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

[Hoomgar]

0-rings are ordered and paid for. Hopefully they will arrive soon. I'll need that bench sync info you mentioned Keith? Also, if you didn't see it, can you look at my questions in my last post? Thx

When we figure these babies out and get them right I am going to rebuild the other set of carbs I have the same exact way and leave them dry stored so I have a spare ready to go when the time comes. Sweet

[KEITH KRAUSE]

The orange, pliable stuff in the oil looks like a type of sealant that oozed out during engine/case assembly.
Clean the floats with a toothbrush. If the stain persists, don't worry about it. Be sure to set them as I said.
Yes, the needles should all be identical. I hope there wasn't some reason that someone would try to make this compensating adjustment. Maybe just a mistake I hope.
I don't know why, but I keep getting mixed up with which set of carbs you're working with. Neither set really has a DJ kit?? The stock needles many times just don't work. Anyway, going by those plug reads, you should try raising the needles another position. Put the e-clip in the bottom position if these are stockers. If there are only 5 positions, then these are stock needles.
Try 130 Mikuni main jets.
The pilot fuel screws underneath are not always set the same, but are generally within a 1/2 turn of each other. There's no reason to think yours are set wrong at this time, except for #4. I don't know where it's at, but try an additional 1/4 turn in for starters. GENERALLY, these screws are around 1 1/2 turns out with pods/pipe. Use a mirror and light, and don't get crossed up and turn them the wrong way. You want to turn that screw in, clockwise.
Before taking any more reads, I suggest waiting to do the vacuum synch. You'll get more accurate reads then.
Hope I answered your questions. Gotta get to work now.
I plan to post detailed info about the carb bench synch tonight after work. A good bench synch will make the vacuum synch much quicker/easier. Remember, you'll need a couple of larger fans to cool the motor when synching.

[Hoomgar]

The orange, pliable stuff in the oil looks like a type of sealant that oozed out during engine/case assembly.
Clean the floats with a toothbrush. If the stain persists, don't worry about it. Be sure to set them as I said.
Yes, the needles should all be identical. I hope there wasn't some reason that someone would try to make this compensating adjustment. Maybe just a mistake I hope.
I don't know why, but I keep getting mixed up with which set of carbs you're working with. Neither set really has a DJ kit?? The stock needles many times just don't work. Anyway, going by those plug reads, you should try raising the needles another position. Put the e-clip in the bottom position if these are stockers. If there are only 5 positions, then these are stock needles.
Try 130 Mikuni main jets.
The pilot fuel screws underneath are not always set the same, but are generally within a 1/2 turn of each other. There's no reason to think yours are set wrong at this time, except for #4. I don't know where it's at, but try an additional 1/4 turn in for starters. GENERALLY, these screws are around 1 1/2 turns out with pods/pipe. Use a mirror and light, and don't get crossed up and turn them the wrong way. You want to turn that screw in, clockwise.
Before taking any more reads, I suggest waiting to do the vacuum synch. You'll get more accurate reads then.
Hope I answered your questions. Gotta get to work now.
I plan to post detailed info about the carb bench synch tonight after work. A good bench synch will make the vacuum synch much quicker/easier. Remember, you'll need a couple of larger fans to cool the motor when synching.

Sorry for the confusion Keith. Yes I am playing with two sets of carbs. Just forget about the set I post about last. That is what that plug read was from. Those are the carbs off my other GS and have what looks like Mikuni 118 mains but there is no marking I can see that designates manufacture. I believe both carbs have Mikuni jets in them. Just forget about this set; let's work on the set off the bike.

That set is the one I have just completely disassembled and cleaned. I just ordered new o-rings from Robert and also a gasket set off eBay. The mains were labeled as 132.5. If you think these are good we'll go with them. Or should I look for something smaller? The needles only have the 5 slots so these are most likely Mikuni parts. The other marking on the 132.5 mains was an R followed by what looks like two squares.

Keith, I can learn anything but it has to click first and those instructions for setting the float levels do not click. I need a picture or something to know what I am measuring. What does "tweaked" mean? Crocked maybe?

I need help with that since that will be next upon assembly. Where did you order your vacuum tool from or what one do you recommend I get for me? I need to get it ordered and have no idea so I will go with your recommendation.

