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98’ 1200 - Engine bogging on acceleration after oil change
Hey guys, I’m a second year rider so I can say, I’m pretty damn new to working on Harley’s. Ran into an issue after changing the oil, where the bike will sputter and lose power after anything more then just a slight crack on the throttle.
Gonna run through the carb tonight, but I feel like this might be a problem related to the VOES? It was connected to the carb, and the other line that’s supposed to go to the petcock was disconnected - and the petcock that is on it now doesn’t have nipple for the hose. I plugged it?
Also found another line that’s cracked and old and looks important-ish.
I know just enough to get most things running, but I’m in a little over my head without enough money to take it to the shop.
Add some details. I assume it was running OK before maintenance. What did you do besides oil.
Be sure to make your next new post over in the new member area.
Just in case.
Welcome from North Beach, FL., USA!
Just in case you have not done this.
Add a Signature Line in your USER set up for your bike year, model, and all the letters that Harley recognizes it with so others see at the bottom of all your post. This enables others to know your exact model if you ever ask a question.
And an Avatar of your favorite shot in the USER set up for the small picture others will see in the top left corner of your post.
Your all set.... Enjoy the ride! ______________
Last edited by Jackie Paper; May 31, 2022 at 07:16 PM.
The line in your hand looks like some type of a breather vent line, but not really sure. Was it used to vent the top end to the rear of the bike? You have a screamin eagle after marker head breather vent (that chrome tube that connects to both of the heads) so it might have been attached to that short nipple on the chrome tube (however that is the wrong way to do it if that is the case). The vent line for the head breathing should go straight down.
Your petcock is the non vacuum type so the only vacuum line you need comes from a small nipple on the carb (or sometimes from a small nipple on the manifold). So plugging the stray end or just running one hose from the small nipple on carb (or manifold) to the voes is what I would do.
Have you done anything else to the carb before this problem started?
An oil change should not cause your carb symptom so fix the voes plumbing and go from there.
The cross over between the two cylinders should be disconnected, why?? Because the pistons in a HD move up and down together, with that setup there is no where for the crankcase to breath. Otherwise you will blow all the seals out of the crankcase and the Primary/Transmission will be "making oil".
The fuel line as connected should be taken off and thrown in the trash, replace with just one fuel line to the carb.
The petcock was put on incorrectly and is leaking, remove the nut by turning in the correct direction, you will notice there is a fiber washer between the petcock and tank or at least there should be one. Now, the nut has both left and right handed threads in it, to get a good connection both the petcock and tank should be started at the same time so as the nut is pulling the two together it will compress the fiber washer and there will be a thread or two exposed both on the tank and petcock.
The hose you are holding is the vent breather line for the fuel tank or possibly a vent to a charcoal container for the "California" emissions requirement. Not needed but make sure the tank is vented.
Do what Yankee Dog says about the VOES. (Vacuum Operated Electrical Switch) It advances the timing after the engine is started.
Add some details. I assume it was running OK before maintenance. What did you do besides oil.
Yeah, everything seemed fine before maintenance, just did a standard oil change. Drained the oil, swapped and filled new filter, replaced plug, and then threw three quarts in.
Originally Posted by Yankee Dog
The line in your hand looks like some type of a breather vent line, but not really sure. Was it used to vent the top end to the rear of the bike? You have a screamin eagle after marker head breather vent (that chrome tube that connects to both of the heads) so it might have been attached to that short nipple on the chrome tube (however that is the wrong way to do it if that is the case). The vent line for the head breathing should go straight down.
Your petcock is the non vacuum type so the only vacuum line you need comes from a small nipple on the carb (or sometimes from a small nipple on the manifold). So plugging the stray end or just running one hose from the small nipple on carb (or manifold) to the voes is what I would do.
Have you done anything else to the carb before this problem started?
An oil change should not cause your carb symptom so fix the voes plumbing and go from there.
So, there's a separate breather tube that comes down off the header vent that tucks down by the oil drain hose, so that might be too long.
Pretty sure the line in my hand is a fuel breather vent like Kabear says. Kinda looks like the tank might have been swapped out? I'll make sure the tank is vented either way.
I only changed the oil, but the guy who put the filter on before me did so with malicious intent - broke a strap wrench and bent a socket style filter wrench before driving to my buddies shop to get the proper tool - which barely worked.
The bike is tore apart now, about to clean and then possibly rebuild the carb depending what shape it's in - BUT before I did that, I plugged the stray line and recognized the same symptoms.
