1LikesGo Engine USA 2011 Thread
05-08-2011 | 03:46 PM
#1413
05-08-2011 | 04:52 PM
#1415
05-09-2011 | 09:22 PM
#1418
Joined: Dec 2009
Posts: 7,916
From: northern michigan
05-10-2011 | 08:11 AM
#1419
Tech Fanatic
Joined: Aug 2008
Posts: 891
From: Texas
Hey guys... I've noticed a few guys having trouble tuning with the new GXII.
After break-in, if you notice that you're having trouble with the low-speed needle and getting a proper idle, do the following.
I know this is backwards from instructions you've read, but if you're having trouble getting the right tune, try the following approach.
Set top speed needle to flush, and LSN to 1/2-1 full turn in from flush. Tune the TOP first, then tune the bottom. The HSN shouldnt be all that far in from flush- maybe an hour or two. The most precise way that I've gotten the idle dead-on, is to hold throttle at about 1/4 and listen. From 1/2 turn in, lean it till you hear it start running rough, then back it off 2 hours. You'll need to blow out the exhaust periodically. Slowly vary the throttle and adjust the LSN accordingly. Once you're happy with the LSN tune, set your idle gap.
If your LSN is farther out from flush, your HSN is too lean. This may be confusing, since it'll seem fat everywhere and wont get up to temp, but if you lean it out slightly, it'll get too lean. This is beause the LSN is still regulating fuel mixture all the way to WOT. If it's too far out, the long LSN isnt being allowed to properly regulate the fuel.
Think of it this way... you've got a garden hose with different tips on it, and you're trying to get a good stream coming out. You're not going to get anywhere unless you have the faucet at the wall allowing enough pressure to get to the hose. Make sense? ...sorry for the obscure analogy, but it's the best I could think of on allergy meds. ha.
After break-in, if you notice that you're having trouble with the low-speed needle and getting a proper idle, do the following.
I know this is backwards from instructions you've read, but if you're having trouble getting the right tune, try the following approach.
Set top speed needle to flush, and LSN to 1/2-1 full turn in from flush. Tune the TOP first, then tune the bottom. The HSN shouldnt be all that far in from flush- maybe an hour or two. The most precise way that I've gotten the idle dead-on, is to hold throttle at about 1/4 and listen. From 1/2 turn in, lean it till you hear it start running rough, then back it off 2 hours. You'll need to blow out the exhaust periodically. Slowly vary the throttle and adjust the LSN accordingly. Once you're happy with the LSN tune, set your idle gap.
If your LSN is farther out from flush, your HSN is too lean. This may be confusing, since it'll seem fat everywhere and wont get up to temp, but if you lean it out slightly, it'll get too lean. This is beause the LSN is still regulating fuel mixture all the way to WOT. If it's too far out, the long LSN isnt being allowed to properly regulate the fuel.
Think of it this way... you've got a garden hose with different tips on it, and you're trying to get a good stream coming out. You're not going to get anywhere unless you have the faucet at the wall allowing enough pressure to get to the hose. Make sense? ...sorry for the obscure analogy, but it's the best I could think of on allergy meds. ha.
05-10-2011 | 08:31 AM
#1420
Tech Fanatic
Joined: Aug 2008
Posts: 891
From: Texas
also... are any of you running the OS 2050 pipe on the GXII? what kind of runtime are you getting? One of the local guys is running one and getting unheard of runtime. I dont want to post how much until I can duplicate the same results in another location.
05-10-2011 | 09:12 AM
#1421
Hey guys... I've noticed a few guys having trouble tuning with the new GXII.
After break-in, if you notice that you're having trouble with the low-speed needle and getting a proper idle, do the following.
I know this is backwards from instructions you've read, but if you're having trouble getting the right tune, try the following approach.
Set top speed needle to flush, and LSN to 1/2-1 full turn in from flush. Tune the TOP first, then tune the bottom. The HSN shouldnt be all that far in from flush- maybe an hour or two. The most precise way that I've gotten the idle dead-on, is to hold throttle at about 1/4 and listen. From 1/2 turn in, lean it till you hear it start running rough, then back it off 2 hours. You'll need to blow out the exhaust periodically. Slowly vary the throttle and adjust the LSN accordingly. Once you're happy with the LSN tune, set your idle gap.
If your LSN is farther out from flush, your HSN is too lean. This may be confusing, since it'll seem fat everywhere and wont get up to temp, but if you lean it out slightly, it'll get too lean. This is beause the LSN is still regulating fuel mixture all the way to WOT. If it's too far out, the long LSN isnt being allowed to properly regulate the fuel.
