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Discussion Starter #1
Bike is suddenly running at lower power. Like at 80%. As if something is causing it to struggle. Two days ago i had to park the bike in the shed before it rained so I started it with choke on, and didnt let it warm up, and rode it/coasted it into the shed and turned it off. I never run the bike until its warmed up but i was in a hurry. The next day i go to start it and the first thing i notice when i started it on full choke is how the bike was much quieter/the bike's rpm wasn't as quick as it normally is on full choke. I put the choke to half and the bike started revving a bit more faster. I put it back to full choke thinking im crazy and the bike bogged down a bit. I took the bike to work and the next thing i notice is that the bike definitely feels off and sounds off, especially in the first gear and a a bit in second gear. Less noticeable in the higher gears.

First thing i though is my carbs were out of sync. So i checked and they were still perfectly in sync. Next I check the rpm using my gauge because of how quiet the bike sounds. (Hard to explain but I'm really in tune with how my bike sounds and feels and since all this started the bike has definitely sounded much quieter than normal). So i check the rpm and its still set at 960 which floors me because i remember when i first set it to 960 how much louder and faster my idle sounded on the bike. Another thing I noticed is how hot the engine feels shortly after starting the bike. I never used to feel any engine warmth on my leg when starting and letting the bike warm up but now suddenly i notice it a lot. I haven't had the chance to take it all apart yet but i wanted to reach out to everyone to collect your thoughts so i can have a list of things to check. At the top of my head here's what I'm thinking:

-Bad gas?
-Air leak? Since putting the choke on full, is causing the bike to bog, so that tells me it's not getting enough air?
-TPS Sensor is off again? Since I just adjusted it last week when I lowered it from over 800 down to spec (700 closed throttle). Maybe the sensor is faulty and is now lower than it should be?
-Carbs are dirty again, even tho i just cleaned them a month or two ago...
-Bad fuel pump or Fuel filter?

Thanks everyone.
 

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need to point out: pull the choke out all the way to start it cold, and as soon as it fires push it in half way.

If you are letting the bike sit and idle with full choke you are fouling the plugs. If your plugs are fouled they wont clear out by themselves

its possible you got water in your gas.

If the bike sounds quieter, is it possible something started building a nest in your exhaust, or some critter crawled in there and died?

You should never have to check the sync on your carbs unless you have taken them apart - the sync adjustments will not shift, wear or change in normal use.
 

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Discussion Starter #4
need to point out: pull the choke out all the way to start it cold, and as soon as it fires push it in half way.

If you are letting the bike sit and idle with full choke you are fouling the plugs. If your plugs are fouled they wont clear out by themselves

its possible you got water in your gas.

If the bike sounds quieter, is it possible something started building a nest in your exhaust, or some critter crawled in there and died?

You should never have to check the sync on your carbs unless you have taken them apart - the sync adjustments will not shift, wear or change in normal use.
Nono i never let it sit on full choke. I only start it on full choke then move it to half. :)

Okay, I'll start with emptying the tank. Once the tank is removed, how to I empty the gas in the lines? Just disconnect each hose from each carb, turn the key on, let it drain, key off, key on, let it drain, etc?
 

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are you draining the tank to change to regular gas
or because you think there could be water in the gas?

if its water, take the line off the petcock, drain the tank, and fill it with good gas an some Seafoam

thats all you need to do - any drips of water still in the tank will be absorbs by the seafoam and burned off gradually - also any water in the fuel lines will get flushed out by the seafoam mixed in the gas

its 1 ounce per gallon - some people dump the whole 16 ounce bottle in a 5 gallon tank - dont do that.

If you are only changing octane ratings just drain the tank from the petcock and fill it with regular, dont worry about the little bit of gas in the lines and float bowls

I calculated once the two tablespoons in each float bowl is enough to get the bike about a mile down the road, and I verified that a few times when I forgot to turn the petcock on.
 

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Turn off petcock. Pull line off fuel pump from tank, put in empty gas can, turn petcock to reserve, fix glass of sweet tea (it's a southern thing), drink tea, watch can fill up. Put gas in your car. Buy some new gas. Put in tank. You will still have some fuel in carb bowls so might take riding a few miles to get it all burned. Before you put gas in car, look at it. Any moisture floating around? If so don't put in car.
 