Gonna test the VOES with my voltmeter to see if its working, and then I think I'll buy a fresh line without a Y for it as I'm putting things back together.
Originally Posted by Kabear
The cross over between the two cylinders should be disconnected, why?? Because the pistons in a HD move up and down together, with that setup there is no where for the crankcase to breath. Otherwise you will blow all the seals out of the crankcase and the Primary/Transmission will be "making oil".
The fuel line as connected should be taken off and thrown in the trash, replace with just one fuel line to the carb.
The petcock was put on incorrectly and is leaking, remove the nut by turning in the correct direction, you will notice there is a fiber washer between the petcock and tank or at least there should be one. Now, the nut has both left and right handed threads in it, to get a good connection both the petcock and tank should be started at the same time so as the nut is pulling the two together it will compress the fiber washer and there will be a thread or two exposed both on the tank and petcock.
The hose you are holding is the vent breather line for the fuel tank or possibly a vent to a charcoal container for the "California" emissions requirement. Not needed but make sure the tank is vented.
Do what Yankee Dog says about the VOES. (Vacuum Operated Electrical Switch) It advances the timing after the engine is started.
Thanks for the heads up, I hear there's a different style breather I can use - I think I figured out why it was put on the bike in the first place via the single comment on this Revzilla post. The breather hose that's on it now has signs of oil leaking out of it.
If I were to disconnect it - would that be it? - Or should I get the other style breather? Would prefer to have my seals intact.
Before I saw this, I actually bought some more fuel line to replace the absolute nonsense that was the fuel line. - I'll pull apart the petcock and put it back together tonight.
Add some details. I assume it was running OK before maintenance. What did you do besides oil.
Yeah, everything was peachy before maintenance. However, I did have to take my bike to my buddies shop to get the oil filter off because it was tightened with malicious intent.
-drained the oil
-broke a strap wrench and a socket style filter wrench trying to get the filter off
-plugged drain hose and filled oil w/ 3 quarts
-drove it 25 mins to my buddies, started noticing a little bogging down
-filled and replaced filter after removing the angry man's filter
-pulled the oil drain one more time to see if there was any air trapped and then sealed
-drove home and noticed the bogging was getting worse -it continued to be worse
Originally Posted by Yankee Dog
The line in your hand looks like some type of a breather vent line, but not really sure. Was it used to vent the top end to the rear of the bike? You have a screamin eagle after marker head breather vent (that chrome tube that connects to both of the heads) so it might have been attached to that short nipple on the chrome tube (however that is the wrong way to do it if that is the case). The vent line for the head breathing should go straight down.
Your petcock is the non vacuum type so the only vacuum line you need comes from a small nipple on the carb (or sometimes from a small nipple on the manifold). So plugging the stray end or just running one hose from the small nipple on carb (or manifold) to the voes is what I would do.
Have you done anything else to the carb before this problem started?
An oil change should not cause your carb symptom so fix the voes plumbing and go from there.
Yeah, I did a little digging after seeing your comment and Kabear's comment - pretty sure its a disconnected fuel vent line. The tank doesn't have a spot for the breather to plug into which means I probably have a different tank.
I'll make sure the tank is vented properly before firing again.
The breather system has a larger hose connected to it, that runs down by the oil drain hose. and it appears to have leaked some oil at some point.
As far as the VOES goes ~ Before I tore the bike apart, I plugged the other hose and ran it and noticed nothing changed. I tested the voes with a voltmeter this morning and it seemed to be working properly - gonna remove the Y and reinstall. Also gonna rip into the carb today and clean everything up, make sure the float is floating.
The weird part is, was that the oil change was the only thing that I did before the bike started running like garbage
Originally Posted by Kabear
The cross over between the two cylinders should be disconnected, why?? Because the pistons in a HD move up and down together, with that setup there is no where for the crankcase to breath. Otherwise you will blow all the seals out of the crankcase and the Primary/Transmission will be "making oil".
The fuel line as connected should be taken off and thrown in the trash, replace with just one fuel line to the carb.
The petcock was put on incorrectly and is leaking, remove the nut by turning in the correct direction, you will notice there is a fiber washer between the petcock and tank or at least there should be one. Now, the nut has both left and right handed threads in it, to get a good connection both the petcock and tank should be started at the same time so as the nut is pulling the two together it will compress the fiber washer and there will be a thread or two exposed both on the tank and petcock.
