Rebuilding a new set of George's "REBUILT" Carburetors

[OldVet66]

Instead of dredging up the old post, I'm starting a new one. The old thread is: http://www.thegsresources.com/_forum...d.php?t=151286. To make a long story short, I wasted an entire riding season waiting for and spent $440.00 to learn the lesson that I need to learn to rebuild my own carburetors. The set I paid for that was supposed to be built for a GS1000E with 4 into 1 pipes and K&N pods. I was impressed at first with 52MPG until they left me on the mountain in slow traffic, on a 30 degree night, with a seriously overheated motor. After a long cool down and when traffic cleared hours later, I got it started again and limped home. Thanks to Help on the forum I learned there are no bolt on carburetors no matter what the claims are about test bikes. After a hard winter, I finally ordered a DJ Stage 3 jet kit, and thanks to "renobruce", who sent me the proper pilot jets , I'm ready to start the rebuild of the rebuild. I need a little help with the initial setup. Hopefully "KEITH KRAUSE" will chime in and help with the initial setup. The DJ instructions are ok, but the pictures of the carburetors they refer to are not clear at all.

[Billy Ricks]

If you use DJ's recommended settings and install the pilots from Bruce you'll be very close right from the start.

Other people have had not so nice things to say about George. At one time he was a member here. Rode with him once on one our our Hill Country rides here in Texas. The guy seemed pretty full of himself.

[OldVet66]

I don't know if it's "himself" he's full of but it's not expertise in building carburetors for GS motorcycles.

[KEITH KRAUSE]

If you use DJ's recommended settings and install the pilots from Bruce you'll be very close right from the start.

Other people have had not so nice things to say about George. At one time he was a member here. Rode with him once on one our our Hill Country rides here in Texas. The guy seemed pretty full of himself.

Billy, not so about the base settings DJ gives, at least for the VM equipped models. The jet needle position they suggest is way too lean.

[KEITH KRAUSE]

OldVet66, I'm just glad you mentioned the great mileage you were getting in that thread. I knew it wasn't right to get that much so I chimed in. When I saw George's name pop up, I knew you'd been taken in by his BS.
Very easy to have happen. Carbs can be quite a mystery to some and when you see a guy claim he does excellent work and even synchs/jets them on his "test bike" (which of course is EXACTLY like yours) so they're "bolt on", I can see the attraction.
He obviously knows little about jetting and certainly never did actual testing.
Then to say you can vacuum synch the carbs on a test bike and the vacuum levels will then stay as set when you install those carbs on your bike is beyond stupid. What gets me even more than that stupidity is I truly believe he's just lying and NEVER does this so-called synch and therefore is a fraud. I also believe his rebuilds are not thorough and only involves a cleaning and fixing something that he knows must be fixed to avoid customer problems. He makes it sound like you're getting back these 1000% perfect carbs in every way.
He came around here once to draw business and I called him out and reamed him a new one after he wanted to fight over his statements. He left and I'm glad that at least some owners were spared his BS. To tell you the truth, I'd kick his fat arse if I ever had the chance. That's how much he ticked me off.

[OldVet66]