[KEITH KRAUSE]

Hi Mark. The tool I have now is a Motion Pro. About $40. Works well. Only negative (with any mercury tool) is you can get condensation mixed with the mercury if you take too long to synch. Not a major problem, just an annoyance. The Morgan Carb Tune uses metal rods and doesn't have this problem. Mercury can spill too if you knock over the tool. The Morgan is about $80? I have no problem with the Motion Pro, but the Morgan is a fine tool if $ doesn't matter.
Yes, you can try the 132.5 Mikuni mains. I guessed 130, so that's close enough to try.
The stock jet needles e-clips will have to go in the botton position and we'll hope that does it.
The factory float levels are to be between .90 and .98". I set mine at .94".
Just make sure you hold the measuring tool reasonably straight up and down. Because of the "range" in the setting, you have a little room for error. As for "tweaked" floats, before starting final adjustment, if needed, make sure both sides of each float measure the same. They're sometimes bent (one side higher than the other). You can't accurately adjust them until they're even. Gently bend one side a little to match the other closely if needed. To measure, you need some verniers.
Float level is CRITICAL to good performance, so do it right. Make sure all the float valves are in good condition. The little pin under spring tension must have no slack in its travel. If you GENTLY press it in a little, it should come back out completely under spring tension. If you can actually pull the tip out a little further (slack), the spring is weak and the valve should be replaced. Also, check the pointed tip of the valve where it seats into the brass seat. If a groove is worn around the tip too deep, the valve will allow gas to leak out the bowl overflow line. Keep each float valve with its brass seat, they wear as a unit. If any valve looks worn out or the spring/tip is weak, don't bother to set the float level to that carb yet, replace the valve.
To measure, make sure the bowl gasket is removed. On the carb body, where the gasket sits, you'll see a small, thin ridge. This helps the gasket seal. Don't let your measuring tool sit on top this ridge. Put the tip of your tool on the flat surface. With the floats resting on the float valve, you want to measure to the highest part of the round float body. With the carb at eye level, slide the tool over the top of the float. It should just barely graze the float, not pushing the float downward any more than a graze. Just be sure to hold the tool straight and double check your work. If you have to make an adjustment, you bend the little tab that contacts the valve tip. In this INVERTED position, bending the tab UP, will LOWER the measurement, and vice-versa. Don't be rough with the float when bending the tab. Hold it so you don't tweak things. I put my middle and index fingers under the float so the tab is right between them. I then push down on the tab with a small screwdriver tip to make an adjustment. If you push too far and need to push it the other way, just flip the float over. A little tab movement changes the measurement a lot. It takes practice sometimes. Be picky and set them right.
Just a thought, in case you don't know: be sure you install the float correctly, not upside down as others have done. You can easily see the little shiny "rub mark" on the float tab where it contacts the float valve tip.
Bench synch info to follow.

[Hoomgar]

OK I think I follow you now. I missed the whole "inverted" part in your last post. It makes sense now. Plus I found that in my manuals so I will get-r-done I am going to wait for my rebuild kits to come so I can use the new float valve needles and seats. Then I will do it up.

Right now I am playing around with this other set trying to dial it in. :?
Just something to play with and learn.

[KEITH KRAUSE]

Well then, here's something to play around with and learn. The VM bench synch.
FULLY CLOSED POSITION first ('78/79 GS1000): Take the tops off the carbs. Throttle return spring INSTALLED. Be sure the throttle valve arms and throttle pulley are torqued to the throttle shaft and the throttle shaft stopper plate is tightened.
Turn the idle adjuster knob to make a good clearance between its tip and the throttle pulley. Above each slide is the slotted adjuster screw and its holding nut. Loosen the holding nuts. Hold the carbs with the ENGINE side facing you. Look at the small nick at the bottom of the slide. When done, you want these to all look as close to uniform as possible. On the 1000, you can start with any carb. Turn the slotted screw to fully close or seat, the throttle valve. Don't tighten it down. Just seat the valve. When you see the valve stop dropping, stop turning the screw. You'll find that the screws are very sensitive. It does take decent eye sight and a careful hand. Once the valve is fully closed, hold the adjuster screw STILL and tighten the holder nut to 3.5 ft/lb. NO MORE. Repeat to the others. When done, the small nicks should look uniform.
Now the FULLY OPEN POSITION: There's a slotted screw under spring tension mounted on the carb bracket. When you open the throttle fully, the pulley will stop when it hits this screw. Turn the carbs so the FILTER side is facing you. Raise the valves by pushing up the throttle pulley until it stops and hold it. Look up and inside the bore. Note the bottom of each valve. The bottom of all the valves must be between .5mm and 1mm above the top of the intake chamber. Turn the slotted screw in to decrease the gap, out to increase. It usually only takes a 1/2 turn or so, if needed.
Now turn up the idle adjuster knob enough so the bike will idle when you do the vacuum tool synch.
A good bench synch will make the vacuum synch easier/quicker.
Use two fans. Stop if you think the motor's getting too hot. Remember to adjust the side air screws by using the highest rpm method before the synch. This is to be done on a warmed up engine. The ignition timing, tappet clearances, and throttle cable slack must be correct too. Clean and oil those K&N's with K&N filter oil and mount.
Note the initial vacuum levels at start up. I synch at about 3,000 rpm's. Don't rev the bike suddenly or you'll suck up mercury. Easy on the throttle. Adjust the higher level(s) to match the lower levels. Don't over tighten the adjuster screws. Get the levels as close as possible. If you can get them so the difference between the highest and lowest level is about 1/2", that's good. Double check all adjustments by slowly opening/closing the valves. It takes practice. You can do it.
Any questions, let me know.

