Where are the numbers on my mains?

[scoobers]

Hello, I've been wrenching "small" engines for 10+ years so I'm not new at this, rebuilt many a Mik as well as Walboros and Tillotsons (OLD Arctic Cats) but never have I not been able to find the numbers, or whats left of them, on a set of jets. I have a '79 GS750 and a '78 GS1000 and I can't seem to find a number, symbol, or any markings on any of the main jets from either bike. Pilots are all 15's tho. Am I missing something here? Where are the numbers?

Thank you for any ideas/guesses.
Scoobers

[KEITH KRAUSE]

The number is right at the opening of the jet. Mikuni jets have a symbol next to the number. Looks like a box in the corner of a larger box. '78/'79 GS1000 stock main jet size is #95. Pilot is #15.

[KEITH KRAUSE]

Oh, and your 750 should have 102.5 main jets. Same pilots.

[scoobers]

jet number

Tkanks Keith. I still can't find it. Is it under the extender? on the side? top or bottom( as it is in carb on bike)? I've got them in my hand and have looked under 30x magnification and still cannot find it. I unscrewed extender and looked there too. No luck. I know the box in box and can't find that either. Oh and thanks for saving me from searching for proper jet size. That was next after i figured out what is in them now!!

[KEITH KRAUSE]

The number is right next to the opening. Where the fuel first enters the jet.
If you have no number, I don't know why. I'd toss them and get some jets that you know are the size you want and haven't been tampered with.

[SqDancerLynn1]

You need a strong magnifying glass. If the jets are tarnished it will be hard to read

[scoobers]

got em

I ran a Dremel with a brass wheel over the jets and could see the Mikuni symbol and what looks like a 100 on 1 jet from my 1000.(it has pods only)
Thanks for the replies
Scoobers

[KEITH KRAUSE]

I ran a Dremel with a brass wheel over the jets and could see the Mikuni symbol and what looks like a 100 on 1 jet from my 1000.(it has pods only)
Thanks for the replies
Scoobers

OK. But if you have 100 mains, that's not enough of an increase for pods. In my opinion.

[scoobers]

Thanks for the return PM Keith. It is running a bit lean on two cyls. I imagine the other two carbs have some junk in 'em again. I thought my 750 tank was clean but it isn't (saw rust in gas line) and no filter either. Guess I'll acid wash that tank too. My prob is I don't really know what all the PO did to my old '78 GS1000. Just a brief history: My mom got it 13 years ago as a B-day present and never got to ride it. Her then fiance couldn't keep it running more tha a minute or two. She's no longer with me in flesh, only in spirit so I really appreciate any help I get unravelling the mysteries that this bike holds. I could have just jumped on my 750 and been happy but this 1000 means so much more to me than just a fun old bike to ride. I'll be riding it for and with my Mom. It had sat in a shed with zero attention for 10 of those 13 years. Three weeks of work and it's a much happier bike now. Everything works again. I did find bad O-rings on the intake boots. All of the rings look pretty dry rotted and useless. I am replacing the intake boots really soon here anyway cuz they are a bit cracked and seperating at the base also. I figure a fresh start is a good place to start!! Can I use the afrtermarket Mikuni rubber flanges on Bike Bandit or Dennis Kirk or is OEM mandatory? Also is there a way I can tell if the pipes are stock? They are a bit different looking into the end than my stock pipes on my 750 look but I don't know if that is a good comparison! Either way what jets would you start with for pods only and for pods w/pipes? 120? 125? I know I could probably search for it but I wanted to get back to you without the PM's, and by the way thanks for taking the time to read our posts and reply to them. Reading and replying must take up a lot of your time, but you do it anyway, and for that I think we are all gratefull. I know I am.

[KEITH KRAUSE]

Got in late tonight but thought I'd try to help a bit more.
I'm not familiar with the Bikebandit or Dennis Kirk manifolds, so I can't say anything about their quality.
I do know that a manifold is very important and I've always bought genuine Suzuki manifolds. That's my choice.
As for what exhaust you have, can you post a pic?
As for jetting suggestions, what brand pods do you have? I also need better exhaust info and hopefully the pic.
Are you asking for jetting suggestions on the 1000 only?
Remember, before re-jetting, you need to be sure of some basic maintenance. This means the carbs should be clean and all inner o-rings replaced. Robert Barr sells o-ring kits. The floats levels need to be set correctly. The carbs must be bench synched and then should be vacuum tool synched afterwards. Replacing the manifold o-rings and possibly any hardened/cracking manifolds is a must.
The ignition must be timed correctly and the points cleaned and their dwell set, if you have the stock points. All electrical connections must be checked/cleaned at the coils, plug caps, battery, etc.
Cylinder compression must be within specs.
Valve clearances should be checked/adjusted correctly.
It's a lot of work and I'm not sure what you've done yet, but this stuff needs to be checked first and then the re-jet will be less trouble. If you skip some of this stuff, you may end up mixing trouble shooting with jetting.
A bike sitting for that many years will require all or most of the above.
Let us see a pic of the exhaust and include any other problems you notice at this time.

