|
|
Post by Doug in San Diego on Dec 17, 2009 17:45:59 GMT -5
Hello Dawgs
I was tinkering on my scooter. It was warmed up. I thought I would check the Air mixture screw.
I turned it all the way closed and there was no difference. I turned it out 2 turns and left it. There was no change at all at any time.
In the past, the idle would change as I adjusted the screw.
Is this a sign of anything? It runs fine, but I thought this was weird.
Thoughts?
|
|
|
|
Post by JR on Dec 17, 2009 17:54:43 GMT -5
Hmmmm sounds like you've got a broken adusting screw or something plugged up??
Now when you say closed you did mean all the way in turning it clock wise untill it stopped? JRR
|
|
|
|
Post by als01seville on Dec 17, 2009 18:09:09 GMT -5
Was the engine cold or hot? If was cold the enricher would be open and letting plenty of fuel in so moving the air/fuel mixture at that time would have no effect. You could have also turned it in TO HARD and broke the needle. So take it out and see if it is broke.
Alleyoop
|
|
|
|
Post by speedracer12 on Dec 17, 2009 20:19:10 GMT -5
I must have the same problem as I can turn my idle mixture in and out with no effect on idle speed. What does trouble me the short drop off of power at 3-4 thousand RPM's. Can't get rid of that stutter. Lean or Rich nothing changes.
|
|
|
|
Post by 09speed3 on Dec 17, 2009 20:53:45 GMT -5
I'm guessing we are all going through the same thing. Uping the slow jet might help not sure. Look at your plug
|
|
|
|
Post by Florida Chameleon on Dec 17, 2009 21:31:02 GMT -5
i am having the same no-adjust with the air mix screw...
|
|
|
|
Post by rockynv on Dec 17, 2009 23:33:44 GMT -5
The air mixture port activates based on the proximity of the throttle plate to the port. If adjusting it does not have any effect then the port is either plugged or the entire carb is so out of adjustment that the throttle plate is not returning to the correct position to activate the port. This can happen when the idle is set too high due to other issues such as enrichner not working correctly or valves in need of adjustment.
|
|
|
|
Post by Doug in San Diego on Dec 17, 2009 23:44:43 GMT -5
Throttle Plate??
That's a new one to me. Can you explain what you mean?
I have a38 and 122 jets with a UNI and "Performance" exhaust.
My plug is a nice color, not black, but not white.
What is a throttle plate?
Doug
|
|
|
|
Post by als01seville on Dec 18, 2009 0:00:02 GMT -5
Throttle Plate is just what it says, its a flat plate that opens or closes the intake part of your carb. Your Throttle cable is what controls that, it has to be a little open to idle and thats what your IDLE SPEED SCREW the one that has the spring on it controls. If you turn in the IDLE SPEED screw ALL its doing is opening the PLATE a little if you turn out the IDLE SPEED screw it lets the PLATE to close more and less gas goes in.
Are you idleing to high? you should be around 1500rpm at idle.
Alleyoop
|
|
|
|
Post by als01seville on Dec 18, 2009 0:12:34 GMT -5
your Slow Jet effects it from around 1/4 to 1/2 throttle, it has very tiny holes so it could be clogged.
Alleyoop
|
|
|
|
Post by Doug in San Diego on Dec 18, 2009 0:13:26 GMT -5
I could be too high , but I don't have a tach, so I can't tell the exact rpms
If I lower the idle RPMs, this will allow the idle air mixture to have an effect?
|
|
|
|
Post by als01seville on Dec 18, 2009 0:24:51 GMT -5
It should effect it one way or the other. UNLESS your enricher is NOT WORKING and its feeding it fuel even when its warm, which would also cause you to run rich at mid range and possibley all the way to Wide Open Throttle.
Alleyoop
|
|
|
|
Post by WildMan on Dec 18, 2009 0:48:53 GMT -5
Doug in San Diego
Ya that sounds to be good advice.. The throttle plate is what is also called a throttle butterfly..
