It sounds like your idling circuit is involved have you done any adjustments to the air/fuel mixture screws. Check your air filters to be sure there clean and re oiled . Have you been riding it much since this condition started.? Look for the simple solutions first.
1989 Vulcan 750 running problem (sort of)
Goodnight everyone, I’m having a problem with our Vulcan 750. Right now the temps are around 75-83 degrees F. So no choke is needed. Bike starts up, jumps up to 3k rpm’s and instantly drops rpm then dies, bike will stay running if I have my hand on throttle.
I’m not sure if the bikes getting too much air or something like that. Any tips?
I’m not sure if the bikes getting too much air or something like that. Any tips?
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This bike hasent been on the road since 1999, it was just stored away under tarps outside and inside the garage. I started working on it last year and I got it to run well. As soon as I put in the air ducts on the bike, it started to have problems starting. Right now it will start then it doesn’t want to idle. Could it be too much air getting it? Should I tighten the rubber boots that mount the carb to the engine? I’m not sure but I really want to work on this and fix it quick. Thank you!
Maybe try to check for any leaks around the boots when the bike is running. If the bike has sat for this long, perhaps the carbs would have to be pulled out and cleaned? But first take care of one thing at a time and try to make sure everything looks good. Air filters are clean and oiled like Buddy said. Intake plenum is all attached and tight. No boot leaks. Then we can move on to talking about the carb itself.This bike hasent been on the road since 1999, it was just stored away under tarps outside and inside the garage. I started working on it last year and I got it to run well. As soon as I put in the air ducts on the bike, it started to have problems starting. Right now it will start then it doesn’t want to idle. Could it be too much air getting it? Should I tighten the rubber boots that mount the carb to the engine? I’m not sure but I really want to work on this and fix it quick. Thank you!
Well the bike doesn’t have any leaks, last summer I got the bike fully running good, carb was already rebuild with new jets that are the correct size, cleaner and everything like that. I don’t think there’s any leaks around the boots, when I put the air ducts in that’s when I started having starting problems. I took it back out and I’m still having the problem. I’m highly sure it’s because the car duct needs to be tightened. It probably moved a little which is throwing everything off.
Great!! Good to know there's no leaks and the carb has been cleaned and such. That rules out a lot! Definitely get in there to secure down that duct and see if that is the issue. You'd be surprised as to how a tiny air leak thru a loose duct could screw things up. But that could be your cause. And if not, come back here to the brain trust and we can think about other possiblities. Remind me, have you checked the condition and gap of your spark plugs? And do you have nice fresh fuel also?Well the bike doesn’t have any leaks, last summer I got the bike fully running good, carb was already rebuild with new jets that are the correct size, cleaner and everything like that. I don’t think there’s any leaks around the boots, when I put the air ducts in that’s when I started having starting problems. I took it back out and I’m still having the problem. I’m highly sure it’s because the car duct needs to be tightened. It probably moved a little which is throwing everything off.
fuel is nice and fresh, has some fuel from a few months ago but I put some fresh fuel in. But with that fuel it ran perfect. I’m gonna add some stabilizer most likely. I hope it doesn’t rurine anything because I know these bikes are really picky. I will tighten the rubber boot later, should I reconnect the air duct that go on the carb to the surge tank?
I'm not great with carbs/air-fuel mix issues, but it seems like if it was working OK without the air ducts installed, then you added the filters on, then your issue is an air restriction/rich mix. If you pull the filters out of the pods, does it run OK again?This bike hasent been on the road since 1999, it was just stored away under tarps outside and inside the garage. I started working on it last year and I got it to run well. As soon as I put in the air ducts on the bike, it started to have problems starting. Right now it will start then it doesn’t want to idle. Could it be too much air getting it? Should I tighten the rubber boots that mount the carb to the engine? I’m not sure but I really want to work on this and fix it quick. Thank you!
Air leaks are a problem, and loose carb boots have caused lean mix issues, but it doesn't seem like that would be the problem if it was running OK without the ducts installed, as you'd be having a ton of air flow.
