78 GS1K Carb Rejet? Bad Fuel Economy - KEITH KRAUSE!

[duaneage]

I seem to recall shoving a bolt into a certain vacuum hose when I synced the carbs the first time............ :P :P :P :P

Do you still need help with these carbs Saturday or are you about there with it?

[KEITH KRAUSE]

I seem to recall shoving a bolt into a certain vacuum hose when I synced the carbs the first time............ :P :P :P :P

A golf "T" works great for this.

[Hoomgar]

Me!? Your Dad!? 8O Not with your mug....uh...I mean face.
I suggest leaving the vent nipples alone. Even a short tube causes fuel starvation. I don't know of anyone who has had a problem with a bug or dirt getting in there. Any little home made screen or downward facing tube is bound to cause problems. Hose water won't get in there if you use common sense.
It's your fault I'm worrying about every little detail now.
Mr."No one toooold me to cap the vacuum port". :P

:mrgreen:
Well I tweaked the air screws again last night just to be sure they were at max idle. I do not get enough darn variation to tell. I may never get them right. They are as close as I can get them by guessing. I really don't think I moved them much at all.

Then I set the pilots. I turned 1 in about 1/8 or less turns.
I turned 2 out about a hair less then 1/4 turn.
I turned 3 out a good full 1/3 turn
and I turned 4 out a hair. Maybe 1/8 or less.

The bike is running incredibly well and doesn't smoke as much at idle and while revving it now. But to test it I gave it a blast past a friend in his truck and he said that while standing on it I was still smoking. And it still smells really cough cough bleh cough at the tail pipe when you stop at a light or stop sign.

It has some rough spots still. And it will rev on it's own at times? Like I'll be riding and it feels like I just gave the throttle a little crack and left off but I didn't? Then it will do the oposite at times. It will feel like I left off and then back on but I didn't? What's that all about?

I know I am getting closer, but I am not there yet. Rough mileage figures showed about 24 miles to the gallon at best. But the only thing I can say good about that is that they were all hard miles. I was hot dogging it the entire tank full.

I seem to recall shoving a bolt into a certain vacuum hose when I synced the carbs the first time............ :P :P :P :P

Do you still need help with these carbs Saturday or are you about there with it?

Duane, I have the vaguest memory of that. Seriously. I don't really remember doing it but I do remember you asking for a bolt to plug a hole. I guess I wasn't paying attention.

I think I am close enough now that it is down to dialing it in and doing plug reads. I do appreciate your generous offer though. And your always welcome to drop by. That is and open offer for anytime. Bring the bike!


But now I have a new concern :?
I have taken that to another thread:

http://www.thegsresources.com/_forum/viewtopic.php?p=344379#344379

[KEITH KRAUSE]

Mark, I only have a minute. I'm trying to help you whenever I can.
I don't know if you're testing/adjusting to and from work or ?, but I'm tying to stay with you.
Without getting into details, I'd like you to do the following, unless you've made some changes yourself.
Swap the plug leads around. The leads going to 1 and 4, put on 2 and 3. Be sure they're on tight. Now put the pilot fuel screws BACK to where they were before your latest adjustments. That should mean they're all at 1 1/2 again, correct? And be sure to make accurate adjustments, not this "a little past 1/4, or just under 1/4" stuff...Make all adjustments such as 1/8, 1/4, 3/8... as best you can.
Now go test for several miles. Ride it around at least a few miles just normal. Then do a good couple of miles at 1/3 throttle, chop off and see what the plugs say again. Try to simulate this test to match the previous road/chop test you did for the last plug reads you showed me.
We're not fixing anything here, just doing some trouble shooting.