I installed the DJ stage 3 kit today. What a difference! You are entirely right about George. He is not selling a product as advertised. The number 4 slide had 4 or five notches on the bottom of the slide where someone had used what looked like a screwdriver to knock it free I guess. The notches looked like what you would do to mark the rim around an adjustment screw for a reference mark. It was rough as hell and we had to file the beveled edge smooth. It was obviously synced for his test bike, or maybe not synced at all, 3 and 4 were fairly even on the air box side of the carbs, 2 had a larger gap and 1 was opened more yet. He used the wrong O-rings on the pilot fuel screws. They were too fat, and all were damaged when removing the screws. He didn't bother to change the gaskets on the tops of the carbs. It appears he did a good job of cleaning where I could see. It looks like he soda blasted the insides. His bead blasting on the outside sucked. It looks like all the beads were shattered and he was using the media way beyond it's intended use. I had bead blasted my brake calipers with new fine beads, and compared to mine, his looks like sand blasting. I just adjusted the slides to match the smallest gap, used your initial settings and bolted them on the old motor. It started beautifully, choke response is 150% better, than before. I don't intend to do things properly with this on the old motor. I just want to get it running well enough to ride until I get the new motor checked out. That will give me time to save and purchase a Morgan manometer and a few other tools I need. I got thoroughly ripped for $440.00 and a riding season. The bike is a totally different beast now. Much quieter with low and mid range much stronger. It takes very little throttle twist to get up to highway speed, and I don't have to open the throttle near as much to cruise at 60-70 MPH. It used to work on my wrist to maintain cruising speed, now it seems I'm barely opening the throttle to maintain speed. It does do a muted popping on deceleration, as you said, and no more spitting through the pods. It does want to bog at full throttle when I want to roll on in fifth gear, but if I keep it under 3/4 throttle it runs great. I will check the float levels when they come off for the new motor. Any suggestions would be appreciated. It is really good enough to commute to work now, but I would like to have the top end for the occasional rude SUV and Pickup Truck that wants a ride on the back of my seat without asking.

[mike10]

Thank God I didn't

I almost sent my carbs to George. His Add is good, if you knew nothing about carbs like me it sounded like a safe way to go. Thanks to this site I did it all myself. Saved money, and now I know a few things about carbs. I really enjoyed working on them. I had a problem with the Air Screws too. But someone here told me to use something that removes paint and a good screw driver. Out they came.

[KEITH KRAUSE]

I almost sent my carbs to George. His Add is good, if you knew nothing about carbs like me it sounded like a safe way to go. Thanks to this site I did it all myself. Saved money, and now I know a few things about carbs. I really enjoyed working on them. I had a problem with the Air Screws too. But someone here told me to use something that removes paint and a good screw driver. Out they came.

There ya go! That's why this site is so great.

[KEITH KRAUSE]

Sounds good except the 5th gear roll on bog.
No offense, but it's hard to know if it's bogging too easily or if your use of the throttle and tranny, or the "old motor" have something to do with it.
The pods/pipe/jetting is designed to improve higher rpm/wider throttle openings. There IS some minor loss of torque (or delay if you like) when rolling on as you describe, but it isn't anything that would be a true bogging condition and we're talking about a couple pounds of torque. Overall, the performance is better in most opinions and certainly when you want to accelerate the hardest.
In 5th gear, you should be at approx' 4K rpm (65+mph)to do a full roll on and expect clean acceleration (and it will accelerate strong). Less than that simply isn't the way to make this bike accelerate. It would bog at least momentarily if opened up at lower speeds or greater loads.
If it WERE jetting related, I can tell you that the 138 main jet is NOT the cause. The supplied 142 sometimes works on certain bikes but can cause a roll on bog unless you start at a good 6-7K rpm first which tells you the 142 is just too big. Believe me, the 138 mains are not the cause.
The jet needles set at the 4th position are also not likely the cause here. They effect approx' 1/5 to 3/4 throttle position but can have some "overlap" effect with the main if set too rich. Because you say that "3/4" roll ons are good tells me it isn't the jet needles. It could be possible, but VERY unlikely, that the needles are 1/2 position too rich here. Only if you had something wrong with your bike that had a "richening" effect such as poor compression/combustion do I think the needles would work best at a leaner position 3 1/2. That would require compensation jetting and that never works well.
The pilot circuit, if anything, keeps the stock 15 jet and only excessive pilot fuel/incorrect air screw adjustments could cause a richness problem, and then they would have little/no effect on your roll ons.
So I doubt the jets or needle are to blame. The decel' popping, to a point, is normal and can be expected and screw adjustments can help there.
I think you may be opening it too soon and creating a bog? If it truly is bogging at a point/under conditions where it shouldn't, then I would FIRST be sure the bike has GOOD/UNIFORM COMPRESSION within specs' and is tuned. The valve clearances and ignition timing/advance must be correct. After that is done, you must vacuum synch with a vacuum tool. Clean acceleration depends on reasonably uniform vacuum at all carbs. It's a part of jetting many ignore simply because they don't have the tool or don't know how. In my opinion, you can't get accurate plug reads or judge the performance until this is done.
Then there are the carbs themselves. Float levels must be checked. .94/.95" is right in the middle of the factory range. Set them there and if careful, it gives you that slight margin for error since the factory states these carbs will work right if the levels are anywhere between .90 and .98". Setting them in the middle also allows for some float valve wear/spring wear as time goes by. You also need good inner o-rings or you will have jetting issues. I mention that because you noted issues with yours. I can only assume everything else is right inside per your inspection.
If you really do have a bog that's not caused by poor throttle use, then you should do those things. If it's still there (I doubt it) then let us know and we can work on it.
PS: if you're judging the bike on how it rolled on before, keep in mind that lean mixtures actually can improve acceleration to a point. With jetting that's correct, the bike may perform differently than what you expect. Wish I could ride it myself. That would tell me in a second. Again, I'd be surprised if the jetting is the cause.