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KCW, you type too fast. 😂
 

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Turn off petcock. Pull line off fuel pump from tank, put in empty gas can, turn petcock to reserve, fix glass of sweet tea (it's a southern thing), drink tea, watch can fill up. Put gas in your car. Buy some new gas. Put in tank. You will still have some fuel in carb bowls so might take riding a few miles to get it all burned. Before you put gas in car, look at it. Any moisture floating around? If so don't put in car.
It must be a southern thing up here we spell sweet tea BEER
 

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Discussion Starter #9
are you draining the tank to change to regular gas
or because you think there could be water in the gas?

if its water, take the line off the petcock, drain the tank, and fill it with good gas an some Seafoam

thats all you need to do - any drips of water still in the tank will be absorbs by the seafoam and burned off gradually - also any water in the fuel lines will get flushed out by the seafoam mixed in the gas

its 1 ounce per gallon - some people dump the whole 16 ounce bottle in a 5 gallon tank - dont do that.

If you are only changing octane ratings just drain the tank from the petcock and fill it with regular, dont worry about the little bit of gas in the lines and float bowls

I calculated once the two tablespoons in each float bowl is enough to get the bike about a mile down the road, and I verified that a few times when I forgot to turn the petcock on.

This issue started while i was running regular gas but I was down to 40 km left on the tank so I threw in premium gas and seafoam thinking it would improve things. My bad lol. So I'll be draining out premium gas and replacing it with regular.

Here's the kicker: My friend parked her bike in my driveway and left it there because her bike started running like garbage after she filled up on gas. 3 days later and the same thing happened to my bike. Quite the coincidence.

Also a sidenote: A couple of nights before, I rode with some buddies. They ride fast and I was keeping up, going the bikes limit, which on my bike is 160 - 170km/hr. The bike rode fine the next day so I don't think whatever is the issue is from that night but still worth mentioning.
 

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if the bike was acting up on regular gas then the premium is not the issue, unless it has gotten worse

seafoam will help if there was water in the gas, but it wont help if the fuel is got goop in it, sludge, or was contaminated with something else (like diesel fuel in the underground tank)


If the engine is just a bit off, other than checking your plugs, look at your air filter - it doesnt take much dust in there to choke the engine, or you could have a bunch of bugs or something sucked in.
 

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Discussion Starter #11
Ooooh sheet. Look what I found. My plugs are normally super clean. Both plugs oil fouled so im guessing it's not getting enough air? I can throw in my old K&N air filter for testing purposes to see if my oem paper filter is clogged (it's only 2 months old)
 

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Discussion Starter #12
Can I clean these off with a wire brush or should I buy new ones. These ones are two months old and they were super clean a few weeks ago. So maybe the 170km/hr drive I had wasn't good on the bike?
 

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the filter is easy to check, if its not white like paper chuck it. Make sure nothing else is infront of the filter restricting it

did you have the K&N filter on this bike, and switched back to the stock one for some reason? If so did you re-jet the carbs going one way or the other? If the jets were changed for the K&N filter it will be rich with the stock filter on the bike.

Also need to make sure the choke cable and moving parts are all working, and the choke is not partly staying on when you think its in all the way.

plugs are cheap, cleaning dirty plugs is not easy, and sometimes risky that you will get crud in the combustion chamber (pieces of wire from the brush, sand from sand paper or sand blasting...)

you also said the bike sounds quieter - a restricted exhaust will make the bike run rich, because it cannot push out the same amount of exhaust gas, so it cant pull in the normal amount of fresh air on the intake stroke, and the fuel will not all burn correctly. If the bike has the OEM exhaust maybe the catalytic converter has collapsed and is blocking the flow.

where did you get to run the bike at 105mph, and how far did you ride at that speed?
 

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Plugs are cheap, get new ones. KCW is correct on the jetting. If jetting wasn't changed just put new plugs in and should be good. Possible after a somewhat long high speed run and sudden throttle closure you flooded the bike for a second and plugs became fouled. It's hard to "burn" off a fouled plug. The fouling of plugs is common on race vehicles, that's why I always carry several sets of plugs when I go to the track.
 

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Discussion Starter #15
the filter is easy to check, if its not white like paper chuck it. Make sure nothing else is infront of the filter restricting it

did you have the K&N filter on this bike, and switched back to the stock one for some reason? If so did you re-jet the carbs going one way or the other? If the jets were changed for the K&N filter it will be rich with the stock filter on the bike.