If you don't have a tach, just turn the idle screw out until it idles as low as you can get it w/ out it trying to quit. Or you can try my method.. Before I had a tach I would judge the idle speed by ear & by watching the mirrors on the handle bars. When the idle is above 1500 rpm the mirrors will vibrate, as the rpm get to 1500 & below the vibration of the mirrors will smooth out, as the rpm get even lower the vibration of the mirrors will start to increase again, stop & turn idle back up again until the vibration of the mirrors fade again & stop there, that should put some where near 1400 - 1500 rmp.. I just recently got a tach, & personally I really don't care to much of what the tach reads as much as what my ears say & how much the mirrors vibrate.. I don't like to hear a racing raging engine of any type..
David Sr.
|
|
|
|
Post by als01seville on Dec 18, 2009 1:50:31 GMT -5
Thats what I do as well I try and get it to idle as smooth as possible and I also watch the mirrors. It will vibrate just a hair but you will know the difference from vibrating a lot or just a little bit but you will see what we are talking about. once I get it idleing as smooth as possible then I look at the tach and sure enough its around 1500 or so. Good advice by Dwild62.
Alleyoop
|
|
|
|
Post by JR on Dec 18, 2009 9:35:21 GMT -5
Put her on the center stand and turn the idle screw up until the back wheel turns at a good pace! Then slowly turn it back down until it stops and then generaly just a touch more, mine idles around 1600 rpm and sorry guys, my mirrors don't vibrate at any speed! LOL
Once you get the idle down in the range of where it needs to be then try your mixture screw. Turning it either way too much should effect the idle!
Rule of thumb, count the turns when screwiing it in (CW) until it starts to idle rough, then turn it back to exactly where you had it, and then turn it out (CCW) and count the turns until again it starts to idle rough.
Then put it right in the middle of this count or series and generally it is in the right spot then! Of course take it for a spin and see how she performs, if it isn't just right you may have to tweak it one way or another! JRR
|
|
|
|
Post by "Big Guy" on Dec 18, 2009 9:58:11 GMT -5
To try and keep this simple and without getting into a scientific discussion, you need a carb cleaning if there are no effects when you turn your screw.
-Rich
|
|
|
|
Post by speedracer12 on Dec 18, 2009 19:23:14 GMT -5
If the enricher is a possible problem can it be just disconnected electrically or does it need to be removed from the carb? Thanks
|
|
|
|
Post by Doug in San Diego on Dec 18, 2009 20:28:51 GMT -5
Solved!!
Yep the idle was to fast - I hadn't really noticed it with all my other problems.
I was pretty sure it was not the enricher, as I could always hear the idle drop down as it warmed up.
Anyhoo... I adjusted the idle, and low and behold the Air Mixture screw worked!
Needed to turn it in 1/2 turn - Now in the sweet spot
Thanks for the advice
|
|
|
|
Post by als01seville on Dec 18, 2009 20:34:30 GMT -5
Unfortunately in your case IF it is the enricher you will need a new one. Reason being is that the DEFAULT of the enricher is to be ON when cold. As the Gell inside heats up it expands and pushes the needle out to CLOSE the idle passage. So if it is your problem the needle is NOT coming out therefore you would be getting to much fuel after it warms up all the time. So if you disconnect it or take it off ITS like the choke being on all the time. You can take it out and check it as the engine warms up, you should see the needle come start to come out.
Sometimes they get stuck in the extended position and that would cause you problems starting when cold.
Alleyoop
|
|
|
|
Post by speedracer12 on Dec 18, 2009 21:18:24 GMT -5
Doug in San Diego Glad to hear your problem is solved.....