[Billy Ricks]

Billy, not so about the base settings DJ gives, at least for the VM equipped models. The jet needle position they suggest is way too lean.

They are usually close with CVs. I haven't had any experience with the VMs.

[OldVet66]

Keith, I'm sure this motor is toast after the severe overheating. It may have burnt valves and low compression. It uses a lot of oil after the melt down that George said was impossible because of his carb build. This is why I don't want to put much effort into trying to get it perfect. I'll save that for the new motor and do it right. This exercise was to install the DJ 138 jets, needles, the # 15 pilot jets, replace the O-rings with the kit that I got and replace what was necessary. Having done that, I'll limp along until the new motor is thoroughly checked out. What size opening should I have on the air box side of the slides when properly benched? What I adjusted to, left the intake side of the slides at the top of the arc possibly a little more than 1/32" opened. I need to get a tool to adjust the pilot fuel screws without burning the crap out of myself. I have an old geared angled screwdriver attachment from my Electrician days, that ought to work nicely, if I can find it. It will hold standard trade screwdriver bits for drill motors (I'll fabricate a knob for the shaft to turn by hand). It'll have to be tune by ear until I can afford the Morgan carb tune. I was riding in the rain, so I'll have to check the exhaust on a clear day to see if I'm rolling black smoke on the roll on bog. I suspect it's a tad rich, but have been too busy at work to get time to pull the plugs, that had been burning mighty lean throughout all of this. The timing was set properly on the Dyna S ignition, so I don't think that is a factor. Even if I can't get this any better, it is more than adequate for driving like a civilized human being. Puts me to sleep just thinking about it.

[KEITH KRAUSE]

What size opening should I have on the air box side of the slides when properly benched? What I adjusted to, left the intake side of the slides at the top of the arc possibly a little more than 1/32" opened. I need to get a tool to adjust the pilot fuel screws without burning the crap out of myself. It'll have to be tune by ear until I can afford the Morgan carb tune. I was riding in the rain, so I'll have to check the exhaust on a clear day to see if I'm rolling black smoke on the roll on bog. I suspect it's a tad rich, but have been too busy at work to get time to pull the plugs, that had been burning mighty lean throughout all of this.

You adjust the slides to the lowest possible point. Turn slowly and you can see the slide bottom. AS SOON as it bottoms, stop turning. Turning a little more will actually begin lifting the other slides. Turn to bottom, stop. That simple. If you did it right they should all be uniform.
I have a detailed post on how to adjust not only the slides fully closed position, but also the fully open position that some don't know about. The thread was authored by "hoomgar" and the title is something like... "'78 GS1K rejet, bad fuel economy attn Keith Krause"? I believe post number 36? Big thread.
I just use a short screwdriver to access the pilot fuel screws.
I really doubt the bike will have dark exhaust showing during roll ons or any other time. I know these bikes and can assure you this jetting wouldn't cause any significant bogging. Now if you really do have that problem then I'm sure it's due to the motor in some way and not the jetting.
If the bogging bothers you enough then you could tinker with things but it would be compensation in my opinion and should only be used as a temporary "fix". Going by your exact description of the bog and how you minimized its effect, it would make sense to supply less fuel when the throttle is past 3/4, on the main jet. That would mean a smaller main obviously and shouldn't effect anything else. Without riding the bike I can only guess what would be needed. A 138 DJ main is nearly identical in size to a 130 Mikuni main. They have different ways of sizing their jets (cc's flowing vs actual hole size), hence the different numbering system.
You could invest in some 127.5 Mikuni's and that would be approx' 1 step leaner. That would lean it obviously. Enough, I can't say. Next step would be 125 and that would surprise me if needed but again, your motor or ? is creating this need.

