'78 GS1000E Up and running, Almost ready for paint.

[ReTread]

I've been commuting on my 78 Skunk as of late. She's bone stock except for the air filter. The rear part of the air box was missing so I fabbed up a polypropylene tube filter similar to a UNI. Though the jetting is not spot on, the plug reading two days ago looked good.

I can be a little heavy handed on the throttle when it's safe to do so.

The best MPG she's gotten is 42 with the worst being 38.

When fully sorted it might see 45 mpg tops.

 

[KEITH KRAUSE]

Keith, I really don't enough about the carburetors to comment on anything but what I can see and measure. I had these carbs built by George Lesho, and part of his comment on his setup was to keep an eye on the plugs because they might be a little on the rich side where the normal VM26 on the GS1000 is on the lean side. My speedometer matches the town 25MPH radar signs, if that means anything, and the plugs look just about perfect, but I can have a second opinion on that, several of my friends are mechanics. this motor as I had said before was not well maintained, and it is using quite a bit of oil recently. It overheated badly the other night going up the mountain in a traffic jam before I could find a place to pull off. The motor is likely to be changed very soon, I have two others that should be in very good shape, and may only need valve seals.

Allright. As I said before I'm not here to argue. People here know me. I care about this stuff. If I believe somethings wrong I speak up.
I'd like to know what the jetting is and then I could tell you if it's in the ballpark or not. I've jetted many of these bikes and helped even more at this site. I once got in an argument with George over some things. I'm sure he may be a good guy but I know some of his comments were just to make money and not based on actual testing.
Your bike is generally on the jet needle with some pilot jet/cut-away overlap effect, the type of riding we most do. Your engine may be getting weak but over-heating is often a sign of lean jetting. I've read in the past that George made adjustments that I know result in lean mixtures. I spoke up about that and some of his basic tuning practices and we got into it.
One of the easiest things in the world to do is run a bike lean and think it's running well. Lean, to a point, makes more power. But if the bike is tested correctly the lean mixture will show itself.

 

[tkent02]

As for your 1100 and how it compared mileage wise with the punched out 1100, how do you explain him getting better mileage than you, if in fact both bikes are jetted properly? I mean, how can a modded 1100 achieve better mileage than your stocker?

I don't claim to know how it works, I know what I saw at the pump.
My stocker isn't jetted perfectly, it's only how it came from Suzuki.
It runs a little weak at low RPMs, have not completely sorted it out yet.
The other bike ran much stronger at any RPM, and used less fuel.

 

[Guest]

Keith, PM me, I am interested in your opinions on my setup, but I don't think an open forum is the place to do it since there is a third party not part of the post.

 

[KEITH KRAUSE]

Keith, PM me, I am interested in your opinions on my setup, but I don't think an open forum is the place to do it since there is a third party not part of the post.

I stopped doing PM's a long time ago because it got to be a part time job. I felt obligated to reply.
I'll open it up and PM you if you still want to but I've always felt the forum is the place to reply. We all chime in and learn. I have nothing to hide and don't need to defend things I've said. If you speak about something you don't really understand or you BS people, then you have something to defend or hide.
I'm really quite surprised how simple it is to jet your model. There's a narrow range of jetting that works here. Even Dynojet gives info that's a bit off the mark. They say in their jet kit sheet that it's not uncommon to have to move the jet needle 3 full positions to achieve a good mixture and they state position 1 1/2 is a good baseline to start jetting the needle. Not so. I've never seen this model run well at that baseline setting. In fact, that setting will put a hole in your piston if you go out and do any kind of riding beyond short trips. Yet some people follow that advice, do a quick test run and call it good. They really don't know what running "fat" or "surging" even is.
I own this model. I have for 30 years. Jetting is my niche here. I don't know it all but I try to share. If I read something that's not right, I say something. If you read old advertisements and specs about our 1000's you'll see the mpg range is generally 35 to 45. Mag' road tests are in that range but closer to the lower number.
If you increase the air into the motor you have to increase the fuel or it'll be lean. Pods are a big increase. Pods and lean jetting will increase your mpg over stock. You can overheat a motor with poor jetting. Fuel mileage will be less if you properly re-jet. It can't be any other way.
As I said earlier, jetting is fairly easy on this bike. You get the other basic tuning done and there's not much range of jetting that you have to test. If your motor is in questionable condition then that needs to be fixed first. If you have poor compression then you fix that and then work on the jetting.
If you really think the absence of the 3rd party means we have to PM then I will. I don't think it's necessary. We're talking about jetting. If someone gets their feelings hurt then it's related to something they shouldn't have said.

