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Post by jjoshua20213 on Jul 29, 2013 5:38:09 GMT -5
I have a spare carb with an  jet. Could never get it to run right on any of my bikes, and now I need it. When its on it revs then when in mid range it "spudders" and cuts out and won't reach top rpm. The carb was new when I got it, what could be wrong? |
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Post by jerseyboy on Jul 29, 2013 8:31:06 GMT -5
Any mods done to scoot?
Make sure the pilot and main jet are clean and tight,check the slide needle and diaphram make sure they are put together correct....mid to top end is mostly coming off slide needle and main jet.
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Post by jjoshua20213 on Jul 29, 2013 11:58:06 GMT -5
50mm bbk
Everything is clean and assembled. I tried moving the spacer in the needle to the highest setting.
Stock carb works fine but was already too lean with stock cylinder and is epa so I cant open it. I don't wanna buy another one and have the same problem
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Post by jjoshua20213 on Jul 29, 2013 11:59:40 GMT -5
Also tried putting in another new jet and 40idle. The idle was too rich so i put in stock |
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Post by brandjur on Jul 29, 2013 12:12:05 GMT -5
Is it just the bbk or do you have an intake or exhaust as well? For those who have done 50mm bbk's, they usually use a higher main jet than # . You might need a #  -#92 if all you have is the bbk. To richen the mixture, you need to move the clip to the lowest setting, so the needle actually sits higher. 40 pilot jet is too big, good hting you changed it back. Also, have you checked the spark plug? So we can better help you and get a clearer picture, please list your mods, how it behaved before the bbk, and other history while doing the bbk. |
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Post by jjoshua20213 on Jul 29, 2013 18:06:20 GMT -5
Its just the bbk. Prior to the bbk I put in 4gram slider to mix in with the stock rollers. Gave it better accel and top. I was using stock carb and air filter. It was running too lean stock and the engine was over heating. Noticed the exhaust valve on the stock head getting burned. The plug always read lean and a new plug would get burned in two days because of its leaness. Still ran the same though. I know that stock 49cc carb jet is not . was recommended on my last bbk and came with this one. The scooter now runs extreamly lean with stock carb and filter. I tried free flow filter with the second carb with no results. Before the bbk this carb would make the bike run slower so i took it off before getting to my destination. Never got the change to pull the plug while using it. At low rpm its fine, but as soon as the trottle gets to around 1/4 its starts spuddering and cutting out. The carb is not old enough and has not been used enough to get dirty, but I cleaned it anyway. Scooter always starts easy. The scouter sounds like my other bike did when one of the wires to the ignition coil was loose. Like its misfiring or bad timing which I know isn't the case because I marked a link on the cam chain before removing it, so when I put it back I would know. Stock carb works even though its really lean. New carb has bigger jet and runs like crap but I can tell its running richer and better before it starts acting up. I was thinking the foat was running out, but the engine never dies. just instantly acts up at the same point weather I open it up fast or slow. |
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Post by jjoshua20213 on Jul 29, 2013 18:40:25 GMT -5
Also, will running the stock carb with auto-enricher unplugged help its leaness? Or cause another problem? I think all it does is close an extra gas passage when plugged it, and doesn't restrict air flow.
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Post by ltdhpp on Jul 29, 2013 18:51:02 GMT -5
You need a larger jet for a BBK... an is for bolt ons. Its not going to run right with any carb until you get the right jet in it. |
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Post by jjoshua20213 on Jul 29, 2013 19:30:09 GMT -5
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Post by newbscootdude on Jul 29, 2013 20:44:46 GMT -5
jjoshua
im not being rude or anything but these guys know what theyre talking about and chances are who ever recommened that has no idea what theyre talking about.
so to me you have two choices
1) listen to these guys and have a proper running scooter
2) not listen to them and have your scooter run lean and blow your enegine
its up to you!
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Post by jjoshua20213 on Jul 29, 2013 21:29:10 GMT -5
I just unplugged the auto enricher and moved the washer on the carb needle to the lowest setting. The bike had to have been too rich because it started going slower and somewhat spuddering like the other carb when in low/mid throttle , but when in wot (Mainjet) it kinda evens out and when I let off the throttle its the same spudering. So I raised the needle two notches and it gets better. So I raised it to the second to first line and it runs almost normal with great acceleration then around top speed it crawls to a higher speed as if its still really rich. I put on a free flow now it runs excellent, and still crawl to higher speeds like the exhaust is restricting combustion.
My guess is that the other carb was too rich for the rate of combustion being allowed by the stock exhaust. The stock carb was too lean so unplugging it allows more gas to be added to the mixture thus somewhat evening things out.
This would explain why the other carb started working better on the other bike when it got a bad exhaust leak.
After all this testing the plug looked like it was extremely rich at one point in time then normal.
My funds just got low and i'm trying to work with what I got. I thought the other carb would work so I didn't get one when I got the kit or an exhaust. So until next check I don't wanna ruin the new build running lean..
Any thoughts on the settup?
Also how much gas is allowed to flow through the enricher?
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Post by geh3333 on Jul 30, 2013 3:43:27 GMT -5
some future advice , if your runnig as lean as you were saying , burning vavlves and whatnot . do not run a lean scoot thats even close to overheating . it sounds as of you already did some damage . hope everything works out .
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Post by jjoshua20213 on Jul 30, 2013 11:42:41 GMT -5
some future advice , if your runnig as lean as you were saying , burning vavlves and whatnot . do not run a lean scoot thats even close to overheating . it sounds as of you already did some damage . hope everything works out . Forgot to mention that the bbk has less than one mile on it. I noticed the old part was getting a little burned when I was switching it out. With the current setup listed above it should be fine. I've been trying to get it tuned before I took it out for its first ride. |
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Post by ltdhpp on Jul 30, 2013 11:53:13 GMT -5
Wait, you are running a BBK with stock exhaust??? Stock exhaust is restrictive to a stock motor...
I'm not experienced with BBK's but I'd guess they don't play well with stock exhaust.
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jet. Could never get it to run right on any of my bikes, and now I need it. When its on it revs then when in mid range it "spudders" and cuts out and won't reach top rpm. The carb was new when I got it, what could be wrong?
-#92 if all you have is the bbk. To richen the mixture, you need to move the clip to the lowest setting, so the needle actually sits higher. 40 pilot jet is too big, good hting you changed it back.
MJ, Orange coil, Blue Performance CDI (Orange NCY did not work), NGK Iridium, 5g Sliders
(need 112)