PS: had a thought...did you adjust the side air screws for highest rpm?? If they are not adjusted correctly or their passages are semi-blocked, they will not atomize the fuel going into the jets properly, resulting in a "rich" condition. Also, did you remove the 2 floatbowl vent lines to improve bowl venting/fuel flow?

[OldVet66]

I got a chance to do a little tinkering yesterday. I got a set of vacuum gauges and adjusted for a uniform setting. got 1, 2 and 3 close, 4 didn't change, all the way closed or opened no change. Adjusted the side air screws for highest rpm, again very little change on number 4. while adjusting I saw a lot of blow by from the top vent tube. Changed the oil, and it looked like there were some metal flakes. Despite the slightly opened slides, it starts instantly, likes a good warm up or idle will fall off and stall. After it's warm, it isn't too bad. It rolls on hard in fifth from 3500 RPM. These motors must be next to indestructible. It will do until I get time to prep the new motor and do it right. It does still spit now and again since I've had more time to ride it. All together, though, it has tons more available power, sounds real good and is a pleasure to ride. .

[KEITH KRAUSE]

I got a chance to do a little tinkering yesterday. I got a set of vacuum gauges and adjusted for a uniform setting. got 1, 2 and 3 close, 4 didn't change, all the way closed or opened no change. Adjusted the side air screws for highest rpm, again very little change on number 4. while adjusting I saw a lot of blow by from the top vent tube. Changed the oil, and it looked like there were some metal flakes. Despite the slightly opened slides, it starts instantly, likes a good warm up or idle will fall off and stall. After it's warm, it isn't too bad. It rolls on hard in fifth from 3500 RPM. These motors must be next to indestructible. It will do until I get time to prep the new motor and do it right. It does still spit now and again since I've had more time to ride it. All together, though, it has tons more available power, sounds real good and is a pleasure to ride. .

OK. After you get the new motor done just ask if you have questions.
If I'm reading your post right, you couldn't adjust the vacuum at #4?? Not sure what you mean by "all the way closed or open" but hopefully any inability to adjust vacuum is related to a motor problem. When you did the bench synch you would see if the adjuster screw was working (raising/lowering the slide). Possible too that the vacuum tool was leaking at the manifold? Anyway, we can deal with that when ready to. Not sure about the blow by from the top crankcase breather hose. "Some" is normal. Shouldn't be a lot. Depends on trip length, etc.
As for some spitting, depends at what throttle position(s) it happens. Also, there's some overlap of the pilot and jet needle circuits so it could be either circuit. If pilot circuit related then you can try richening the pilot fuel screws a little and test for effect. If you decide to tinker with them some then keep a record of where they are now and any adjustments and you can always set them back if you get results you don't like. An additional extra 1/4 turn OUT might be a good starting point. If it's a little slow to warm up then that little extra at these screws could help that too. Spitting can also be related to the possible vacuum issue at #4 and/or motor condition too.
Good luck with it and let us know if we can help.

[OldVet66]

Thanks Keith. I meant that with the Pilot fuel screw seated or turned well passed your initial setup, there was no change, even though the gauge was reading quite differently from the other three cylinders. there are new O-rings on the spouts from the engine, and they are the better ones off the low mileage parts bike. The new ones are waiting for the new motor. Later, thanks again.