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Post by lain on Mar 13, 2015 15:07:05 GMT -5
So the other day I tweaked my carb because I thought it could have been a mix issue. It went away after I tweaked the carb but I am starting to think it may have been a coincidence. The starting issue came back the same day and went away again a few times. Then today it is having issues idling at 1800, sounds like it misfires randomly or hiccups sort of if you know what I mean.
Then when I got on the road today I felt something new happen. at random it felt like the acceleration curve was being cut in the mid and high range. The engine also makes a different sound in this range. When I am going about 20 and I try to rev up past half throttle it feels like it slows down a lil bit until I back off the throttle. Then I try again the same thing and it will go faster or do the same thing again with no other changes to what I'm doing. When I am already up to about 30-40 if I go more than half it will go faster but you can hear the engine noise change sort of sounding smoother and less noise but the speed does not change much unless you let it take some time.
Then if I get up to the higher speeds and suddenly drop the throttle I can smell something like rubber burning, or maybe gas, I'm not sure exactly but there is no smoke or anything.
When I try to start it will start fine sometimes, usually the first time of the day it will be fine, but other times it will not start fine. It starts up if I twist the throttle a little when it is giving me issues starting. It seems to come and go, sometimes I can just press the start button and it will fire right up in a second or less, sometimes it will sound like it is turning and firing either late or maybe sporadically or maybe barely at all. I really need to check to see what the spark looks like at night but the end looks fine so that is good at least.
It's 40 degrees today, the other day it was 50, I couldn't possibly have to change my carb tuneup with every 10 degrees of temp change could I?
I'm seriously suspecting somethign electrical could be the issue, I am going to try using another CDI. I have already checked the connections on the coil and wire, the plug is light brown colored which I believe to be good. The coil I am using is very old, and was a stock part from a scooter I salvaged the coil from which had been sitting outside for a couple years.
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Post by geh3333 on Mar 13, 2015 16:09:28 GMT -5
So the other day I tweaked my carb because I thought it could have been a mix issue. It went away after I tweaked the carb but I am starting to think it may have been a coincidence. The starting issue came back the same day and went away again a few times. Then today it is having issues idling at 1800, sounds like it misfires randomly or hiccups sort of if you know what I mean. Then when I got on the road today I felt something new happen. at random it felt like the acceleration curve was being cut in the mid and high range. The engine also makes a different sound in this range. When I am going about 20 and I try to rev up past half throttle it feels like it slows down a lil bit until I back off the throttle. Then I try again the same thing and it will go faster or do the same thing again with no other changes to what I'm doing. When I am already up to about 30-40 if I go more than half it will go faster but you can hear the engine noise change sort of sounding smoother and less noise but the speed does not change much unless you let it take some time. Then if I get up to the higher speeds and suddenly drop the throttle I can smell something like rubber burning, or maybe gas, I'm not sure exactly but there is no smoke or anything. When I try to start it will start fine sometimes, usually the first time of the day it will be fine, but other times it will not start fine. It starts up if I twist the throttle a little when it is giving me issues starting. It seems to come and go, sometimes I can just press the start button and it will fire right up in a second or less, sometimes it will sound like it is turning and firing either late or maybe sporadically or maybe barely at all. I really need to check to see what the spark looks like at night but the end looks fine so that is good at least. It's 40 degrees today, the other day it was 50, I couldn't possibly have to change my carb tuneup with every 10 degrees of temp change could I? I'm seriously suspecting somethign electrical could be the issue, I am going to try using another CDI. I have already checked the connections on the coil and wire, the plug is light brown colored which I believe to be good. The coil I am using is very old, and was a stock part from a scooter I salvaged the coil from which had been sitting outside for a couple years. Did you buy a new carb ? Can you remind me what kind of work u have do with the carb ?,thanks. |
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Post by geh3333 on Mar 13, 2015 16:17:40 GMT -5
When I first got my scoot , I had trouble with my carb . acceleration issues , bogging , and other symptoms. I inspected , cleaned and adjusted it to no avail. Bought a new stock carb and the scoot ran perfect. I've heard this a number of times over the yrs , that is having to buy a new carb then everything was ok . I have a 24mm keihin carb , it may be a knock off but its a nice carb. I would give it to you , but I know u have a 50cc . TBA it would probably work but that's up to you . if you already tried a new carb , then ignore my post , lol
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Post by lain on Mar 13, 2015 16:23:42 GMT -5
I got a keihin carb a while ago and wasn't having any issues with the tune till this week. It hit up to 50 degrees and I had to retune the carb from rich to lean, and today it is 40. I don't think 10 degrees would make a big difference, I was running excellent when it was 50, but still had starting issues and had to rev to start it. Today the starting issue is the same, it comes and goes and revving a lil bit seems to bring it to life while it is having issues starting. I was talking about the tune in this thread earlier in the week: itistheride.boards.net/thread/7395/tachometer-hard-starting-bad-idle?page=4&scrollTo=88101 |
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Post by lain on Mar 13, 2015 16:27:30 GMT -5
I am more concerned about the sudden cutting of the power at higher throttle when at slower speeds. I mean could it just be that I need a different main jet for my tune? Before it didn't seem to cut the power down but it would not give much more power over 70% throttle. Now it seems to be cutting the power of the engine down at 70%+ throttle. It feels liek whenever I get that high unless I'm already going 30+ it cuts the power down, however if I AM going 30+ it seems to give a little but not much more power.