 

[Guest]

The carbs have 117 Main jets, 20 Pilot jets and 5DL36-3 Needles clipped to the third slot.

 

[Guest]

Why are they all so clueless?
Every Jap bike over 250ccs for the last forty years has been faster, you'd think they would know this by now.
Oh, well. entertainment for us.
Congrats.

You're exaggerating again.

 

[Guest]

I love the 78 GS1000E.

Nice bike Oldvet!!!

 

[KEITH KRAUSE]

The carbs have 117 Main jets, 20 Pilot jets and 5DL36 Needles clipped to the third slot.

OK. You're lean. Very lean to be exact. With a quality pipe and K&N pods, you would possibly hole a piston if this bike went on a long ride, especially if it was hot out. Yes, there are exceptions to anything but I only refer to the extent of damage. I'm no constant racer/hard on my bike but if my bike was jetted as yours I would see engine damage on one of my typical rides through the canyons and it wouldn't have to be hot out but that would be the straw that breaks it. You are doing damage though, simply because the mixture also cools your air cooled engine and you're not getting that right now.
Most of the time you're on the jet needle, though that doesn't make the main and pilot circuits any less important. I believe you have the stock jet needle? The factory jet needle position is #3 (the middle on a stock needle). Why would anyone leave the needle in the factory position if they've changed to pipe/pods?? Someone who claims to understand carburetion shouldn't make this mistake. Did he even ask you? You'll need to go to position 4 1/2 if using the stock needle, possibly position 5, if the stock needle can be made to work at all. Many times it just doesn't work well and the DJ needle is needed due to it's different shape. Many here say the jet kit made things easier and the bike ran better, myself included.
Main jet. You say you have 117. I assume maybe you mean 117.5? There are no 117 Mikuni's. Maybe another brand? You need 130 Mikuni mains or DJ 138 (same size, just different sizing/numbering methods). A 138 is supplied by DJ in their stage 3 kits just for an example. The other is 142 if the 138 isn't rich enough. You'll want the 138. Unless there's something wrong with your engine tuning (excessive retarded timing, etc) or some condition that's creating a compensating effect, I can't see how it can run reasonably well with a main jet that small. It would still run too hot even with the timing too retarded. Often you get some pinging on uphills, stuff like that when running lean. It certainly explains SOME of your 52 MPG though. The jet needle explains the rest.
Pilot jet. 20 is too rich actually. You say your plugs look good, though you don't say exactly their coloring. I'll bet they're white but when you slow down and are at minimal throttle positions before shutting off, the rich pilot circuit adds some color to the plugs, giving you a false read. A 17.5 is the largest you need for your mods. Tinkering with the fine tuning pilot fuel screws will be needed. Typical stage 3 kits actually recommend to retain the stock 15 if you're running their jet needle. With a stock needle, I always suggest trying the stock 15 with richer pilot fuel screw adjustments first. If you can't dial it in, then go to 17.5.
Questions.....were the carbs synched with a vacuum tool? This is part of jetting. You MUST synch the carbs on your bike, not some test bike, if that's the case here. There are no "bolt on" carbs. They require vacuum synching and at least some fine tuning of the pilot fuel and side air screws. In your case, they also require a complete re-jet.

 

[TheCafeKid]

Wired George eh?? Id be ripping those carbs off there lickety split and getting them rejetted...that guy....dont get me started..

 

[Guest]

So I take it I need a DJ stage 3 kit and 4 #15 pilot jets. I'm guessing that melt down in the mountain traffic jam had more to do with the carbs than stop and go traffic. I lost 1.5 quarts of oil during that episode. It seems I go one step forward and two back lately. I also guess pinging kind of sounds like little bits of gravel rattling around in the cylinder head on hard acceleration up the mountain. I don't think I was meant to ride much this year. I guess this is the forced excuse I need to dig into one of the other motors, and change it when I finally get the carbs sorted out. Any advice on the best place to get the parts? Would this present build have worked on a stock setup?

 

[KEITH KRAUSE]

So I take it I need a DJ stage 3 kit and 4 #15 pilot jets. I'm guessing that melt down in the mountain traffic jam had more to do with the carbs than stop and go traffic. I lost 1.5 quarts of oil during that episode. It seems I go one step forward and two back lately. I also guess pinging kind of sounds like little bits of gravel rattling around in the cylinder head on hard acceleration up the mountain. I don't think I was meant to ride much this year. I guess this is the forced excuse I need to dig into one of the other motors, and change it when I finally get the carbs sorted out. Any advice on the best place to get the parts? Would this present build have worked on a stock setup?