[Hoomgar]

Mark, I only have a minute. I'm trying to help you whenever I can.
I don't know if you're testing/adjusting to and from work or ?, but I'm tying to stay with you.
Without getting into details, I'd like you to do the following, unless you've made some changes yourself.
Swap the plug leads around. The leads going to 1 and 4, put on 2 and 3. Be sure they're on tight. Now put the pilot fuel screws BACK to where they were before your latest adjustments. That should mean they're all at 1 1/2 again, correct? And be sure to make accurate adjustments, not this "a little past 1/4, or just under 1/4" stuff...Make all adjustments such as 1/8, 1/4, 3/8... as best you can.
Now go test for several miles. Ride it around at least a few miles just normal. Then do a good couple of miles at 1/3 throttle, chop off and see what the plugs say again. Try to simulate this test to match the previous road/chop test you did for the last plug reads you showed me.
We're not fixing anything here, just doing some trouble shooting.

Gotcha. You want to see if it is a firing issue or carbs. I'll do that. Just swap 1&4 with 2&3


I'm testing in the evenings Keith and posting through the day. I am 3 hours ahead of you here.

[KEITH KRAUSE]

The bike is running incredibly well and doesn't smoke as much at idle and while revving it now. But to test it I gave it a blast past a friend in his truck and he said that while standing on it I was still smoking. And it still smells really cough cough bleh cough at the tail pipe when you stop at a light or stop sign.

It has some rough spots still. And it will rev on it's own at times? Like I'll be riding and it feels like I just gave the throttle a little crack and left off but I didn't? Then it will do the oposite at times. It will feel like I left off and then back on but I didn't? What's that all about?

I know I am getting closer, but I am not there yet. Rough mileage figures showed about 24 miles to the gallon at best. But the only thing I can say good about that is that they were all hard miles. I was hot dogging it the entire tank full.

Very interesting. Rich symptoms and possible lean symptoms.
At what throttle position were you when the friend saw the heavy exhaust?
This is important regarding jet needle adjustment or main jet size.
Regarding the "rough spots" you tried to describe. Are you saying the bike is surging and hesitating sometimes? Feels like the throttle is opening and closing just a l-i-t-t-l-e bit? Almost like riding into a head wind/turbulence but there's no wind? Almost a "sensation", kind of subtle but steady? Surging, etc, is always a lean condition. I know it's not the float bowl tubes still attached, but leaving those tubes on or trying to modify the vent nipples will give the same results I just described.
If the problem is more sudden or abrupt, it can still be carburetion, but many times is spark related. Wish I could ride it myself.
Also, seriously, the bike should get at least lower 30's in gas mileage.
Waiting for your latest test results to see what's going on.
A quick thought before I forget...Are you absolutely positive the vacuum hose is in good shape and fits the nipple on both ends very snugly?
And, does the Morgan Carb tool require any calibrating before use?
Be careful testing the bike Mark.

[Hoomgar]

The bike is running incredibly well and doesn't smoke as much at idle and while revving it now. But to test it I gave it a blast past a friend in his truck and he said that while standing on it I was still smoking. And it still smells really cough cough bleh cough at the tail pipe when you stop at a light or stop sign.

It has some rough spots still. And it will rev on it's own at times? Like I'll be riding and it feels like I just gave the throttle a little crack and left off but I didn't? Then it will do the oposite at times. It will feel like I left off and then back on but I didn't? What's that all about?

I know I am getting closer, but I am not there yet. Rough mileage figures showed about 24 miles to the gallon at best. But the only thing I can say good about that is that they were all hard miles. I was hot dogging it the entire tank full.

Very interesting. Rich symptoms and possible lean symptoms.
At what throttle position were you when the friend saw the heavy exhaust?
This is important regarding jet needle adjustment or main jet size.

WOT and almost redline three gears deep.

Regarding the "rough spots" you tried to describe. Are you saying the bike is surging and hesitating sometimes? Feels like the throttle is opening and closing just a l-i-t-t-l-e bit? Almost like riding into a head wind/turbulence but there's no wind? Almost a "sensation", kind of subtle but steady? Surging, etc, is always a lean condition.

That is exactly what it is doing.