I wish that would solve the problem but right after that I took it out. I could see the carb shift a little and slip back into its spot but that could have make the carb fit in loosely. I will have to tighten it. I’m not sure if I should put the air ducts back on and tighten the carb rubber boots or should I just tighten the rubber boots and get the bike running first. I will probably do the second choice.I'm not great with carbs/air-fuel mix issues, but it seems like if it was working OK without the air ducts installed, then you added the filters on, then your issue is an air restriction/rich mix. If you pull the filters out of the pods, does it run OK again?
Air leaks are a problem, and loose carb boots have caused lean mix issues, but it doesn't seem like that would be the problem if it was running OK without the ducts installed, as you'd be having a ton of air flow.
Didn't see that you'd tried again with the ducts removed again. Does sound like a carb boot leak that opened up when you were jamming the air ducting into place. People will spray starter fluid around the boots to see if it'll get sucked in/enrichen the mix to diagnose an air leak. I've never done it, but it would be something to search for.when I put the air ducts in that’s when I started having starting problems. I took it back out and I’m still having the problem.
Yes, exactly this. I'd recommend trying this also. And goodluck, please do keep us posted. You'll get your Vulcan running.Didn't see that you'd tried again with the ducts removed again. Does sound like a carb boot leak that opened up when you were jamming the air ducting into place. People will spray starter fluid around the boots to see if it'll get sucked in/enrichen the mix to diagnose an air leak. I've never done it, but it would be something to search for.
Before you were having no issues other than the bike would start runs a 3000 RPM and then shut you off. You pulled and returned the air boxes and the issue got worse with the possible cause that the vent hose that connects under the search tank that runs to the air shut off valve could be completely out of it or loose, you need to go through these things one of the time to try to keep things simple fix one thing and then move onto the next. Keep us posted cause I’m very curious with this.
Good News. I actually did not see this message, the hose clamps for the carb were loose that mounts it to the bike. I tightened them up and the bike is running good. For like a minute the bike was running really rough then it cleared its self up. I messed with the idle control so it shot up to 4k rpms. After that I shut the bike off. A little leak from the petcock. Its not even dripping but I just need to tighten it. Besides that I will try to mount the air boxes again, everything is connected and is tight at the Air shut off valveBefore you were having no issues other than the bike would start runs a 3000 RPM and then shut you off. You pulled and returned the air boxes and the issue got worse with the possible cause that the vent hose that connects under the search tank that runs to the air shut off valve could be completely out of it or loose, you need to go through these things one of the time to try to keep things simple fix one thing and then move onto the next. Keep us posted cause I’m very curious with this.
Good to hear I told you look for the simple stuffGood News. I actually did not see this message, the hose clamps for the carb were loose that mounts it to the bike. I tightened them up and the bike is running good. For like a minute the bike was running really rough then it cleared its self up. I messed with the idle control so it shot up to 4k rpms. After that I shut the bike off. A little leak from the petcock. Its not even dripping but I just need to tighten it. Besides that I will try to mount the air boxes again, everything is connected and is tight at the Air shut off valve
I paid like $30 for the air ducts used on eBay because I don’t even think you can buy things for this bike brand new like mirrors, etc. But I do want to get the bike running with it because I can’t just leave it open. Maybe the bike was just like running then dying out because when I put the air ducts it, it shifts the carb introducing more air into the engine without enough fuel to compensate for it.
I can’t post a video because it won’t let me but the bike is going up in rpm by itself.. not sure why. Kinda scaring me. Anyone have any reasons why it may or solutions?
Air leak!I can’t post a video because it won’t let me but the bike is going up in rpm by itself.. not sure why. Kinda scaring me. Anyone have any reasons why it may or solutions?
Do you know where the air leak may be?Air leak!
Could be air cut off valve in front of battery it has 5 or 6 hoses attached to it I had mine go bad and throttle would act crazy
So you’re saying that this needs to be replaced? I’m pretty sure all the hoses are connectedCould be aid cut off in front of battery it has 5 or 6 hoses attached to it I had mine go bad and throttle would act crazy
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