thejackrabbit
Member
in the jetting database what are people referring to when it says the slide is notched or not?
Slide notched or not?
- Thread starter thejackrabbit
- Start date
roverhybrids
Member
here you go:
thejackrabbit
Member
so say my bikes idle changes in less than half a turn of the knob would cutting a notch make the idle more consistent?
Jakobi
Super Moderator
I'm not a fan of the notch..
The idle area is a fine balance between air screw, pilot jet, needle diameter, and slide cutaway. Then if you add the notch you get another variable to deal with as well.
The goal here is to get the bike idling with the slide in a nice low position. If the spring on the adjuster is bound up and its holding the slide way up in order to idle you'll bypass the straight section of the needle which leads to even more inconsistancies as you're now adding more fuel due to the taper each time you raise the slide. The stock needle has a really short straight section, and is too rich for most the newer AS2 carbs. Net result is a bike that won't idle consistantly.
The idle area is a fine balance between air screw, pilot jet, needle diameter, and slide cutaway. Then if you add the notch you get another variable to deal with as well.
The goal here is to get the bike idling with the slide in a nice low position. If the spring on the adjuster is bound up and its holding the slide way up in order to idle you'll bypass the straight section of the needle which leads to even more inconsistancies as you're now adding more fuel due to the taper each time you raise the slide. The stock needle has a really short straight section, and is too rich for most the newer AS2 carbs. Net result is a bike that won't idle consistantly.
I look at a bit differently. The notch passes air for idling and as a result the slide can be closed further than non-notched. This would help the slide to stay on the short shank of the stock needle. The problem is that the stock needle sucks anyway.
I feel that a fat pilot with a long shank needle is good. The fat pilot reduces the chance of a hanging idle and the long shank creates a bit of a lean hole coming off idle. This gives good off idle operation. I rarely need more than 1/3 throttle for my type of riding.
I feel that a fat pilot with a long shank needle is good. The fat pilot reduces the chance of a hanging idle and the long shank creates a bit of a lean hole coming off idle. This gives good off idle operation. I rarely need more than 1/3 throttle for my type of riding.
thejackrabbit
Member
is it possible to cut a notch out? looks like it's height lines up with the 1st ledge after the bottom and how wide is opening 1mm? 2?
bowhunter007
New member
I would assume so...providing it's machined vs hacksaw.
Well in desperation after a long standing issue with idle problems & slow speed loading up I added a notch. So far I have the best idle I ever had.
So 2005 Ec 250, modded head and squish set. DDK needle, # 8 slide (was a 7 that I cut on a milling m/c) 42 pilot and 175 main
Now here's the thing: prior to the notch the idle mixture screw made no difference, nor did anything else I tried including:
30 - 48 pilot inclusive
N1ef, JD blue needles
The bike would idle on cold start (yet needed choke to fire up) then as it warmed the idle would falter and stall, when warm it simply didn't idle. It was difficult to ride slow technical as it would load up and then clear out when the throttle was opened, power delivery was brutal. Just winding on to 1/4 - 3/8 throttle and holding there power would build and snap the front wheel up.
After notching the mixture screw actually works, wind it in and it stalls, wind it out far enough and the bike will begin to bog as throttle is snapped open, find a mid point and its happy.
From my tests over the last few days I know putting a friends carb on it also solved the idle - that was configured with a N1ef, 180main, 38 pilot and #6 slide with no notch. Conclusion : something about my carb is different but no amount of stripping, checking and measuring has identified it. (I even had the bore of the needle jet measured on a specialist computer measuring m/c)
So I will test more tomorrow, I am a little concerned the #8 slide mod may now cause a lean condition, but the bike idles, is smoother in delivery and faced with a bill for 250 Pounds for a new carb notching it seems worth a shot.
I will update.....
So 2005 Ec 250, modded head and squish set. DDK needle, # 8 slide (was a 7 that I cut on a milling m/c) 42 pilot and 175 main
Now here's the thing: prior to the notch the idle mixture screw made no difference, nor did anything else I tried including:
30 - 48 pilot inclusive
N1ef, JD blue needles
The bike would idle on cold start (yet needed choke to fire up) then as it warmed the idle would falter and stall, when warm it simply didn't idle. It was difficult to ride slow technical as it would load up and then clear out when the throttle was opened, power delivery was brutal. Just winding on to 1/4 - 3/8 throttle and holding there power would build and snap the front wheel up.
After notching the mixture screw actually works, wind it in and it stalls, wind it out far enough and the bike will begin to bog as throttle is snapped open, find a mid point and its happy.
From my tests over the last few days I know putting a friends carb on it also solved the idle - that was configured with a N1ef, 180main, 38 pilot and #6 slide with no notch. Conclusion : something about my carb is different but no amount of stripping, checking and measuring has identified it. (I even had the bore of the needle jet measured on a specialist computer measuring m/c)
So I will test more tomorrow, I am a little concerned the #8 slide mod may now cause a lean condition, but the bike idles, is smoother in delivery and faced with a bill for 250 Pounds for a new carb notching it seems worth a shot.
I will update.....
Last edited:
Interesting info!
I'm wondering if my ec300 has to deal with this too.
Bike is running with N3CJ pilot 42 and when setting up the idle, the idlescrew is not responding until is it almost screwed in completly! Then it is ideling very low but strong.
Always wonderd if that was normal.
Has this a relation with the notch mod?
I'm wondering if my ec300 has to deal with this too.
Bike is running with N3CJ pilot 42 and when setting up the idle, the idlescrew is not responding until is it almost screwed in completly! Then it is ideling very low but strong.
Always wonderd if that was normal.
Has this a relation with the notch mod?
So an update:
The bike is way better than its ever been, power is smoother and gas usage is now similar to other bikes. idle was ok but then as the day warmed up it began to stall, I didn't adjust air screw and I 'm sure that would have helped. Still have further to go to improve things but its a good start....
BSM2: What year is your bike, and what carb do you have (round top or plate with 2 screws?)
I would think you need to go up a pilot size first.
Cheers Andy
The bike is way better than its ever been, power is smoother and gas usage is now similar to other bikes. idle was ok but then as the day warmed up it began to stall, I didn't adjust air screw and I 'm sure that would have helped. Still have further to go to improve things but its a good start....
BSM2: What year is your bike, and what carb do you have (round top or plate with 2 screws?)
I would think you need to go up a pilot size first.
Cheers Andy