Also need to make sure the choke cable and moving parts are all working, and the choke is not partly staying on when you think its in all the way.

plugs are cheap, cleaning dirty plugs is not easy, and sometimes risky that you will get crud in the combustion chamber (pieces of wire from the brush, sand from sand paper or sand blasting...)

you also said the bike sounds quieter - a restricted exhaust will make the bike run rich, because it cannot push out the same amount of exhaust gas, so it cant pull in the normal amount of fresh air on the intake stroke, and the fuel will not all burn correctly. If the bike has the OEM exhaust maybe the catalytic converter has collapsed and is blocking the flow.

where did you get to run the bike at 105mph, and how far did you ride at that speed?
It had the K&N filter in it when I bought it. I put a new stock filter in it to correct the fuel/air mixture. I looked at my stock filter just now and there's dead bees in there. How the hell did they get INSIDE the filter... That doesn't make sense...

Jets are all stock. Air fuel mixture screws are untouched. Everything is bone stock on this bike.

Choke cable was good last time I checked it out but will check again in a bit when I head back to the shed to work on it some more.

There is no catalytic converter on this bike. Those started on the 2004 models I believe. I'll be removing the exhaust and checking the inside to ensure nothing broke loose or nested in there.

There's a highway not far from my house. It was me and 7 Yamaha r6s and r1s lol. They like to get a little crazy and I was trying to keep up so I was going 170, maxed out, for about 20 mins or so.
 

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Discussion Starter #16
So I changed the air filter to the K&N, changed the plugs, and changed the gas. Bike seems to be running better than it did but I'll know tomorrow when I go to cold start it . If it still bogs down on full choke when I first start it, I'll know something still isn't right. Bike is currently draining oil, since she deserves an early oil change for me riding her rough lately.

Just out of curiosity, in case this happens, what would be the reasons on a bone stock bike running rich, asides from a clogged air filter?
 

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from everything you posted the dead bees inside the air filter are the likely problem

are you sure the air filter works in the direction you think, the air comes in from the circumference and gets pulled into the engine from the center for example, or the other way around?

if bees are behind the filter then either the air box is popped up loose from the top of the carbs
or the engine breather hose from the rear cylinder head has come off and bees got in there
or they chewed a hole thru the air filter
or maybe even they flew into the exhaust, started building a nest in there? no.. that cant be it, the bike might be parked with one intake or exhaust valve left open but I dont see how bees could get from the exhaust thru an open exhaust valve, and then find their way into the carbs - the intake and exhaust valves would have to be both open - not possible

I would take the tank off and pull the entire air box off, checking to see if it was not fully connected anywhere
and look inside it for more bees.

If there was a lot of them in the air box, when you started the bike they could have gotten sucked into the cylinders, and then blow out into the exhaust.

the only amusing thing about this, if it is the cause of your bike not running right, its called: Creature Damage
 

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I'm surprised to hear that premium gas could be an issue.

Where I live premium gas is the only grade that has zero ethenol so everyone here always fills their tank with premium if they won't be riding much / for winter storage regardless if it's a dirt bike, scooter, adventure or cruiser. I've never had an issue (multiple bikes) nor have I heard of anyone in our MC having an issue with premium. Premium will leave extra carbon deposits on a lower rpm (non high performance) engine but my experience (including on my VStar) is the bike does not run any differently.
 

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Discussion Starter #20
from everything you posted the dead bees inside the air filter are the likely problem

are you sure the air filter works in the direction you think, the air comes in from the circumference and gets pulled into the engine from the center for example, or the other way around?

if bees are behind the filter then either the air box is popped up loose from the top of the carbs
or the engine breather hose from the rear cylinder head has come off and bees got in there
or they chewed a hole thru the air filter
or maybe even they flew into the exhaust, started building a nest in there? no.. that cant be it, the bike might be parked with one intake or exhaust valve left open but I dont see how bees could get from the exhaust thru an open exhaust valve, and then find their way into the carbs - the intake and exhaust valves would have to be both open - not possible

I would take the tank off and pull the entire air box off, checking to see if it was not fully connected anywhere
and look inside it for more bees.

If there was a lot of them in the air box, when you started the bike they could have gotten sucked into the cylinders, and then blow out into the exhaust.

the only amusing thing about this, if it is the cause of your bike not running right, its called: Creature Damage
My educated guess is that when I was troubleshooting my bike running like crap after I cleaned my carbs, I tested it once I fixed it and rode it up and down my driveway about an acre without my air filter on so maybe it sucked up the bee and fly that I saw. Weird that it pushed them out though. And yes I understand how the air intake works lol. Air gets sucked from the outside into the air filter housing, through the air filter, into the airbox, then through the carbs, receiving a mixture of fuel along the way to the cylinders, which is why I was confused on how the bugs got inside the filter hahah. Ah well. Fingers crossed for tomorrow morning!

Thanks for the help today everyone. I'll post an update tomorrow.
 
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