Cold start, top of engine knocking/clanking but not on warm start?

[Extram]

So I have an '88 Vmax with 61.8k miles on it and about a month ago I dropped the bike going about 10 MPH on a turn (thanks sand lol) and ever since then when the bike hasn't been turned over in more than a day then when I put the key in the ON position and the killswitch to run then when it does its startup sequence there is a very loud and audible knocking/clanking sound coming from the top of the engine. I can still start it up fine, it runs perfect, no smoke, and it's been running great other than this little issue. I've been meaning to make a video on the noise but every single time I try to take a video of it, it of course, doesn't make any knocking sound. I'll keep trying to make one and then edit the link into here but have any of you heard of something like this? Any ideas on what it could be?

Just to clarify, these noises are only heard when the bike is OFF and not running; and they are coming from the top of the engine. I can hear it for about 2-3 seconds and then it is gone. Thanks!

 

[jfeagins]

Either your fuel pump, or your Vboost linkage has developed an issue since your spill.

They would both be heard when first turning on your bike. The pump, only if it needs to build pressure. The Vboost cycles each time the key is turned on.

 

[Extram]

Either your fuel pump, or your Vboost linkage has developed an issue since your spill.

They would both be heard when first turning on your bike. The pump, only if it needs to build pressure. The Vboost cycles each time the key is turned on.

How hard would it be to check these? I know a little bit about motorcycle engine work but if it involves me completely tearing apart the upper half of the motor then I think I'll leave it to the mech

EDIT: This is the exact sound it is making, thanks for letting me know about the possibilities! https://www.youtube.com/watch?v=SrAkTJx9VIc

 

[jfeagins]

All I can hear in your video is the fuel pump clicking non-stop. It will only click for so long each time the key is turned on, then it's relay will stop it from going further. Then you'd need to turn off the key, and turn it back on for the pump to continue trying to build pressure.

If that clicking is what you are talking about, then most likely, one, or both, of the tiny little rubber diaphragms inside your pump got jarred loose from their proper mounting position when you dumped your bike. If that is the case, a quick dismounting of the fuel pump, and disassembly of the pump end will get you access to the two diaphragms. Each one will have a small rubber "diddy" sticking out of one side, that would need to be pushed back into the center hole from where it is located....in order for the pump to pull any fuel from the tank, and to build pressure. Sometimes only one diaphragm is dislocated, and the pump will still build pressure, but would have to work harder to keep up with enough fuel to go down the hwy.

 

[Extram]

All I can hear in your video is the fuel pump clicking non-stop. It will only click for so long each time the key is turned on, then it's relay will stop it from going further. Then you'd need to turn off the key, and turn it back on for the pump to continue trying to build pressure.

If that clicking is what you are talking about, then most likely, one, or both, of the tiny little rubber diaphragms inside your pump got jarred loose from their proper mounting position when you dumped your bike. If that is the case, a quick dismounting of the fuel pump, and disassembly of the pump end will get you access to the two diaphragms. Each one will have a small rubber "diddy" sticking out of one side, that would need to be pushed back into the center hole from where it is located....in order for the pump to pull any fuel from the tank, and to build pressure. Sometimes only one diaphragm is dislocated, and the pump will still build pressure, but would have to work harder to keep up with enough fuel to go down the hwy.

It's actually not my video just one I stumbled upon when I searched up faulty vmax fuel pump. The sound only occurs for about 3 seconds and then shuts off even with the key still on. Looks like this is going to be my little weekend project haha. Thanks for all your help!

 

[jfeagins]

If hearing the fuel pump click for only 3 seconds when first turning on your key, and it doesn't do that seconds later when trying it again,

go ride it and stop worrying!

Seems normal to me.

 

[blaxmax]

Your fuel pump cycles when you first turn the key on as it is filling your fuel bowls with gas. If you turn it on a few seconds later it will click less. Turn it on a few seconds later and eventually it will stop cycling as the bowls are full.

 

[Traumahawk]

If hearing the fuel pump click for only 3 seconds when first turning on your key, and it doesn't do that seconds later when trying it again,

go ride it and stop worrying!

Seems normal to me.

+1

or I guess that is

+1

 

[Extram]

If hearing the fuel pump click for only 3 seconds when first turning on your key, and it doesn't do that seconds later when trying it again,

go ride it and stop worrying!

Seems normal to me.

Welp. I did just that. Took it out for a spin for about an hour and it died on me. I was having issues with it when it gets a little bit hotter than usual (right below the dot for the fan to come on) my throttle would bog down and shut off the bike. Then I couldn't get it started and the battery died on me. Yay for my luck .

 

[wildweasel_pt]

Clacking noise like said already is fuel pump priming carbs bowls. It does until the bowls are full or up to 5/7 seconds and then the fuel pump relay should turn it off. The second issue looks like the dreadful charging issue. Look on forum for that in the electrical section. All the answers are there.

 

[jfeagins]

.... The second issue looks like the dreadful charging issue. Look on forum for that in the electrical section. All the answers are there.

Yup!