thaykyou for this video. when u removed the 2 caps and gave your bike a vacuum leak the symptoms it produces was exactly how my bike is running so i checked my bike for any leaks and i discovered a few cracks in the inlet manifold
Thanks it did help a lot - And for Carb based systems. I have a vintage CB750, and have done a lot of work on her. Everything seemed okay today, until on the way home breaking 90MPH. Cylinder 1, if on my right backfires , and suddenly idling down to stall when exiting freeway. All new boots were added 1,000 miles before. I'm going to check them again, but wonder if Carb 1 is fouling from some dirt. I used Sea foam in my tank not so long ago, and Carb 4 if on my left, fuel bowl jam'd causing over flow. The solution was to drain that bowl and under pressure, direct carb cleaner into the fuel bowl using the over flow tube as the means to blow it in. Eventually it worked, and the Fuel bowl level was freed up with out disassembling the carb. After tearing her down so many times, if I can avoid it, that's what ill try first -
FYI - I blew into the fuel bowl with the carb cleaner direct as described earlier. With her becoming more civilized, I added STP Ultra and just returned from a ride on Rt1 No misfires under demand. - Power is back. I got to adjust idle mixtures again, as leaned them for debugging. Top operating case temp in 75 degrees is 180 degrees F. Not sure what the operating temp of the case should be normally - be well -
Out of any video to show me what i’ve been pulling my hair out over on my 1987 monte carlo ss, it’s a motorbike video, I love it 😆 atleast i’m a little closer to figuring out what’s wrong.
Yes, because starting requires a lot of fuel, but if theres a leak too much air will get in, if its a small leak it wont change much, but if its a big tear it will have a hard time starting
would this effect when running e.g with mine since i changed jet if i say hold at 30% throttle it will rev as it should but go say 20mph after about 5 seconds it will kick in and run as normal maybe i have a vaccum leak?
Question: If my bike had a vacuum leak, after the engine has warmed up, when I throttle it without opening the choke, the engine will die, open the choke and it is ok, is this vacuum leak? And I just cleaned the carburetor, so no problem with carb.
I'm pretty out of practice these days with carbs but if memory serves, you could have a plugged pilot jet even though you've cleaned the carb. It's common practice to replace the pilot even if you think it's clean. Most of my carb experience when they don't work right is with single Cylinder.
After watching my video again you are describing the symptoms of a vacuum leak. Unfortunately even if you have a leak, my video doesn't help you find it. I'm sure other video show best practices for tracking down the location of a leak.
If someone has recently worked on the bike then check all the hoses related to that service. Other than that you just need to start checking every hose for loose ends or cracks. Sadly I don't think you can use soapy water for this because it won't bubble due to the negative pressure on the hoses. Like the comment below, you just have to search around.
@@rojoracing53 thanks a ton. It was giving me symptoms of a bad carb so I've cleaned it SO GOOD! cleaned it 4 times and had a shop clean it as well with the same result. We finally came to the conclusion today it's a vaccume leak. Ugh the hunt continues lol
You could take a propane torchs fumes without igniting it around the carbs and boots. Same with carb cleaner. If there is a leak it should change the RPMs in a noticeable way.
I would say no, the most noticeablesymptomsis going to be around idle. It may cause a tiny reduction in power but I doubt any of us would feel it. Once you on the throttle they seem fine.
@@rojoracing53 dang well I just found my spark plugs are black not sure if it’s from oil or uncombusted fuel. I was cleaning the carbs and I think the float bowl was sending any carb cleaner right into the engine so when I tried to start it it wouldn’t turn. Took plugs out and turned it over to shoot it out then put them back in and it started fine. But hoping I didn’t do damage because im worried it’s using oil. I’m learning a lot of this stuff on the fly so hopefully it’s not going to cost me this much. Waiting to get adapter for my compression tester
2011 Ninja 250 but with an aftermarket Koso gauge. I don't recall the exact Koso model but it's a universal cluster that can be used with various bikes. Along with my Dual HID projector kit they are my two favorite mods to that bike which are both practical and look amazing.
GuitarMoto Vlogs There are a great many things in my life I should address, TH-cam video titles are very high on that list :lol Next you'll be requesting I add proper word tags and place the video in the instructional category instead of comedy which it defaults to 🤷♂️ Thanks 👍
rojoracing53. No lol, I just came across it from some other video, you explain it well and better than most videos ive seen on youtube and actually show the difference. Im sure its gonna help some more poeople out ;)
![โรงเรียนดัดสันดาน นักเรียนเถื่อน..!! [โรงเรียนไดเม่]](http://i.ytimg.com/vi/vRKPeXn4Fl4/mqdefault.jpg)
Wow, this EXACTLY how my bike is running. This proves the vacuum leak! Thanks
test with brakecleaner to find out there u got the vacuum leak
thaykyou for this video. when u removed the 2 caps and gave your bike a vacuum leak the symptoms it produces was exactly how my bike is running so i checked my bike for any leaks and i discovered a few cracks in the inlet manifold
Thanks it did help a lot - And for Carb based systems. I have a vintage CB750, and have done a lot of work on her. Everything seemed okay today, until on the way home breaking 90MPH. Cylinder 1, if on my right backfires , and suddenly idling down to stall when exiting freeway. All new boots were added 1,000 miles before. I'm going to check them again, but wonder if Carb 1 is fouling from some dirt. I used Sea foam in my tank not so long ago, and Carb 4 if on my left, fuel bowl jam'd causing over flow. The solution was to drain that bowl and under pressure, direct carb cleaner into the fuel bowl using the over flow tube as the means to blow it in. Eventually it worked, and the Fuel bowl level was freed up with out disassembling the carb. After tearing her down so many times, if I can avoid it, that's what ill try first -
FYI - I blew into the fuel bowl with the carb cleaner direct as described earlier. With her becoming more civilized, I added STP Ultra and just returned from a ride on Rt1 No misfires under demand. - Power is back. I got to adjust idle mixtures again, as leaned them for debugging. Top operating case temp in 75 degrees is 180 degrees F. Not sure what the operating temp of the case should be normally - be well -
My sportster does the same but only when it's hot. Great video brother.