I know it's not the float bowl tubes still attached, but leaving those tubes on or trying to modify the vent nipples will give the same results I just described.

No worries, those were removed, are staying off and will not have any customization done. Just open nipples the whole time.

If the problem is more sudden or abrupt, it can still be carburetion, but many times is spark related. Wish I could ride it myself.

I wish you could too Keith. It could be spark related I don't know. I have several sets of coils for it. I could use the ones off my other bike as I know they are perfect. I simply don't need them on it anymore since I put Dyna's on it. It only does this like every once in a while. Very random and very infrequent. It also isn't really bad. Most people I know wouldn't notice it but I am so anal about things I notice the lightest little skip. Not sure what it is but I think at times it may be coupled with a very slight carb cough.

Also, seriously, the bike should get at least lower 30's in gas mileage.

I so want to see that. Maybe I should go back to an air box? What do you think?

Waiting for your latest test results to see what's going on.

Well I have it tweaked really differnet right now and after taking carbs 101 last night I think I may be onto something. The pilot screws are now all only ? turn out. That?s right, only ? of a turn out. And the air screws are all 2 & ? or more turns out. The bike is finally not smoking quite as bad but still is just a bit. Especially at higher RPMs/throttle positions.

I rode it like that and it ran pretty much the same except it now runs really nice at low throttle applications. Like 1/8 and less throttle, cruising. It is smooth now. But now it likes to give a couple coughs now and then. Very slight but there just the same.

I rode it the same way as always for my plug read and the plugs came out looking exactly the same as that last picture.

I think what may be going on is that the needle circuit is opening too soon and may never be completely closing. I am thinking now that I should move the needles down one more notch by putting the clip back into the stock center position. The pilot adjustments above kind of indicate that don?t you think? (I did an overwhelming amount of carb study and tech questioning last night to understand how these things work) I believe this also because the throttle response is very sudden at only slight applications. Kind of like it's getting into the needle fairly deep right away. So we may be adjusting things at idle but actually be using just a little of the needle circuit at the same time making it really hard to dial in. Where else would that fuel be coming from now that I have the pilots down so low? Does this sound like I am thinking right? I think once I understand how these things work better I will be more affective in my trouble shooting.

A quick thought before I forget...Are you absolutely positive the vacuum hose is in good shape and fits the nipple on both ends very snugly?
And, does the Morgan Carb tool require any calibrating before use?
Be careful testing the bike Mark.

I am pretty sure the vacuum hose is good. It is one of those nice high temp hoses that is rubber with the high temp fiber wrap over it like your supposed to use. It fits on both nipples nice and snug and doesn?t wiggle around.

I looked to see if the Carbtune required calibration but I didn?t see anything about that or anything on the tool that would allow it so I don?t believe so. Anyone else know?

I?ll be careful Keith. I do a lot of riding over a ton almost all the time on these back roads here when I scoot alone. No one I ride with likes to move like that so I always have to enjoy that stuff when I am out by myself. I has been that way since my buddy I rode with in the early 90's sold his GPZ Testing is just more riding to me.

I know that's a long post but please think about my thoughts above on the jet needles. Do you think I am on the right path. I really think that makes sense.

[KEITH KRAUSE]

Mark, as usual at this time, I have about 1 minute. I'll give you my thoughts after work or a bit later because I'm busy tonight with a school function.
I know you're learning and think you're doing what's right.
Your air screws should not have been moved. Your pilots are way off anything that would work on a bike that's running correctly, regardless of your results. You're compensating. No worse word than compensating. I do have some thoughts about the needle position, but leaning them isn't one of them.
So you're saying there's no way this is a spark issue? You DID swap the coils as I asked before this test?
This bike has had a problem since the beginning with uneven burning. #3 has always been leaner. I've got mixed signals here, that's for sure.
You're bike is surging, that's a lean condition, should be the needle according to your tests. Your main appears to be rich. Etc.
Talk to you later.

