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Discussion Starter · #1 · (Edited)
Several months ago I was riding down the freeway on my 02 V Rod. The engine started acting like it was running out of fuel so I stopped and topped off. When I started it back up it sounded like air was coming back out the top. I started to ride to see what it was doing it would go from full power to hardley any power to just dieing. I towed it home. I then let it sit for several months now due to a motorcycle accident on another bike. I am now able to work on it again. I changed out the plugs and coil pack since the only code was on bank 1. Tried to start it and still getting a air rush coming back through the throttle body. Any help with this would be appreciated?

Video of bike
 

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Several months ago I was riding down the freeway on my 02 V Rod. The engine started acting like it was running out of fuel so I stopped and topped off. When I started it back up it sounded like air was coming back out the top. I started to ride to see what it was doing it would go from full power to hardley any power to just dieing. I towed it home. I then let it sit for several months now due to a motorcycle accident on another bike. I am now able to work on it again. I changed out the plugs and coil pack since the only code was on bank 1. Tried to start it and still getting a air rush coming back through the throttle body. Any help with this would be appreciated?
Lack of combustion code and air blowing back up the intake would indicate a stuck intake valve. Does it run on both cyls or just one? Early v rods had problems with the fuel fitting at the tank, which could explain the running out of fuel effect. Get too lean, it could also miss and throw a combustion code. Really need more detailed explanations. Even that air rushing up the tb could be just normal reversion sounds.
Ron
 

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Discussion Starter · #3 ·
Lack of combustion code and air blowing back up the intake would indicate a stuck intake valve. Does it run on both cyls or just one? Early v rods had problems with the fuel fitting at the tank, which could explain the running out of fuel effect. Get too lean, it could also miss and throw a combustion code. Really need more detailed explanations. Even that air rushing up the tb could be just normal reversion sounds.
Ron
Ron seems like its one cylinder. I grabbed a video of it running so you could hear what its doing as well.
 

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Ron seems like its one cylinder. I grabbed a video of it running so you could hear what its doing as well.
Yup, single cylinder firing. Since you did the coil and plug based on that cyl code, front being #1, what you can do check for lack of fuel or possible injector problem. Take the airbox off and breather. Get it started , like in the vid but just hold it at a steady rpm and have a means to squirt a tad of fuel into each bore. Using the start throttle lock can help dial in a suitable rpm for this. The bore that brings the cyl to life with a squirt is the problem one but the combustion code will point to the correct one as well. Also if you run it a few seconds, the hottest exhaust pipe will be the one actually running. This squirt test can point to a faulty injector or wiring and worse case the ECM. If no joy to get that cyl to fire with a fuel squirt, do a compression test.
Ron
 

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Just be aware that a compression test on early VRSC's are not the same on front and rear cylinders due to the compression release cams. And have caused a few unnecessary engine teardowns due to this. Hope you have a factory manual. It is explained in detail in the manual.
 
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Discussion Starter · #7 ·
Yup, single cylinder firing. Since you did the coil and plug based on that cyl code, front being #1, what you can do check for lack of fuel or possible injector problem. Take the airbox off and breather. Get it started , like in the vid but just hold it at a steady rpm and have a means to squirt a tad of fuel into each bore. Using the start throttle lock can help dial in a suitable rpm for this. The bore that brings the cyl to life with a squirt is the problem one but the combustion code will point to the correct one as well. Also if you run it a few seconds, the hottest exhaust pipe will be the one actually running. This squirt test can point to a faulty injector or wiring and worse case the ECM. If no joy to get that cyl to fire with a fuel squirt, do a compression test.
Ron
Looks like its time for a compression test. Any fuel I get in blows right back out. I can feel considerable amount of air coming back out the front cylinders airintake.
 

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Looks like its time for a compression test. Any fuel I get in blows right back out. I can feel considerable amount of air coming back out the front cylinders airintake.
Hmm. Wondering stuck valve or a shim popped part way out keeping the valve from fully closing even if the valve tried to pop free after. There was considerable valve noise in the vid. Pretty sure the compression test will show 0 in the front cyl. Then it's dive in under the valve cover for a peek.
Ron
 

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Discussion Starter · #9 ·
Hmm. Wondering stuck valve or a shim popped part way out keeping the valve from fully closing even if the valve tried to pop free after. There was considerable valve noise in the vid. Pretty sure the compression test will show 0 in the front cyl. Then it's dive in under the valve cover for a peek.
Ron
Thank you for the help.
 

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Was their any oil pressure issues? I ask because of the blueing if the metal.It also could be that a valve hit a piston.Or the cap bolts came loose.It depends on your knowledge of engine repair. Whether or not to repair it. Probably better off getting a replacement engine. What do the valve stems look like? Did the keepers come out?
 

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More likely that the bolts came loose or snapped due to being overtightened. I had a piston hit a valve at max rpm and it bent the valve like an "S" and shoved it up into the head but there was no damage at all the cam or carriers.
 

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More likely that the bolts came loose or snapped due to being overtightened. I had a piston hit a valve at max rpm and it bent the valve like an "S" and shoved it up into the head but there was no damage at all the cam or carriers.
Yeah more likely loose. Over tight would gave to much crush on cam. Since there are no cam bearings, would surely lock cam .That's why the torque is so little. I over torqued a BMW over head and that cam did not like that at all. Its something it was still running. Might get away with replacing head and drop pan to see how much metal is there.
 

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This is most likely at a torqueing issue or lack of and that 85"lbs is critical for the right amount of bolt stretch. A figure determined by bolt size, thread pitch or the metal it screws into. In therory, one would pull the threads out of the head before the bolt would break if over-tightened and too loose it could pound the threads out or have the bole snap from cyclic tensile loading. There's an odd chance of a defective bolt and if one breaks the other will be taken out from the cyclic bending not long after. That cap took a real shit kicking in there. The amount of damage wasn't instant and took some time to look like that.
Ron
 

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This is most likely at a torqueing issue or lack of and that 85"lbs is critical for the right amount of bolt stretch. A figure determined by bolt size, thread pitch or the metal it screws into. In therory, one would pull the threads out of the head before the bolt would break if over-tightened and too loose it could pound the threads out or have the bole snap from cyclic tensile loading. There's an odd chance of a defective bolt and if one breaks the other will be taken out from the cyclic bending not long after. That cap took a real shit kicking in there. The amount of damage wasn't instant and took some time to look like that.
Ron
(y)
 

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Discussion Starter · #20 ·
No idea. It was a low mileage bike when I got it a 2 years ago. It had around 11000 miles. Now about 17000. I will dig into more next week. I was devastated to see this. Tempted to get a used engine to drop in it and do a tear down later.
This is most likely at a torqueing issue or lack of and that 85"lbs is critical for the right amount of bolt stretch. A figure determined by bolt size, thread pitch or the metal it screws into. In therory, one would pull the threads out of the head before the bolt would break if over-tightened and too loose it could pound the threads out or have the bole snap from cyclic tensile loading. There's an odd chance of a defective bolt and if one breaks the other will be taken out from the cyclic bending not long after. That cap took a real shit kicking in there. The amount of damage wasn't instant and took some time to look like that.
Ron
Last year I had a shop change my shift drum because it was sliding out of 2nd. I know they had to split the case. I don't think they would mess with the cam caps but maybe. Or it has always ran like 💩 since I owned it and I just figured its how it sounded. Frustrating to say the least. I think I will just grab a used engine at this point. It will give me a great parts engine.
 
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