Your way of describing pinging sounds right. It's not near as loud as a typical car motor and not as "deep" but it sounds like you're pinging. Classic lean condition, though poor timing can sometimes lead to pinging, I'm pretty sure yours is mixture related. Pinging is always at its worst when the engine is under heavier load. Other things that happen when running lean is you'll get "spitting" out of the pods. Most often at low to mid/steady speeds and colder outside temps. Your 20 pilot jets may have helped to compensate, though compensation jetting always leads to other problems. Surging is the classic lean sign. The motor never seems to be happy at various rpm's. Steady cruising makes it easier to feel. Fantastic gas mileage is another sure sign.
A stage 3 DJ kit is a good idea. I help lots of members here try to make the stock needle/separate jets thing work but I always recommend the kit. Some members say they can't afford it so we give it a shot. Some say they're happy while others finally go for the kit. Truthfully, many owners don't know what a properly tuned/jetted bike feels like so if it just runs decent they're happy. So I'm not sure how many of the owners who went with the stock needle are a good gauge.
I haven't bought a kit for a long time so I'm not sure where the best place is to buy.
Your present set up wouldn't work for a totally stock bike either. Your jet needle position could stay as is because that's the factory position. The "3" at the end of the number you provided is the factory e-clip position. Your main jet would need to be 95. Your pilots would have to go back to 15 and be sure to order the correct length (there are 2 lengths of Mikuni pilot jets for your carbs).
You would then probably need to tinker with the pilot fuel screws a bit, and then adjust the side air screws for best rpm. Then vacuum synch.
Finally, with pods, you remove the 2 floatbowl vent lines and leave the ports open. But with stock intake, replace the vent lines and be sure they're routed under the seat and never kinked.
There are of course other items that may need to be done since I can't be sure of the work you had done. Float levels. Manifold condition/manifold o-ring condition, etc. Valve clearances. Ignition timing. Compression.
We can help you do the work. Many members may live near you and can show you how or help with tools. We're a good lot here.
Some people provide a service and that's great, but I don't like it when the truth is stretched to try to get that business. You trusted someone and all I can say is you didn't get what you really thought you were getting. What I've typed here is true. I can help you later if you want to get this bike jetted right. But you need good compression. That's a basic tuning necessity.

 

[Guest]

I have two more motors, one is a 3,800 Mi. motor, that should be in, or can be put in top condition quickly, but I'd really like to leave it on the '79. The other crated motor is an unknown. A friend gave it to me. It was supposed to have been built to run at Bonneville, but who knows. That is the one I'm going to look at first. It needs the left cover, and a starter. It can have the parts, and the Dyna S ignition off this motor. I knew this one had some problems, but was hoping to get through the winter with it. It has been lean since I got it with the old carbs, and yes it does spit back as you described, with the old and new carbs. I'm having a hard time believing the new carbs got built the way they did, it doesn't make any sense. It sure ran nicely though, and I was loving the mileage. I'm retiring this motor until I can get around to replacing the top end, maybe from an 1100. With the pinging that has been going on for a long time and the melt down on the mountain, I'm sure it needs it. I really didn't know what the pinging was until I put it together, thinking about what you have been telling me. I will certainly look you up for the carb tuning When I have one of these motors checked out for valve adjustment and compression. I guess this will also give me time to get the painting done.

 

[Guest]

The carbs have 117 Main jets, 20 Pilot jets and 5DL36-3 Needles clipped to the third slot.

Holy crap! You are way lean. Your overheating problem is probably your carbs.

 

[Guest]

Any advice on the best place to get the parts? Would this present build have worked on a stock setup?

I'm pretty sure I have some #15 pilots. I'll dig through my stuff in the morning and let you know. You can have them for free.

 

[KEITH KRAUSE]

OK Vet. Just let us know and we can help you get it jetted. VM carbs are easy to work on if you take your time and ask any questions first.
PS: way to go Bruce on the pilot jets. You da man!

 

[Guest]

Thanks guys, this has been an interesting experience. After wasting a riding season waiting for the carbs, and dropping a hefty chunk of change, I feel like they should be sent back for proper jetting. I don't know if that is going to happen, you all seem to have had experience with him. My local Suzuki shop confirms everything you have said. I really don't want to drop another $136.00 on a jetting kit I already theoretically paid for. Will I just be beating my head against a wall, or is there a chance he might make it right? I just want to ride before I'm too old to enjoy it ( I'll be 62 tomorrow), and I'm certainly not going to wait another three or four months to do it. I don't mind winter riding as long as there is no snow or ice. Thanks for the offer Bruce, would you PM me about the pilot jets.