The hose you are holding is the vent breather line for the fuel tank or possibly a vent to a charcoal container for the "California" emissions requirement. Not needed but make sure the tank is vented.
Do what Yankee Dog says about the VOES. (Vacuum Operated Electrical Switch) It advances the timing after the engine is started.
Thanks for looking out, would prefer to keep my seals intact. I noticed a comment on this part on another website that leads me to believe it was put on there for a reason, and he mentions a different style that might be a better option.
If you have the problem of a messy oil filter that drips oil all over the side of the engine, exhaust, and oil tank, breathers like this are kind of a band aid. Yes, they work in the sense there's no mess on the side of your bike. The problem with the "horseshoe" style is they route the output down, not up, so eventually the oil mist just drips out onto the ground. Even with a little filter, it will quickly saturate and drip out, especially with a big-bore engine or aggressive, high RPM running. Then when it leaves drips on the ground all your friends will make fun of you for having a leaking Harley.
The style with individual banjo bolts you can rotate upwards, run the hose up under the tank are a lot cleaner looking since you don't have to run 3' of hose around the engine and under the bike, don't drip, and can be hidden up underneath the tank.
Before reading your comment I purchased more fuel line to replace the nonsense that is that hose job. Gonna fix the petcock situation, and I think I have a handle on the VOES as well, tested it this morning.
OK, gonna clarify, and not speaking for anybody else, but that chrome screamin eagle crossover tube is a necessary aftermarket (harley) part for the purpose of venting the engine. It has a nipple on it that can't be seen in the pic. That nipple has a hose that vents to the ground.
So it is a necessary breather vent system, just a different version than the OEM factory set up that vents into the air cleaner housing and eventually back into your carb/intake/engine. I have the same one on my bike and has the same set up as skaai.
It can be considered normal to get a drop or two of oil from the down tube/hose that goes to just below the frame. Especially if you keep the oil on the upper level of full, or with "spirited riding" or with umbrella valves that are getting old (rubber umbrella valve getting a little stiff with age)
As far as routing the "vent hoses up", I am not a fan. The hoses will eventually fill with oil/water mix, then what? Let it sit in the hose? Let it build up enough that it eventually dribbles back into the cylinder head eventually goes back up into the top end? Or does it eventually spit out under your tank? I don't know, I am just speculating... I will live with a drop or two of oil coming from the end of the down tube at the end of my ride.
New fuel hose, tested voes, removed voes y split and replaced w/ new line, rebuilt carb - still performing the same way. Sputters, loses power, and dies on any more than a little throttle, but idles perfectly fine.
I did notice that the carb needle was shimmed, I left it that way, there was three little washers on the pin which has an adjustable clip, which seemed weird.
I think my tank has a vented cap, I didn't see anywhere to vent it from, so I'm pretty sure it isn't stock. If I can't figure it out by the end of the weekend, I'll take it to a shop - reluctantly
@Yankee Dog I'll definitely just keep the breather set up.
Any help is appreciated, grasping at straws at this point.
Check the routing of your fuel line from the petcock to the carb. If it passes to close to the head it will heat up and vapor lock, shutting off the fuel flow. Once the engine cools down it will allow fuel to flow again and the engine will fire right up.
Usually the bike has to be driven at least a couple miles for this to happen.
Usually a needle with the clip is a dynojet set up. The best thing you can do is switch back to oem setup. However with the dynojet, the bike should run, but they run really rich. Switching back to oem requires a new emulsion tube and main jet, along with a new needle. Check out CV performance for parts. I would say about a 180 main and a 45 slow jet, and a n65 needle.
But again getting into the carb does not explain your problem of a "no start" after an oil change. The oil change has nothing to do with it unless you accidently did something and you are unaware of it.
Did you do any carb work before the no start problem or after? Is the carb getting a good flow of fuel? With the fuel line disconnected at the carb, open the petcock and watch for flow. Any holes in the carb diaphragm or a pinched diaphragm? Hold diaphragm up to the light to look for holes.
A common mistake people make is they either lose the needle jet, or install the needle jet upside down. Look at an exploded diagram of the cv40 to confirm what the needle jet is. It is not the same thing as the main jet. CV performance also has pics of the carb parts.
How did you test the voes? Bike would still run with voes connected or not. Any vacuum leak at the voes?
Do you have spark at both plugs? Think basics: fuel, spark, compression.
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98’ 1200 - Engine bogging on acceleration after oil change