[Hoomgar]

Mark, as usual at this time, I have about 1 minute. I'll give you my thoughts after work or a bit later because I'm busy tonight with a school function.
I know you're learning and think you're doing what's right.
Your air screws should not have been moved. Your pilots are way off anything that would work on a bike that's running correctly, regardless of your results. You're compensating. No worse word than compensating. I do have some thoughts about the needle position, but leaning them isn't one of them.
So you're saying there's no way this is a spark issue? You DID swap the coils as I asked before this test?
This bike has had a problem since the beginning with uneven burning. #3 has always been leaner. I've got mixed signals here, that's for sure.
You're bike is surging, that's a lean condition, should be the needle according to your tests. Your main appears to be rich. Etc.
Talk to you later.

When you get time Keith. I appreciate all the free help buddy. Your commenting on what I was trying to say. I KNOW the screws are way off and that I am compensating BIG TIME! That is my point. I know that isn't right. And therefor I am thinking what I am thinking about the needle circuit. Chew on that a bit more before you reply. If I am not thinking right I want to know but right now that is making so much sense to me that it looks like it really is the issue.

As for swapping the coils, I tried but no go there. I need to reroute some wires. the monkies worked on that too is looks like :x

I'll try to get that sorted tonight. I haven't had a lot of time lately and right now to be honest I need to cool down from what I found out in my oil leak thread. I am ready to burst and need to chill a bit.

Let me know what you think about the needle cicuit analysis I made and in the mean time I'll get the wires rerouted so I can swap those coils.

Thx for stickin with me this long Keith. You are a friend indeed.

[KEITH KRAUSE]

OK. Since you're not in the mood to be reprimanded, I'll skip most of what I was going to say. I just read about how the bike has been worked on by butchers in the past. This just adds fuel to the fire. Anything's possible. :roll:
As you said earlier, I am serious about the advice I give. I think things through. I kept records of final jetting adjustments on several 1000's. I've never had a problem escape me for too long on a bike I'm doing the actual work on. I've learned all about compensation jetting. At first, it may seem like it works, but it doesn't.
There's nothing unique about your mod's. Your bike MUST fit the pattern that others fit into when re-jetting. All the other bikes work well, allthough sometimes with minor "driveability" issues that can't be reasonably jetted out. Surging is not one of them, neither is really poor gas mileage. If yours doesn't fit the pattern, then there's something wrong that I have to depend on you for help. All problems have a perfectly good reason for happening. There are no real mysteries.
I'll still wait for the coil leads to be swapped around, because it's too important. I would like you to swap the leads, NOT use some different coils. The pilot fuel and side air screws have to go back where they were too, or reasonably close. I can only "do" things as I would if the bike was in my hands.
I have many ideas and there are many things that can cause your bike to do the things it's doing. We don't always like some of the possibilities. Just one example: worn jet needles.
Like I said, it makes sense to swap the leads. Why? Here's a very possible scenario. Your plug colors, at least from what I can see, show 2/3 lean, 1/4 much richer, despite all work done in an identical way. I believe this could be spark and needle related. If the spark is actually weak to 1/4, the lean mixture will read as richer. The good spark at 2/3 is simply burning the plug clean because the needles are too lean.
I hoped that we could at least try adjusting the pilot screws before giving up on the current needle set up. But I can only suggest things. I can't make you stay with something before going to the next attempt.
I've said from the beginning that the stock needles don't give good results as often as jet kits.
Also, I've never had a K&N pod filtered 1000 run right with the stock needle in the 4th position. The stock needle has always been set at the bottom position, and sometimes that's not enough.
As for your needle question/suggestion, think about this. A 1000 with a stock airbox and exhaust (very restrictive) has the needle set in the 3rd position. That's where you're thinking of putting the needle. You wouldn't be allowing for the pods or pipe at all. It would surge much worse than it's doing now. How could a K&N pod filtered bike run right on the stock jetting? Your pilot screws were not set anywhere close (from the factory)to where you have them now.
The only thing I'm a little surprised about is the main may be too big. Your wide open heavy exhaust suggests that. BUT, that can still be a weak spark at 1/4 causing this. It may not be a weak spark, but I have to suggest it and you must admit it fits. If I'm right, the possible weak spark at 1/4 explains everything. Uneven plug reads...2 cylinders surging... 2 cylinders wasting gas...
If I'm not right, then something else is causing these problems.
I also still suspect your K&N's may have flow problems due to poor maintenance. It would explain the main jet being "rich", etc. Again, maybe they're fine, but I've seen it happen.
Compensating won't fix this stuff.

