I'm having problems with throttle repsonse on my bike above about half throttle. When I bought the bike airbox was missing so i put some foam filters on it. Checked a website called carbjetkits.com and they said I'd need 130 main jets, 45 pilots, and 2 shims per needle. Installed them, rebuilt the carbs. Above half throttle in all gears bike sputters pops and won't accelerate. Went back to the stock 120 jets and removed a shim from each needle leaving one per needle. Problem was still there, so i sprayed the filters with K&N filter oil didn't help. What else should I do?
84 vt700 carb help
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Are you running stock pipes?
Also going back to stock 120 mains will never help your issue. You went backwards and choked the fuel down again. You have A LOT of air going into the motor right now.
Pod filters are hard to tune for. If your running stock pipes your never gonna get that thing running right with pod filters.
Pod filters should only be used on a full staged 1 bike. So either buy a used air box or open the pipes up. Even if you just run the header pipes, i bet it will run better with the full jet kit installed than it is now.
Also set your a/f screws at about 2.25 turns out and adjust it from there. thats with the full jet kit and mufflers off.
Its also possible the the airfilters your running are to big. I think 36mm pods is all you need. Your pic won't load for me. I have a weak wifi connection right now. I can't see how big the filters are.
Also going back to stock 120 mains will never help your issue. You went backwards and choked the fuel down again. You have A LOT of air going into the motor right now.
Pod filters are hard to tune for. If your running stock pipes your never gonna get that thing running right with pod filters.
Pod filters should only be used on a full staged 1 bike. So either buy a used air box or open the pipes up. Even if you just run the header pipes, i bet it will run better with the full jet kit installed than it is now.
Also set your a/f screws at about 2.25 turns out and adjust it from there. thats with the full jet kit and mufflers off.
Its also possible the the airfilters your running are to big. I think 36mm pods is all you need. Your pic won't load for me. I have a weak wifi connection right now. I can't see how big the filters are.
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Ok. I got your pic to load.
Dude..lol those filters are WAAAAAAAY to big. That thing is never gonna fully run. I know my 500 calls for 36mm pods. I'm almost 100% sure that yours does too. So measure the carb mouths and covert it to mm. It should be 36mm. I think our carbs are the same but i'm not sure.
Dude..lol those filters are WAAAAAAAY to big. That thing is never gonna fully run. I know my 500 calls for 36mm pods. I'm almost 100% sure that yours does too. So measure the carb mouths and covert it to mm. It should be 36mm. I think our carbs are the same but i'm not sure.
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this is the process I use to tune ... worked well for me on my 1100
http://www.factorypro.com/tech/tech_tuning_procedures/tuning_carbtune,CV,lower_rpm_engines.html
I did end up going way bigger on mains with my airbox opened up and dropped the needle down (had a dyno adjustable needle)
the other thing is make sure your plugs are good as fouled plugs will make it hard to test how it runs throughout the rev range.
http://www.factorypro.com/tech/tech_tuning_procedures/tuning_carbtune,CV,lower_rpm_engines.html
I did end up going way bigger on mains with my airbox opened up and dropped the needle down (had a dyno adjustable needle)
the other thing is make sure your plugs are good as fouled plugs will make it hard to test how it runs throughout the rev range.
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where the black sutty lookin? or nice and white in the middle?
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Thanks for the props man. I have it up for sale, but If it doesn't sell, i'm gonna keep it and finish it. With that comes my plans for an airbox delete and pods too.
My pipes are the stockers but with 14" extensions and lolliepop baffles that I made.
So if your pipes are cobras or something other than stock you should be ok. You just need smaller pods. Reinstall the FULL jet kit. Set your a/f screws at 2.25 turns out each.
The best way to tune, if you can get ahold of one; is a laser temp gun. Its what I used to dial in my head pipe temps, at the heads. Between that and my a/f setting i was down to 1-3 pops on decel and not all the time. My plugs were beige/gray. So I got it pretty close. But that was with me just tunning for my pipe modification.
The same process should work for your application too. Adjust your a/f at 1/2 turn increments and grab the throttle. I think at around 2.75 turns out, you will only have 1-3 pops on decel.
The real issue is gonna be tuning for the mid to upper rpms. I would definately plan on syncing the carbs to help dial in the upper rpms if you have problems with a basic tune.
I'm currious how this pans out.
My pipes are the stockers but with 14" extensions and lolliepop baffles that I made.