 

[Guest]

Thanks guys, this has been an interesting experience. After wasting a riding season waiting for the carbs, and dropping a hefty chunk of change, I feel like they should be sent back for proper jetting. I don't know if that is going to happen, you all seem to have had experience with him. My local Suzuki shop confirms everything you have said. I really don't want to drop another $136.00 on a jetting kit I already theoretically paid for. Will I just be beating my head against a wall, or is there a chance he might make it right? I just want to ride before I'm too old to enjoy it ( I'll be 62 tomorrow), and I'm certainly not going to wait another three or four months to do it. I don't mind winter riding as long as there is no snow or ice. Thanks for the offer Bruce, would you PM me about the pilot jets.

I'd call wired george and tell him to at least give you $136.00 back. I'd say that's the least he could do considering his jetting could have destroyed your engine. That way you can buy a jet kit and do it right. We can step you through it, no problem. I found those pilot jets...I'll PM you for your address.

Oh, and happy birthday!! :dancing:

 

[KEITH KRAUSE]

Thanks guys, this has been an interesting experience. After wasting a riding season waiting for the carbs, and dropping a hefty chunk of change, I feel like they should be sent back for proper jetting. I don't know if that is going to happen, you all seem to have had experience with him. My local Suzuki shop confirms everything you have said. I really don't want to drop another $136.00 on a jetting kit I already theoretically paid for. Will I just be beating my head against a wall, or is there a chance he might make it right?

First of all, happy birthday!
I can only assume George did a good job of cleaning AND installing all new inner o-rings(?) AND adjusting the floats AND replacing any suspect part he found. If so, you got part of what you paid for.
I'm not here to argue with him should he chime in. He knows where he stands with me. I personally have little doubt he cleans the carbs and inspects for obvious problems. But after several experiences others have shared and my own personal discussions with him in the past, I believe he doesn't replace ALL inner o-rings, EVERY job. I also believe he replaces some suspect parts with used parts that pass his "visual" inspection. I could go on.
I just don't believe he does the complete job he states. He claims to make them "bolt on" but he really isn't satisfying that. He even claims he vacuum synchs them on HIS test bike. If he does, he's wasting his time because you can only synch them accurately on YOUR bike. I don't think he's that dumb. I think the synch thing is another part of his advertisement to make his service sound good to customers who just don't want to mess with carbs. Carbs, like electrical, can intimidate many owners. His business thrives on that. He makes you think you won't even need a carb vacuum tool. You'll save more money. But he knows if he told you they must be synched, then maybe you'll try it yourself. Heck, maybe you'll just do the whole thing! He doesn't want that.
As for jetting, he has fooled even me to some extent because I once believed he knew more about the subject. He's had some experience in other areas and I thought if he does this carb business then he must have picked up some good knowledge along the way. Obviously not.
He should've told you a stage 3 kit would be a wise investment instead of his "custom" jetting...but like many other things, maybe he doesn't even know the DJ kit works or exists.
I think he did part of what you paid for but I understand you're being ticked about this. Now, he can claim his jetting is correct and even show up here and argue with me/us, or, he can change the jetting to what makes sense and not charge you for the extra jetting or shipping. If he does the latter then at least he's trying. However, I'd ask what re-jetting adjustments he plans on before just accepting it. You can verify it with us, providing you trust us, which I think you do now.
I'll be back in a few. Don't want to push the time limit here and maybe lose things.

 

[KEITH KRAUSE]