[Hoomgar]

I am going to digest all of that and work heavily on that this week Keith. I didn't get much time this weekend. Your thinking seems all good. I wish I would have logged on and read that before yesterday. I already moved my needles down a notch. I will give it a quick try since it is already done and it should reveal itself very quickly if it is way leaner.

If that is the case I will put it back to where it was or would you like me to just move it at that point up the whole way?

I will get one plug read with it the way it is so I have something to go against since I made this change and then I will reverse the coils. Some idiot cut the wires when putting news ends on them so that they are so short now that I cannot reverse them the way they are. I am going to have to add wire.

I'll keep you posted.

[KEITH KRAUSE]

If that is the case I will put it back to where it was or would you like me to just move it at that point up the whole way?

I will get one plug read with it the way it is so I have something to go against since I made this change and then I will reverse the coils.

I would have liked to see what the coil swap would do to the plug reads.
But like I said, I have more than a weak coil on my mind. But the test could really help.
Leaning the needles even more may change the reads I expected. An overly lean mixture will possibly help hide a weaker spark and make all 4 plugs look closer in color. I wanted to see (with the coil swap the ONLY change) if 2/3 got darker and 1/4 got lighter.
You can still test for your needle change and take reads anyway. I think 2/3 will be even whiter, and 1/4 just lighter than they were. But you need to take the reads at 1/3 throttle. I'm still surprised you say the plugs look quite different than the pic's show. Sure makes it harder.
If you don't like the results of putting the needles at #3 position, and I'm sure you won't, THEN try the coil swap, leave the needles at #3, and see what it does to those reads. Before the coil swap, I'm expecting 2/3 to be even leaner and 1/4 to be lighter than they were when you had the needles at #4. After the coil swap, see if 2/3 become darker and 1/4 lighten up even more.
Without this test, I really can't say what needle position is going to be best for this bike. My experience says #5 position, or a DJ kit. But with your apparent surging, uneven reads, and poor fuel mileage all at the same time, I need to try to trouble shoot first.
Remember, every time you move the needles, you must re-synch these carbs to get accurate reads/best performance. You have to put the air and pilot fuel screws back to where they were too.

[Hoomgar]

OK Keith. I'll try to get some results to post tonight. Weather permitting.

One thing though, you aren't thinking there are any DJ parts in these carbs are you? These carbs are 100% Mikuni. There are no DJ parts at all in them. Just in case that matters.

[KEITH KRAUSE]

OK Keith.
One thing though, you aren't thinking there are any DJ parts in these carbs are you? These carbs are 100% Mikuni. There are no DJ parts at all in them. Just in case that matters.

Nope. We're working with Mikuni mains and a stock jet needle.

[Hoomgar]

OK so Keith and I are doing some coil trouble shooting ideas on my bike.
He suggests I do the old switch of the plug wires test.

Well, when I swap my plug wires 1&4 with 2&3 the bike will not fire.
It will not start even with a bump start. It loads up on fuel and back
fires out the pipe.

Switch the wires back, she fires right off.

We both agree that isn't right. Anyone have any ideas what that would be?
Earl, you even seen that before? I am hoping someone has run into this
before and can shed some light on this.

I am at a loss to explain this one.