[Hoomgar]

Awesome Keith, thx So yes some quick questions. (I sure hope I am not burning you out? Once I learn this stuff I will be able to help others as well)

The ignition timing, tappet clearances, and throttle cable slack must be correct too. Clean and oil those K&N's with K&N filter oil and mount.

1. Ignition timing is still done via points and condensers. I need tips.

2. Tappet clearances? What is/are they/that? I am out of my element, please help.

3. Throttle cable slack. I think I do this right. I always adjust the cables so that there is only the slightest detectable slack on both cables when the throttle is sitting in the returned position. It feels right that way to me. Is that correct?

K&N filter oil, who would have thought it? I thought they were dry filters? I have been using them for over 14 years and never did or knew that. Learn something everyday I always just cleaned them out with gas, polished the chrome with chrome cleaner and put them back on. I will get some of this oil.

No worries about mercury getting sucked in. I just bit the bullet and ordered this set

http://www.ekmpowershop.com/ekmps/shops/carbtune/index.asp?function=DISPLAYPRODUCT&productid=26

It's a tool investment and I never feel bad about that even though it was a tad pricey. I want to be able to do tune ups that are spot on and help others with the same. The time to learn is now!

[Hoomgar]

Hey guys, should I buy this tool for setting my timing or is there another way you suggest? I am pressing the "Ask Earl" button here. I know you know the best way to set timing on these old scoots Earl. Should I use a light like this or do you do it some other way? And if by light, is this a good one or should I look for another product? Give me your recommendation please.

Thanks

Here is the light. It's hand made.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=4544529879&sspagename=STRK%3AMEWA%3AIT

[KEITH KRAUSE]

Mark, I can't vouch for that timing tool, but it says it does the job.(?)
It's been a long time since I adjusted points. I've played with some older British bikes recently, but mostly all upgraded ignitions any more. I used to use a regular timing light and seperate dwell meter for the points on my bike (24+ years ago).
You have to have good condition points to begin with, then you set their gap. Then the timing. Earl could probably explain it better with all the experience he's had with 'em. I could, but without pictures to point to the adjustment screws, marks, etc, it would be kind of drawn out and might sound tedious. You don't have a manual of any kind? Even a cheaper manual will show this procedure? If Earl doesn't show up, I'll describe the procedure, but I don't know if I'll make it as clear as he has in the past. A search would show past posts? With pictures, it's easy. Without pictures, a little more difficult. How about a Dyna ignition to bring the bike into the 21st century and really improve the spark and overall performance? If you're going to keep the bike some time, it's $ well spent. You're made of money, right?
As for tappet clearances, these should be adjusted at the rebuild. The clearances have to be set between .03 and .08mm on a stone cold motor.
The throttle cable slack should be about 1/12" or so on the pull cable. The return cable should be zero or nearly zero slack.
If you have K&N gauze filters, they MUST be oiled and you should only use their oil. Other oils can restrict their flow. NEVER use gas to clean them. Use K&N cleaner or a mild dish soap/detergent. Don't "dunk" them in cleaner either, just a 1/4" deep cleaner in a pan. Lay them in this and rotate them to get them clean. "Swish" them around, back and forth to remove dirt. Also, be sure to always rinse them from the INSIDE-OUT. Never use high pressure water either. Always allow them to air dry, no serious heat. K&N's are bitchen filters but you have to take care of them. I can't say for sure, but yours could have their flow characteristics compromised if they've been handled wrong in the past. Hope not. Don't know how you'd ever know either, unless you tested them against new filters. Hope this helps you out.

[Hoomgar]

Thx Keith. I know how to set timing on a car. So I imagine it is very similar on as bike then. My question really was if that was a good light for my bike or not? If your saying I can use my 4-6-8 cylinder light gun and dwell meter from my Chevy days then I am set. I have most likely every service manual made for this bike but they don't know if that light is any good or not That was my question. I think I will follow your advice and use my timing gun for my car. But it is inductive not direct connect and I wasn't sure if that would work on my bike or not?