Think of it this way... you've got a garden hose with different tips on it, and you're trying to get a good stream coming out. You're not going to get anywhere unless you have the faucet at the wall allowing enough pressure to get to the hose. Make sense? ...sorry for the obscure analogy, but it's the best I could think of on allergy meds. ha.
After break-in, if you notice that you're having trouble with the low-speed needle and getting a proper idle, do the following.
I know this is backwards from instructions you've read, but if you're having trouble getting the right tune, try the following approach.
Set top speed needle to flush, and LSN to 1/2-1 full turn in from flush. Tune the TOP first, then tune the bottom. The HSN shouldnt be all that far in from flush- maybe an hour or two. The most precise way that I've gotten the idle dead-on, is to hold throttle at about 1/4 and listen. From 1/2 turn in, lean it till you hear it start running rough, then back it off 2 hours. You'll need to blow out the exhaust periodically. Slowly vary the throttle and adjust the LSN accordingly. Once you're happy with the LSN tune, set your idle gap.
If your LSN is farther out from flush, your HSN is too lean. This may be confusing, since it'll seem fat everywhere and wont get up to temp, but if you lean it out slightly, it'll get too lean. This is beause the LSN is still regulating fuel mixture all the way to WOT. If it's too far out, the long LSN isnt being allowed to properly regulate the fuel.
Think of it this way... you've got a garden hose with different tips on it, and you're trying to get a good stream coming out. You're not going to get anywhere unless you have the faucet at the wall allowing enough pressure to get to the hose. Make sense? ...sorry for the obscure analogy, but it's the best I could think of on allergy meds. ha.
05-10-2011 | 09:29 AM
#1422
Tech Elite
Joined: Nov 2007
Posts: 2,983
From: Auckland, New Zealand
Hey guys... I've noticed a few guys having trouble tuning with the new GXII.
After break-in, if you notice that you're having trouble with the low-speed needle and getting a proper idle, do the following.
I know this is backwards from instructions you've read, but if you're having trouble getting the right tune, try the following approach.
Set top speed needle to flush, and LSN to 1/2-1 full turn in from flush. Tune the TOP first, then tune the bottom. The HSN shouldnt be all that far in from flush- maybe an hour or two. The most precise way that I've gotten the idle dead-on, is to hold throttle at about 1/4 and listen. From 1/2 turn in, lean it till you hear it start running rough, then back it off 2 hours. You'll need to blow out the exhaust periodically. Slowly vary the throttle and adjust the LSN accordingly. Once you're happy with the LSN tune, set your idle gap.
If your LSN is farther out from flush, your HSN is too lean. This may be confusing, since it'll seem fat everywhere and wont get up to temp, but if you lean it out slightly, it'll get too lean. This is beause the LSN is still regulating fuel mixture all the way to WOT. If it's too far out, the long LSN isnt being allowed to properly regulate the fuel.
Think of it this way... you've got a garden hose with different tips on it, and you're trying to get a good stream coming out. You're not going to get anywhere unless you have the faucet at the wall allowing enough pressure to get to the hose. Make sense? ...sorry for the obscure analogy, but it's the best I could think of on allergy meds. ha.
After break-in, if you notice that you're having trouble with the low-speed needle and getting a proper idle, do the following.
I know this is backwards from instructions you've read, but if you're having trouble getting the right tune, try the following approach.
Set top speed needle to flush, and LSN to 1/2-1 full turn in from flush. Tune the TOP first, then tune the bottom. The HSN shouldnt be all that far in from flush- maybe an hour or two. The most precise way that I've gotten the idle dead-on, is to hold throttle at about 1/4 and listen. From 1/2 turn in, lean it till you hear it start running rough, then back it off 2 hours. You'll need to blow out the exhaust periodically. Slowly vary the throttle and adjust the LSN accordingly. Once you're happy with the LSN tune, set your idle gap.
If your LSN is farther out from flush, your HSN is too lean. This may be confusing, since it'll seem fat everywhere and wont get up to temp, but if you lean it out slightly, it'll get too lean. This is beause the LSN is still regulating fuel mixture all the way to WOT. If it's too far out, the long LSN isnt being allowed to properly regulate the fuel.
Think of it this way... you've got a garden hose with different tips on it, and you're trying to get a good stream coming out. You're not going to get anywhere unless you have the faucet at the wall allowing enough pressure to get to the hose. Make sense? ...sorry for the obscure analogy, but it's the best I could think of on allergy meds. ha.
