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Rod knocking? lmao fml....

9K views 63 replies 12 participants last post by  SmittySmithsonite 
#1 ·
So now that I have my vstar 1100 running perfectly and nice and quiet, i can now hear a very subtle quiet knocking coming from the engine. Doesn't happen all the time, only during certain rpms. Like when cruising in third gear in town, at a certain speed/rpm, i'll start to hear the very faint noise of knocking. Also, not a knocking from lugging the engine.

Sooooo is it a rod knocking? And if it is a rod knocking, would it only happen during certain rpms? Like i said, it comes and goes, and i only hear it because i'm ocd with my bike and how it sounds lol. When it happens, if i keep it at the same rpm, it will continue knocking. If i increase/decrease the throttle even by a little bit, it goes away.
 
#44 ·
your in ontario i would keep the 10/ 40 unless it's going to stay in the 80s. i'm across the lake in erie and i run 20 50 in the heat of the summer. you should be 2 turns out with stock bike. my bike came stock at 1 3/4 out.i would recheck the valves altho there probably ok. and go over the carbs again. check .rubber caps..check clutch adjustment i never heard of shifting problems.
 
#45 ·
Okay on the oil part!

I had the bike initially at 2 turns out and it ran so much better on the day I turned them out a quarter turn extra. I can check the valves again just to make sure since it's been a week or two since I adjusted them

I don't think it's a clutch cable because it only shifts rougher when my actual power loss happens. They are hand in hand together. When it runs good, it shifts good. When it runs poor, it shifts poor.
 
#50 ·
Bypass the fuel pump, keep the fuel filter inline

fill the tank and ride it 50 miles at a time, refilling it so the tank stays mostly full (only down a bit over a gallon). Pretend you have a HD with a peanut tank for a week o_O

If you can put 200 miles on it over a few days with no issues, it was the fuel pump.
 
#51 ·
Brilliant that is my type of diagnosis.............free.
I just had a brainstorm my vtx when it was really hot out with liquid cooling still lost power. Same as i heard with air cooled harley. I would expect our 1100s would do the same. Just another something to store in the back of your brain. (like it isn't full enough)
 
#54 ·
5/16 is correct.
 
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#55 ·
dont bypass the fuel filter

stuff thats small enough to get thru the petcock screen will plug the jets and passages in the carbs
 
#58 ·
Weird. So these two tubes were both connected to the fuel pump. The ends on the fuel pump itself is the same size but look at the hole difference on the tubes. Tube on the left goes from pump to fuel filter. Tube on the right goes to the T connector that is connected to both lines going to carbs.

The T connector looks like 1/4. But the fuel pump ends are both 5/16. It looks like the line from fuel pump to the T connector is 1/4 but stretched like crazy over the fuel pump 5/16....
 

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#59 ·
The lines on my bike were the same thing. Must have come that way. By the way, line on left is not fuel line, well Al least not that will hold any pressure at all. I recommend change to true fuel line.

 
#61 ·
I definitely believe you, I just suggest to replace for longevity and safety purpose.
 
#62 ·
Oh I see..sorry I misunderstood.

So results will be posted shortly. At first I ran the line too long. And when I put the bolts on and the seat it was too much pressure on the line and the bike sputtered and died. Then I shortened the line and the bike is now idling very nicely. Took it for a little ride around my driveway (I have an acre) and so far she's not dying on me. Will take it for an actual ride in about 10 mins so stay tuned.

Here is a picture of the line being too long. See how it wraps around the second bolt for the tank? I shortened it so it now wraps around the first bolt of the tank.
 

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#63 ·
Okay so here's the results. Please keep in mind it's past midnight and I'm exhausted so my ride was short and my mind isn't sharp. But I still noticed one main thing when parking my bike after riding it on the hwy:

-the idle sounded high again. I checked the rpm and it was in spec of 1020rpm. Remember back in the other thread I mentioned that the bikes idle sounded low but it still showed 1020rpm? Well now the sound of the bike actually matches the rpm it's at and doesn't sound quiet at all.

When the bike runs good, I barely have to press the throttle when taking off because the rpm is high so it just wants to go. When the bike runs rough(ish) I have to actually give it some gas when taking off. Tonight, she just wanted to go.

So when the bike would run rough, and even though the idle and timing was correct, it was starving for fuel I'm thinking.

Again, this could all be a fluke, but I haven't heard the idle this high since over a month ago. So that was a nice change.

I will relax a bit and ride the bike a bunch of times so I can see if this really was the fix. Also I want to see how many kms I can ride before it starves for fuel.
 
#64 · (Edited)
OK, I skimmed through this whole thread and have a few comments.

Spark knock from improper plug torque? I LOL'ed at that one. Not gonna happen. Improper heat range, or reach, but not torque.

If you had a big-end bearing issue, it would not come and go randomly - it would come and go based on how much load you placed on the engine. Give her throttle, the noise gets louder. Roll off, it quiets down. That sort of issue doesn't fix itself.

As for the fuel pump - test, don't guess! Check the fuel pressure. Is it within spec? How much fuel will it pump in 30 seconds? Before you condemn the pump, will the wiring light an old sealed beam headlamp, or equivalent load? If that all checks out, your pump is fine. Intermittent lack of engine power is usually an electrical (ignition) problem. Again - test, don't guess! You'll need an adjustable spark tester - progressively widen the gap on it. These bikes should jump well over 1/4" gap without even trying. Anything less, and you need to start digging more.

Just some quick things off the top of my head. Without hearing and seeing the bike, we're all guessing in the dark here.

Just my .02. Graduated from MMI Phoenix 20 years ago, but these days I do more lawn equipment, snowblowers, and cars & trucks.
 
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