[scoobers]

Ok . Carbs were clean till I rested my 750 tank on my 1000 while I acid washed the 1000's tank and unknowingly added a little rust to my carbs, I'm re-cleaning them after I make this post. I did bench sync them. Getting vac tool on Fri. I am only asking about Jetting the 1000. The 750 is running better than the day I drove away from the dealer (clean carbs). All I know about the pods is that they were made In Australia. I will likley replace them with something out of the parts unlimited catalog. I already replaced and oiled their foam. As for exhaust I can post pic just tell me at what angle(s). I did clean points and time it. I'll recheck dwell. Electrics, compression, and valves are all good, Float levels are all ok. Oh, and I picked up a free flow fuel filter too! Just in case. The intake flanges I am referring too are Mikuni parts, solid rubber. same diameter, bolt hole spacing, and depth. I think about the only difference is that they don't have the suzuki "S" on them and they are about thirteen bucks cheaper each. Two of the intakes I took off had neither the Suzuki "S" or any sign of a Mikuni logo, no idea what they were. I'll have to recheck plugs after replacing the intakes to see if air leaks was causing my lean condition. I don't know, maybe the owner from years ago had thing set up right. On the jets all I can make out for certain is a one and the Mik logo on one main only. As always thanks for the help, and hey, I'm not in any rush so take your time, don't stay up late for me,(unless you want to) I'll still be here in a couple days. I appreciate your help whenever you can give it.

[KEITH KRAUSE]

A fairly close shot of the exhaust from the side and rear angle should be enough to determine if it's stock or something else. Is the exhaust loud?
It sounds like I can assume your foam pods are going to be tossed? I'm guessing you'll buy some "Emgo" type, wire mesh pods? Just make a choice and stay with it because changing the pods later may mean changing the jetting again and that's just more work.
Sounds like you're ready to jet, I hope. Be sure those float levels are set to .94"/95". I still suggest rebuilding the carbs inner o-rings complete. Ten years of sitting guarantees the o-rings are hard and at least somewhat shrunk. I only suggest these things out of experience. Jetting can be difficult enough with good parts. Tearing things apart again and troubleshooting is a pain. Time is money.
I also suggest against using a fuel filter. They're unnecessary because the petcock screening takes care of that. If you have any rust, the tank should be repaired right. Be sure to clean the gas cap vent if you haven't yet. Be sure the petcock is operating right. You'll also want to remove the two floatbowl vent lines. Leave the ports open.
As for jetting, I'll need those pics. There's been a few members lately using pods and stock exhaust and I've tried to help, but they don't come back to say how my/our suggestions worked. I have an idea though of where to start. Pods and stock exhaust aren't a good match as I've said in other posts. The majority of my experience is with pods and quality pipes and other mods. You can still get pods and stock exhaust re-jetted right, but you can't expect things to be done the first try. We'll see.
I also don't have much info on where the jetting may be now and how the bike ran at that point. Were the plugs dark or ? when you removed them? Did you notice any heavy carbon build up/exhaust stains anywhere?
The most work with these carbs is adjusting the jet needles. Disturbing the needles requires a new bench synch too. As a rule of thumb, even the cheapest pod filters require the jet needle e-clip to be lowered at least one position, which will raise the jet needle one position. With your stock exhaust(?), it's possible one position will work but I'd guess 1 1/2 positions richer would be a better bet. A "1/2" position is achieved by using a jetting spacer directly on top of the e-clip. The spacer is approx' .022" thick and can be found at Radio Shack or most hardware stores or if you know someone with left over jet kit spacers of that approx' thickness.
If your jet needles are factory set, their e-clips are in the 3rd position from the top. So 1 1/2 positions richer would mean placing the e-clip in the bottom (if stock needles) 5th position and placing the jetting spacer directly on top the e-clip. This would be position 4 1/2. If you can't locate jetting spacers, you have the choice of trying the clip in the bottom position or the 4th position. I believe the bottom would be too rich though. As always, trial and eror. All you can do is test at solid 1/3 throttle position and that will tell you what the needles are doing. Be sure to re-install the two factory plastic jet needle spacers in the correct order. Thicker one goes on top the e-clip/any jetting spacer, thinner goes under the clip.
If you don't remember where the clips are at you can always try testing as is and see what happens. Do what the plugs/performance say.
As for mains and any pilot circuit changes, I'll wait to hear about the exhaust. It would also help a little to know if you're going to go with those Emgo type pods as I'm assuming right now. Some shops have a good main jet supply and will let you swap mains if you don't nick them up. Some don't.
I've been working late all week and I'll be working Saturday and then (weather permitting), going riding Sunday. But if you're starting the re-jet this weekend I'll try to check in to see that pic and give some help about the mains. You may have to order the main jets (or Robert Barrs o-ring kits?) and wait anyway? Just don't cut corners and try to hurry. Others here may help too.
I know all about being sentimental over a bike. That's how I am with my '791000E. I've had it since new and it's part of the family.
Check my profile and visit my website if you're interested. I've put a lot of work into my bike.
Talk to you later.