I still don't know what a tappet is so I guess I'll look that one up. The manuals suck. It's so dang hard to find anything in them. They are about as organized as a city phone book.

One thing, you said to clean the floats with a tooth brush but what is a safe cleaner to use on them? Should I use gas? Carb cleaner? I don't know what that material is and don't want to damage it.

As for the ignition. I may "upgrade" the Dyna ignition in my 1085 someday and when I do I'll put the one that is currently in it into this bike. Until then, it's points and condensers

Still waiting on parts :?

Made of money? You have got to be kidding me! When this project is done that is it! I wont have more cash until this time again next year when the tax man gives my money back once more. Give me a break! :P

Thx for all the help.

[KEITH KRAUSE]

Regular "car" timing light. That's what I still use to check my Dyna once in a blue moon. We set my bud's Norton 850 point gap the other day with just a feeler gauge actually. I can give you the point gap (dwell) and timing info straight from the factory manual if you like. They do you use their own tester/light. Don't know if that technically changes the procedure info? It's still much easier to explain with the pic's pointing to things.
The tappet clearance is made by installing the correct thickness of shims. This adjustment is very important to performance. I've made several posts about it in the past, including a detailed procedure. You need a tappet depressor tool to change the shims. About $30. If you want the procedure, I can send that too. Your mechanic/builder should do this as part of the rebuild though.
I just rinse off my floats in gas. I can't imagine needing anything else to clean them off. They can't be that bad?

[Hoomgar]

Keith a couple things I think I am confusing you on just so I don't have you all mixed up with my questions. So sorry about that.

Your mechanic/builder should do this as part of the rebuild though.

This is a new bike were working on here. Not my project bike. I am not opening the engine on this thing unless absolutely needed. And my mechanic doesn't even know I have this as that could affect the work he is doing for me on my project bike. Please see this thread: http://www.thegsresources.com/_forum...ic.php?t=34175

The tappet clearance is made by installing the correct thickness of shims. This adjustment is very important to performance. I've made several posts about it in the past, including a detailed procedure. You need a tappet depressor tool to change the shims. About $30. If you want the procedure, I can send that too.

Tappets, I simply do not know what they actually "are" but I will look them up. I wasn't asking about how to adjust them but just what they are. I assume from your last post they are somehow related to the valves? That means under covers! I won?t be looking at them. I was only asking what they were, I'm easy

I can give you the point gap (dwell) and timing info straight from the factory manual if you like.

Manuals, I have them all! Factory, Clymer, Haynes, Factory supplemental. I think I have every manual made for all my bikes. I will look that stuff up. I can probably do most of it that way now instead of bugging everyone with questions and only pop in as I have a few that I cannot figure out. I need to learn to decode these things. They are confusing at best :?

I just rinse off my floats in gas. I can't imagine needing anything else to clean them off. They can't be that bad?

That's what I'll do then They are pretty crappy looking.


Sorry about all the confusion Keith. I know I tend to jump around a lot at times and lose people. Sometimes I think out loud and confuse people. I'll try to just ask very specific and less broad questions from now on. I appreciate all the info.

As soon as I get the parts in and get these back together I will bench sync them as well as set the floats. Then when my carbtune gets here I'll sync them up. Here is hoping all goes well 8-[

[KEITH KRAUSE]

Sorry Mark about the confusion. I try to help so many members that I can get mixed up sometimes.
Suzuki describes it as "tappet clearance". When your cam lobe is in a certain position, there needs to be a range of clearance between the lobe and the shim above the valve. Different size shims are available to adjust this clearance. Too tight, and the valve can burn, too loose and the valve wear will accelerate and be noisy. You can generally hear the "ticking and clicking" going on in that area if the clearances are too wide. To do the most accurate vacuum synch, these need to be adjusted correctly. Basic maintenance.

[Hoomgar]

The apologies are mine Keith

I do it to everyone, don't feel bad


Anyway, my engine seems really tight and quiet for an old GS. My other bike was alot louder in the engine at idle than this one is. None of the traditional rattle and knock I was used to. I am going to let it go. When I ever get another ride going I will tear this one apart. until then it's just about getting the carbs on and as good as I can and go with it.

I already am stocking up on all the needed gaskets and stuff for that work in the future.

I hope when I get home my o-rings at least are there so i can start on this.

[KEITH KRAUSE]

Good luck on the carbs. If anything hangs you up, give a yell.
I gave you my jetting suggestions. Remember to seat the pilot fuel screws only lightly when you adjust them.
Now might be a good time to replace the throttle return spring with something a little lighter, if you think it's too hard on the wrist. I do.