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Post by lain on Mar 13, 2015 16:28:34 GMT -5
Oh and when I go uphill it also seems to feel like the power is cutting down even at lower throttle.
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Post by geh3333 on Mar 13, 2015 16:49:21 GMT -5
I agree , when u adjusted the carb it was very cold , and will def need to be adjusted again somewhere after 35degrees . I would not expect you would have to adjust for every 10 degrees, unless the last time you adjusted the air fuel it was just enough so it seemed to run right. In this case I guess it may be possible after a 10 degree increase you may need to do some more adjusting . I would say normally every 20 degrees may effect these small one cylinder engines . but TBa between 60 and  + I never noticed any real difference but once it drops to 50 I have to adjust , then 30degrees another adjustment and then 10 would be my next adjustment For example , I was riding in 20 degree weather most of the winter , but when it warmed to 40 I had to adjust the air fuel . mine I a 150 and I would imagine the smaller 50cc may need sooner adjustments. |
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Post by lain on Mar 15, 2015 11:16:31 GMT -5
So now it is the same as it was before I started trying to tune the carb to solve the problem. It is 30 degrees, the mix has been set back to where it was from before I started having issues, same with the needle. So since I am now using the same setup as it was when it was last working great I have to think the problem is NOT the mix...
Having all the issues I had above, the starting issue still coming and going, the carb is now set at the last known great workin conditions. Now it is having issues idling at 1800, I have to bring it up to about 2100 to have it idle smooth. It still seems liek it is misfiring randomly, every now and then, but no pattern for it so far that I have noticed.
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Post by JoeyBee on Mar 15, 2015 11:30:47 GMT -5
This fluctuations in temps has been pissing me off too. I've given up on continuously adjusting me carb until it is consistently holding above 60 degrees outside.
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Post by tvnacman on Mar 15, 2015 13:33:36 GMT -5
Did you check the valve lash before adjusting the a/f? If you say no I would see if the lash is off . My gut tells me is electrical. Being that your questioning the coil perhaps change it for good measure.
John
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Post by lain on Mar 15, 2015 13:37:45 GMT -5
Did you check the valve lash before adjusting the a/f? If you say no I would see if the lash is off . My gut tells me is electrical. Being that your questioning the coil perhaps change it for good measure. John Yeah, I had them tuned to 0.005, they were still there. I'm planning on buying one of those Casoli CDIs and a new coil as soon as I have money, unfortunately I won't have money for a couple weeks. I'm about to just try one of my advanced angle CDIs, I know it will have issues starting because it gives me kickback sometimes but I am more interested in seeing if the low end and top end is better with a different CDI and it's the only other one I got. I am actually getting ready to go out and do that and go for a ride. |
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Post by tvnacman on Mar 15, 2015 14:41:07 GMT -5
I have seen coils act real funny.
John
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Post by lain on Mar 15, 2015 15:29:24 GMT -5
I have seen coils act real funny. John Yeah, my next move is a coil but I don't have another one right now. I tried to use the blue advanced angle CDI that I have, and as expected it was a lot of effort to start, but unlike the last time I used it this time the idle was sporadic and was up to about 3000-3200 and having issues staying alive then after about 30 seconds of idling it died and would not start again. So then I popped in the old OEM stock CDI and it started up after a couple tries and idled smooth at 2100. Then I went for a ride and it ran smooth, but was still having issues in the high end as before, but a little less of a problem. The funny thing is its raining out here and it started up just fine when I was leaving the store. Still unsettling how it comes and goes. I swear, my scoot just loves crappy weather, always runs nice in it lol. |
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Post by lain on Mar 16, 2015 12:10:08 GMT -5
I agree , when u adjusted the carb it was very cold , and will def need to be adjusted again somewhere after 35degrees . I would not expect you would have to adjust for every 10 degrees, unless the last time you adjusted the air fuel it was just enough so it seemed to run right. In this case I guess it may be possible after a 10 degree increase you may need to do some more adjusting . I would say normally every 20 degrees may effect these small one cylinder engines . but TBa between 60 and + I never noticed any real difference but once it drops to 50 I have to adjust , then 30degrees another adjustment and then 10 would be my next adjustment For example , I was riding in 20 degree weather most of the winter , but when it warmed to 40 I had to adjust the air fuel . mine I a 150 and I would imagine the smaller 50cc may need sooner adjustments. How much tweaking do you usually do when you tune for above 30 then for above 50 degrees? Just the mixture screw or do you find yourself changing things like the jet sizes and the needle position? |
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Post by JerryScript on Mar 16, 2015 13:04:48 GMT -5
You should only need to turn the a/f screw when adjusting for temp changes, and not more than 1 1/2 turns.
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+ I never noticed any real difference but once it drops to 50 I have to adjust , then 30degrees another adjustment and then 10 would be my next adjustment 