[scoobers]

Yes the exhaust is loud. Well a lot louder than my 750 is anyway. Not loud like a hog. My two are the only gs's I've ever heard. Since I fixed my intake leaks the plugs look a nice tan color. Not the white ashy color they were. I rode it around and chopped throttle and checked plugs at several throttle positions, all ok except idle. Idle is still lean. I'm now thinking I might keep the foam filters and just go with bigger pilots as my screws are almost four full turns out! I still do not know what size mains it has, they are all to dinged and pitted on the ends, nor do I know what position the needles are in. Oh and there is no screen on the petcock of the 750 tank, but there is on the 1000's tank. It's on my to do list. And like I said it's not the paper cone but a fine mesh free flow filter, at least till it catches too much junk like the one on my snowmobile did. It took four years tho! It's only gonna be on there till I finish the tank that belongs and fits on it. I'm busy all day now working on a large farm. My only time now is usually weekends. Funny how I earned a degree in electronics, worked for Lucent/Agere and after 8 years wind up on a farm for a little while. I noticed your an electrician, You with the IBEW? I was local 1522. Black Beauty is VERY nice. You were not kidding when you said you did a lot of work and spent a boatload of cash on her. Nice polishing. Nice everything. One day I would like to take the time and money to make my 1000 look half as good. Any more than half and I would have to retire it or go somewhere else to ride it. These dirt roads with "manholes" in them eat anything on wheels right up. I live in a rather rural area with poor road maintainence. You could lose an Omni in some of these holes! Just by looking through your pics I can tell you have been very, very nice to her, and noting that you did a complete restoration after 106K she must still be very nice to you. I'll ride mine till it dies, then resuscitate it and ride it some more. I love both of those bikes. Anyway I'm tired and I'll try to get those pics up this weekend after I check needle positions just to know where they are at. So far I'm getting lucky. Thanks Keith. I'll let you know what I find and where I want to go with it this weekend. It runs great and has all kinds of power after it warms up a bit, takes about 3 minutes, I'm happy with whatever the PO did and what I've done thus far just to get her running decent. Is it worth the time and cost to go to Emgo's? At this point I'm ready to fix the idle circuit and ride it after I put it all back the way it should be. I'll post a pic of the plugs too while I'm at it.

Enjoy your ride,
Scoobers

[KEITH KRAUSE]

Thanks for the compliment on my bike. Yes, I'm with local 18.
If your plug tests show tan plugs at the different throttle positions, I'd leave the jetting be then.
I don't recommend Emgo pods, but that's just me. I see no reason to go from your foam "Uni type" pods to wire mesh, unless the foam is deteriorating.
Sounds like the only jetting issue you have is the pilot circuit. The bike warms up kind of slow and has light/whitish plugs. Since you say the carbs are clean, I'll assume it's jetted too lean then. I also doubt that a PO could have tightened all four pilot fuel screws (underneath) too tightly and broken off their tips, though that's possible. You would know(?), having cleaned the carbs. Four turns out is beyond their range of assistance to the pilot jet.
Be sure the side air screws aren't too far out though. They must be adjusted for highest/best idle, using 1,000 rpm as a base point.
If you still have the stock #15 pilots, then I'd try 17.5 and put the pilot fuel screws back to about 1 1/4 to 1 1/2 turns and test. Be sure to buy the correct length/design of pilot jet. There are two lengths/similar types from Mikuni. Get the right ones, take one with you if you go to a shop to order.