So then you have a crack in something that only expands when it gets hot and starts sucking air it's not supposed to?
@@rojoracing53 yeah I think so brother. That was what was confusing me because it only happens after its warmed up.
Out of any video to show me what i’ve been pulling my hair out over on my 1987 monte carlo ss, it’s a motorbike video, I love it 😆 atleast i’m a little closer to figuring out what’s wrong.
Apart from my bike being fuel injected, it is exactly how my bike died. I have just ordered some new hose. They are silicone so should be more durable
Can a vacuum leak prevent your bike to start? Is it possible?
Yes, because starting requires a lot of fuel, but if theres a leak too much air will get in, if its a small leak it wont change much, but if its a big tear it will have a hard time starting
So i have a gilera runner 180cc that starts but as fast as i start it it revs and accelerates away could that possibly be a vacuum leak?
would this effect when running e.g with mine since i changed jet if i say hold at 30% throttle it will rev as it should but go say 20mph after about 5 seconds it will kick in and run as normal maybe i have a vaccum leak?
Question: If my bike had a vacuum leak, after the engine has warmed up, when I throttle it without opening the choke, the engine will die, open the choke and it is ok, is this vacuum leak? And I just cleaned the carburetor, so no problem with carb.
I'm pretty out of practice these days with carbs but if memory serves, you could have a plugged pilot jet even though you've cleaned the carb. It's common practice to replace the pilot even if you think it's clean.
Most of my carb experience when they don't work right is with single Cylinder.
After watching my video again you are describing the symptoms of a vacuum leak. Unfortunately even if you have a leak, my video doesn't help you find it. I'm sure other video show best practices for tracking down the location of a leak.
@@rojoracing53 My previous carburetor cleaning had 2 plugged jets, it was already fix 3 weeks ago, I don't think it will plug up again so fast.
@@rojoracing53 Thanks anyway.
Any suggestions on how to find the vacuum leak?
If someone has recently worked on the bike then check all the hoses related to that service. Other than that you just need to start checking every hose for loose ends or cracks. Sadly I don't think you can use soapy water for this because it won't bubble due to the negative pressure on the hoses. Like the comment below, you just have to search around.
@@rojoracing53 thanks a ton. It was giving me symptoms of a bad carb so I've cleaned it SO GOOD! cleaned it 4 times and had a shop clean it as well with the same result. We finally came to the conclusion today it's a vaccume leak. Ugh the hunt continues lol
You could take a propane torchs fumes without igniting it around the carbs and boots. Same with carb cleaner. If there is a leak it should change the RPMs in a noticeable way.
thanks i wanted to change my carburator but now i know i dont need to
Would this also cause no power over 4k rpm
I would say no, the most noticeablesymptomsis going to be around idle. It may cause a tiny reduction in power but I doubt any of us would feel it. Once you on the throttle they seem fine.
@@rojoracing53 dang well I just found my spark plugs are black not sure if it’s from oil or uncombusted fuel. I was cleaning the carbs and I think the float bowl was sending any carb cleaner right into the engine so when I tried to start it it wouldn’t turn. Took plugs out and turned it over to shoot it out then put them back in and it started fine. But hoping I didn’t do damage because im worried it’s using oil. I’m learning a lot of this stuff on the fly so hopefully it’s not going to cost me this much. Waiting to get adapter for my compression tester
Can vacuum leaks cause revs hanging for about 2 seconds and then dropping after revving
Jom - your running lean. I have that on my 2 stroke
It can possibly
I have the same thing I was thinking to a vacuum leak too... Have u found the price problem?
@@razvan3974 yeah just check all carburetor gaskets and if they all are ok switch your main jet to a bigger one
@@razvan3974 and by carburetor gaskets i mean the float bowl and intake manifold
will the bike bog if there is a leak in the airbox ?
Sarem define "in airbox"?
If it's just air leaking into the air box cavity where your filter is then no that won't cause this bogging.
what was the census ?
What is that bike, i like the speedometer a lot
2011 Ninja 250 but with an aftermarket Koso gauge. I don't recall the exact Koso model but it's a universal cluster that can be used with various bikes. Along with my Dual HID projector kit they are my two favorite mods to that bike which are both practical and look amazing.
You should title this "vacuum leak symptoms"
GuitarMoto Vlogs
There are a great many things in my life I should address, TH-cam video titles are very high on that list :lol
Next you'll be requesting I add proper word tags and place the video in the instructional category instead of comedy which it defaults to 🤷♂️
Thanks 👍
rojoracing53. No lol, I just came across it from some other video, you explain it well and better than most videos ive seen on youtube and actually show the difference. Im sure its gonna help some more poeople out ;)
@@CheapGuitarsAndMore it proved to work because that's how I got here
Thanks :)