I still think the "cold" pinch test for the idle gap and 7 sec initial bottom end setting is the way to go, as described on our web site.
I have to disagree with you on setting the LSN, then adjusting the idle gap - this will only change the LSN setting completely.
We have found with the long needle motors (any motor in fact), it is very important to set the idle gap first - before anything else - then tuning the LSN and consequently the HSN is quite easy. If the idle gap is wrong to start with, you will chase your tail all day, unless you are an experianced tuner who knows what to listen for.
Don't want to interfere, but just couldn't agree entirely on what was written.
We have used the garden hose analogy on our web site "Tech Tips" section since it's inception, and I think it explains perfectly what is happening with the relationship between the two needles. Most people can picture this in their heads quite easily, and it normally all makes sense to them after that
.
05-10-2011 | 11:00 AM
#1423
Tech Fanatic
Joined: Aug 2008
Posts: 891
From: Texas
We have had no trouble here with the tuning Trey. I guess it's because we have been tuning the long LSN carbs all along.
I still think the "cold" pinch test for the idle gap and 7 sec initial bottom end setting is the way to go, as described on our web site.
I have to disagree with you on setting the LSN, then adjusting the idle gap - this will only change the LSN setting completely.
We have found with the long needle motors (any motor in fact), it is very important to set the idle gap first - before anything else - then tuning the LSN and consequently the HSN is quite easy. If the idle gap is wrong to start with, you will chase your tail all day, unless you are an experianced tuner who knows what to listen for.
Don't want to interfere, but just couldn't agree entirely on what was written.
We have used the garden hose analogy on our web site "Tech Tips" section since it's inception, and I think it explains perfectly what is happening with the relationship between the two needles. Most people can picture this in their heads quite easily, and it normally all makes sense to them after that .
I still think the "cold" pinch test for the idle gap and 7 sec initial bottom end setting is the way to go, as described on our web site.
I have to disagree with you on setting the LSN, then adjusting the idle gap - this will only change the LSN setting completely.
We have found with the long needle motors (any motor in fact), it is very important to set the idle gap first - before anything else - then tuning the LSN and consequently the HSN is quite easy. If the idle gap is wrong to start with, you will chase your tail all day, unless you are an experianced tuner who knows what to listen for.
Don't want to interfere, but just couldn't agree entirely on what was written.
We have used the garden hose analogy on our web site "Tech Tips" section since it's inception, and I think it explains perfectly what is happening with the relationship between the two needles. Most people can picture this in their heads quite easily, and it normally all makes sense to them after that
.Thanks for your help, Grizz. I suggested this to people that have trouble tuning after going through their "normal" routine. Funny thing is that half of the guys that are having trouble switched from OS to Go. All of them have a lot of experience with RC and tuning motors at the expert and pro levels. They came to me indicating that they couldnt get it to tune right. I took one look at these carbs and said "uh... guys..."
Mainly they had the LSN WAAAAY out.
My philosophy of tune top, then bottom, then set idle works for me... so that's what I suggest when people have problems. There is absolutely nothing wrong with setting the idle gap first. Whatever works for each tuner!
05-10-2011 | 11:07 AM
#1424
Tech Regular
iTrader: (3)
Joined: Aug 2009
Posts: 307
From: TX
I found that when my engine finally broke in (in the middle of a main of course) that it got very fat. I tried to retune it as I always had previously with the short LSN and it did not work well. The best method I found was what I had used previously on OS motors.
set idle gap to 1mm
return all needles to flush
adjust HSN first by making high speed runs until the engine revs to full potential then backing off about 1 hour.
adjust LSN until you get a smooth idle (on my prototype GXII it is about 1 and 1/2 turns in from flush.
make a few more high speed runs checking for good smoke trail and making sure the engine revs fully. At this point you may have to make a very small adjustment to the HSN probably not more than 1 hour in either direction.
Since doing this I have only had to make very small adjustments to the LSN do to changes in temperature but have not touched the HSN.
set idle gap to 1mm
return all needles to flush
adjust HSN first by making high speed runs until the engine revs to full potential then backing off about 1 hour.
adjust LSN until you get a smooth idle (on my prototype GXII it is about 1 and 1/2 turns in from flush.
make a few more high speed runs checking for good smoke trail and making sure the engine revs fully. At this point you may have to make a very small adjustment to the HSN probably not more than 1 hour in either direction.
Since doing this I have only had to make very small adjustments to the LSN do to changes in temperature but have not touched the HSN.