Alleyoop When I start the scoot it doesn't rev high then slow down to idle speed as the engine warms up. It starts right up first try and stays running at normal idle speed which is about 1900 RPM's. Before I started messing with the jets the scoot started went to about 3000 RPM's then as the engine warmed it slowly dropped down to idle speed. I guess my question would be is it stuck open or stuck closed? Where I live in SC a choke is not an issue the scoot sits in the garage and when it's real cold out I don't intend to ride it.
|
|
|
|
Post by JR on Dec 18, 2009 21:44:30 GMT -5
It sounds like it's stuck in the closed position unless you messed with the idle screw when you changed the jets! It could be bad or stuck in the open position and if you adjusted the ilde screw down to the 1900 range then you wouldn't know the difference!
First things first, take it out and unplug it, hook it up to a 12 volt battery and if it gets warm and the needle slowly extends then it's good and then clean the carb good with carb cleaner and generously spray it in the hole where the enricher goes!
If it tests good then put her back in set it on the center stand and start it and wait and see what happens, if she idles down after a bit then adjust the idle screw and all is solved! If it doesn't change then you've got a stopped up carb as far as the enricher goes or again for some reason it is sticking and it needs more cleaning!
If it tests bad replace! JRR
|
|
|
|
Post by als01seville on Dec 18, 2009 21:47:38 GMT -5
Hi Speedracer12, Well first I would get the Idle down to say 1500rpms. So adjust your Idle Screw the one with the Spring on it. Turn it Counter Clockwise and get your idle down to 1500. Then try starting it when cold, that will tell you if the enricher is working or not. If it has a hard time starting and you have to give it throttle to start it and to keep it running then your enricher is NOT working it is STUCK in the CLOSED position. If its working your rpms will climb to about what they are now 1900-2000 but then they will drop to 1500.
Alleyoop
|
|
|
|
Post by speedracer12 on Dec 18, 2009 22:06:20 GMT -5
Alleyoop
Thanks for the tip. I will warm it up and get the idle down to 1500 RPM's let it sit over night then start it in the morning. I'll report back and let you know. If I need to give it throttle to start it and the enricher is in the closed position can I leave it that way without doing any damage?
|
|
|
|
Post by als01seville on Dec 18, 2009 22:34:55 GMT -5
Hi Speedracer12, Sure you can leave it that way, you just will have to hold the throttle for about a minute or so just till it warms up a little. And in the summer time it probably will work just fine.
Alleyoop
|
|
|
|
Post by speedracer12 on Dec 19, 2009 8:29:04 GMT -5
Hi Alleyoop,
Well this morning was on the cold side in the high 40's and after turning down the RPM's to 1500. This morning I turned the key pressed the starter and it started right up but it went to 2500 RPM's then as it warmed it went down to 1500 and stalled. So my enricher is working. Thank you for all the help.....
|
|
|
|
Post by als01seville on Dec 19, 2009 12:14:34 GMT -5
Great!! But it should not have stalled, now you have to adjust your air/fuel mixture, your running rich, give the air/fuel mixture 1/4 turn Clockwise to lean it out a little. Your idle may go up so you may have to re-adjust your idle down a little.
Alleyoop
|
|
|
|
Post by speedracer12 on Dec 20, 2009 22:00:00 GMT -5
Alleyoop
I turned it clockwise after I had it running warm and it didn't stall but started to shake, so I went counter clockwise 3/4 of a turn and engine ran smooth and went up to about 2200 RPM's so I lowered the idle screw and it seems to be running fine. So I'm thinking it needed to run a bit more rich.
|
|
|
|
Post by als01seville on Dec 20, 2009 22:17:43 GMT -5
Fantastic Speedracer12!! If it went up to 2200 rpms thats great!! it should run really well now
as well as idle down to around 1500 Great job my man. Giving you a bone for your trial and errors, now get some riding in.
Alleyoop
|
|
|
|
Post by speedracer12 on Dec 21, 2009 8:15:44 GMT -5
Bone back to you Alleyoop for your help and patient. Hopefully tomorrow it will be a bit warmer and I'll take it out for a fun ride.
|
|
