain loads, different jet is needed. Edited January 16, 2022 by tomek Quote
tomek Posted January 16, 2022 Posted January 16, 2022 Bowl gasket can be reused about 176 times. 2 Quote
TFT Posted January 16, 2022 Author Posted January 16, 2022 11 hours ago, tomek said: Keep the throttle open but sticking something in the other one, remove pilot jet, and spray carb cleaner like in the picture. Thanks for all the pics and info. I spent most of the afternoon yesterday trying to get the carb bank separated from the engine, I could not break them free and I'm afraid of causing damage. I spoke to the owner of the local motorcycle repair shop and they are going to pick up the bike on Tuesday. Quote
superhawk996 Posted January 16, 2022 Posted January 16, 2022 Sometimes you can clear out the jets by spraying through the air jet so you don't have to take the bowls off. When you look into the carb's air inlet you should have two air jets facing you, I think the larger one is for the idle jet. If you haven't taken everything apart yet you can give that a shot and see if it runs. Quote
brianmacza Posted January 16, 2022 Posted January 16, 2022 What mileage has the bike done? My '97 is on 279k km now, and is using a fuckton of fuel compared to 15 years ago. Took the needles and mainjets and looked at them under a strong magnifying lens and the wear is visible. I have replacement needles and stock mains on order, and waiting for arrival. Might be worth considering if your bike has seen high mileage Quote
blackhawkxx Posted January 16, 2022 Posted January 16, 2022 5 hours ago, TFT said: Thanks for all the pics and info. I spent most of the afternoon yesterday trying to get the carb bank separated from the engine, I could not break them free and I'm afraid of causing damage. I spoke to the owner of the local motorcycle repair shop and they are going to pick up the bike on Tuesday. It is hard to separate, you have to rock them back and forth with some force. Eventually they will come loose. Quote
superhawk996 Posted January 17, 2022 Posted January 17, 2022 My gut's telling me that the problem might be the petcock and not the carbs. Fill them through the hose now that the tank is off and see if it runs. Quote
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