So if your pipes are cobras or something other than stock you should be ok. You just need smaller pods. Reinstall the FULL jet kit. Set your a/f screws at 2.25 turns out each.
The best way to tune, if you can get ahold of one; is a laser temp gun. Its what I used to dial in my head pipe temps, at the heads. Between that and my a/f setting i was down to 1-3 pops on decel and not all the time. My plugs were beige/gray. So I got it pretty close. But that was with me just tunning for my pipe modification.
The same process should work for your application too. Adjust your a/f at 1/2 turn increments and grab the throttle. I think at around 2.75 turns out, you will only have 1-3 pops on decel.
The real issue is gonna be tuning for the mid to upper rpms. I would definately plan on syncing the carbs to help dial in the upper rpms if you have problems with a basic tune.
I'm currious how this pans out.
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the top plugs are from one pot the bottom two from the other, the rear cylinder is slightly rich at low revs, the front (lower set) richer again at low Revs but sweet up higher
This was after a small stint at higher revs after a stretch at low so it burnt off some of the soot when at high but it still shows rich
you can see the RH lower plug only has a touch of white while the upper RH has more but still a little blackish
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Syncing is not hard. There are videos on it.
Leathel. with yours....might I make a testing suggestion..??
Clean your plugs up like new. take it out for a 20 min ride just cruising and shifting at your cruising stlye rpms. Take them out and snaps some pics.
Then clean them again and run her somewhat hard, again for 20 min. Then pics again.
I say this because it looks like to me the rear cyl is a tad bit lean and maybe could use a 1/4-1/2 turn out. If you run the bike as I suggested maybe the plugs will look different.
Or is it me....lol What do you think buddy..?
Leathel. with yours....might I make a testing suggestion..??
Clean your plugs up like new. take it out for a 20 min ride just cruising and shifting at your cruising stlye rpms. Take them out and snaps some pics.
Then clean them again and run her somewhat hard, again for 20 min. Then pics again.
I say this because it looks like to me the rear cyl is a tad bit lean and maybe could use a 1/4-1/2 turn out. If you run the bike as I suggested maybe the plugs will look different.
Or is it me....lol What do you think buddy..?
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Or you could buy it and have a real life template...:mrgreen:
Post some pics of it and let me know if you have any ?'s
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if your carbs are blacker than that they will be fouling and have erratic spark causing it to pop and miss with load
3 main causes that I can see
Jets too big
Float level to high (or crap in the float valves causing it to get high)
too much fuel pressure causing the float valves to leak ( same effect as float level high)
I had issues with the last listed problem for a while
syncing will not make it run leaner
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For the record..lol I never said that syncing will make it run leaner, allthough it does look like i was illudeing to that now that I read it again...lol. So i will explain what I meant by that.
Imo, If someone is having a hard time getting the bike to run right after a pod mod and an agressive rejet, I would sync the carbs because with that much air and fuel being dumped into the carbs the last thing you wanna chase is a lazy opening throttle plate. I meant it more of a dial in then a help/solution for a lean condition. Which it most certainly does not solve.
So I appologize for that guys. With that said, Leathel is absolutly correct. And to add to that, if you were that rich as Leathel decribed you would have gas comming out of the pipes and/or your plugs would be soaked in fuel.
I'm stayin with my first prognossis becuase if it didn't come with an airbox and your jetting it with those oversized airfilters, it will most definately act like it is.
But AGAIN, Leathel makes a good point. If the airbox was missing, who's to say that the P/O wasn't chasing down a fuel issue. So maybe its as Leathel says and you have float, needle valve issues too.
Its really hard to fixshit on the internet..lol.
Imo, If someone is having a hard time getting the bike to run right after a pod mod and an agressive rejet, I would sync the carbs because with that much air and fuel being dumped into the carbs the last thing you wanna chase is a lazy opening throttle plate. I meant it more of a dial in then a help/solution for a lean condition. Which it most certainly does not solve.
So I appologize for that guys. With that said, Leathel is absolutly correct. And to add to that, if you were that rich as Leathel decribed you would have gas comming out of the pipes and/or your plugs would be soaked in fuel.
I'm stayin with my first prognossis becuase if it didn't come with an airbox and your jetting it with those oversized airfilters, it will most definately act like it is.
But AGAIN, Leathel makes a good point. If the airbox was missing, who's to say that the P/O wasn't chasing down a fuel issue. So maybe its as Leathel says and you have float, needle valve issues too.
Its really hard to fixshit on the internet..lol.
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