Back again. I was thinking about replying even before your last post but figured you'd post here if you wanted to continue. I thought maybe you'd given up on riding this year. If you didn't, and I can see you haven't, I wanted to offer some help on the jetting that could at least make things better and allow you to get through the year. Not necessarily perfect jetting, but much better than what you have now and better for the bike.
I'm no fan of jetting a bike that has other tuning issues, especially poor compression as you state. Poor compression simply doesn't allow proper combustion. Combustion and jetting are one. Known proper jetting on a well tuned bike can have different results on a bike with tuning problems. You can't blame the jetting in these cases.
Because I can see you just want to ride awhile longer and deal with this later, I can suggest some better jetting, similar to what works on other bikes like yours. Because I have no way of knowing what other tuning/maintenance may be needed on your bike, I can only say that my suggestion should make things better but I don't consider it my final jetting. I just want to make your bike run so it's not so lean. It may still be lean but not nearly as much. I also don't want to go too far and make you run rich. Your poor compression really complicates trying to avoid going too rich. Normally, you always error on the rich side so to speak. A little richer is better than a little leaner in most cases. In your case, richer may result in serious issues like unburned fuel/backfiring, plug fouling and very poor mileage. So my idea is to richen you up so you're not so lean. You may still get lean related issues, some obvious, some not, but you'll be better off and have much less chance of running so hot as you have.
Also, I may be wrong but it seems to me that you may not want to deal with any re-jet issues that turn into a trial and error thing that requires you to get too deep into this. I'm offering a "band-aid" fix for now. I would fully expect it to run better and I KNOW it will be closer to the correct fuel/air ratio though not final. I don't mean to go on and on but I just want to say this stuff is important to me and it's really a temporary suggestion. If your bike started acting up and gave you more trouble, then it's because of the overall condition of your bike, not the re-jetting.
I suggest the DJ kit. Even this kit can have minor issues. DJ says that. Some bikes performance varies. However, issues are generally tunable to the point that they are minor. You can't expect perfection at every point. I still get a "spit" or two on colder mornings as we've talked about before. I fine tuned mine until I reached the point where any further attempts to richen it resulted in worse issues on the rich side. It happens. I tried a 17.5 pilot jet and it worsened things. The DJ needle really does work better with the stock 15 PJ. My bike runs great but I suppose it's not perfect in every way. If you go with the kit there's a limited adjustment that has worked well on most bikes here. We'll help you with that if you do. You can't expext to get it right the first try but many times it does work out that way.
If you go with the stock jet needle for now then I can help.
Main jet. I flinch a little here because of your compression. Part of me wants to say to settle for some 125's or 127.5's to avoid a rich possibility. I KNOW a properly tuned 1000 with your parts runs great on a 138 DJ main that's approx' the same as a 130 Mikuni. I also don't want you to waste money. Normally, 130 is it. It might be wise to go with a 127.5 in your case. It would be way closer to what works best than your 117.
Jet needle. Normally, if the stock needle can be made to work, a minimum 1 1/2 positions richer is needed (position 4 1/2), sometimes the bottom (5th) position is needed. I want to say position 4 1/2 in your case but again, I'm worried it will end up rich. Richening your current needle position by only 1 position is still lean from my experience but it would be a significant change for the better and make you less lean. You'd run MUCH less hot. Position 4 1/2 would also require you to get some jetting spacers to make the 1/2 position change (provided in the DJ kit). Position 4 can be made simply by moving the e-clip. Up to you here. Play it safe(?) and go position 4 but understand it's still on the lean side or try richer?
Pilot jet. Your 20's won't work, with or without a future jet kit. The stock 15 (in combo with a stock jet needle) will be on the lean side more often than not. Richer pilot fuel screws can sometimes be enough to assist the stock PJ but don't count on it. Testing is always required. If it doesn't work, then you get a 17.5 PJ. I suggest for now, go with the 15's and richen the PJ screws to 1 1/2 initially. Test. Fine tuning will probably be needed so there's no way around it. If the 15's are still lean, it shouldn't be seriously lean. You may get some minor issues but nothing that's damaging your motor.
After the above changes you MUST do the following or the jetting will be compromised.
Remove the 2 floatbowl vent lines. Leave the ports open.
Initially, adjust the side air screws to 1 3/4 turns out from lightly seated. You will need to adjust them using the highest rpm method to be accurate. 1 3/4 in in "the ballpark" but can't be considered correct for your bike. Do you know how?
Vacuum synch. Assuming the slides were properly bench synched, this shouldn't be difficult. However, poor/uneven compression can make synching nearly impossible.
After this, your bike should run much better and closer to how it should run. Yes, mileage will drop some. How much I can't say but normal loss is 3-4 MPG (from stock) on a well tuned bike. The pinging should be at least lessened. The motor not nearly so hot.
Let us know what you want to do. Hope things work out well. If you wish, do the work yourself. We can help. Carbs are a bit spooky ar first but if you allow us to step you through before you do something wrong, it comes out well. You just need patience and good fitting tools to take apart the carbs. Jet changes are easy. Only the jet needle has to be handled with more care. The bench synch is easy. I have detailed info on how at this site. The vacuum tool synch can be learned or shown to you buy a nearby member(?).
Now, I'm off to the turkey! Happy Thanksgiving!