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

[Hoomgar]

Keith, you might as well speak Russian to me. I haven't a clue and have never done anything you just asked and don't know what most of it means. I will need to go through the docs in the garage. But time is a waisting now because alas, I am GS-less once more, again :x For the moment.

Well it's all bad. And down hill from here. As you can expect when purchasing a bike that is 27+ years old there are many "things" that are wrong or rigged or damaged. Here is the list as of what transpired tonight.

I went to put the plugs back in. Well plug 3 (the funny looking one) wouldn't thread in so I stopped. Looked in the hole with a light and it looks as if someone has cross threaded a plug in there at some point about 1/3 of the way down. I took my time and got it in correctly and it seemed to tighten up OK but now I know what that buzzing sound was the last couple days, a loose plug! It was all sooted up on the threads because of it.

Next, I figure we'll put the kabosh on that lawn tractor fuel filter. You know, the one they put on with clear lawn tractor fuel hose? :roll: Had to cut it off as that stuff is like Chinese finger cuffs and would not pull off.

So I put a good piece of fuel line on it, get all the plugs torqued, slap the tank on and go get gas. Coming back it is running really nice but I smell gas :? Yup, sure enough, pull over and look, it's peeing gas out like there is no tomorrow from the overflow tubes.

Apparently this was a precariously balanced system. The inline fuel filter was restricting enough fuel to keep that from happening or the minute I took it out some dirt instantly found it's way into one or more of the carbs and is clogging the needle valves.

Well, the carbs are out! On the bench and bowls off. What now?

In the mean time I will start on some of the things you just said.

Oil the air filters? This is new. What of that? Never heard that before.

[Hoomgar]

Hi Mark. Finally got some time.
First of all, buy the genuine Suzuki o-rings for the manifolds. Apply some hi-temp bearing grease to them. If you have the Phillips replaced with Allens, torque to 6 ft/lb.

I can do that, but it will take a while for them to come in.

I would use the carbs that already have the DJ kit.

Might as well do the ones on the bike now.

Now as for your bad gas mileage and us blaming it all on the carbs, you have to be reasonably sure the bike is ready to be re-jetted/synched.
Compression, valve clearances, spark quality/timing, clean/oiled filters, all have to be good before tuning the carbs. After all this stuff has been checked, then you can test and re-jet. Don't cut any corners or the jetting is more difficult.

I have to tear the top end apart?!? Valve clearances? Man. If that is true forget it. I don't have gaskets for all that or the time for that matter.

Compression test. I have seen this posted before. How do I measure it? Is there a special tool?

I think you said the DJ carbs were cleaned and rebuilt? Did you do the work? I just want to say that I've heard that line many times and actually nothing was done. I've also heard "the filters are cleaned and oiled", but they were really oiled with motor oil. That right there will cause bad gas mileage. As for a good spark, in a darker garage, the spark will be blue and fat. If it's yellow or orange, you have a weak spark. If the above mentioned checks are good, then there are reasons the carbs are wasting gas. One of them is they're probably not clean enough. Another can be the float levels. Another the jetting/synch. The carbs need to be cleaned/inspected.
Do you have a good manual or do you need specific info?
Are you going to do the work yourself?
Have you ever vacuum synched these carbs?
Do you have the tool?
Do you know how to chop test plugs?
As for a plug read, I do recommend a carb synch to get more accurate/uniform reads. If all the other checks are good, to get a solid read for the needle, mark your throttle housing and grip for 1/3 throttle. Make sure the bike's warmed up well, and go a couple of miles at that throttle setting and do a chop test. Avoid hard accelerating at this time. That can glaze the plugs. Just open her up to 1/3 and hold it. This is high speed, but you say that's not a problem for you. :twisted:
Any questions? Get back with the reads and we'll go from there.

I have never done any motorcycle carb work other than when I tore the Kaw carbs apart and cleaned them then put them all back together. I got lucky.

[first timer]

ok homie take a deep breath count to 10 relax, lets do one thing at a time. you go teh carbs off that good, i would start by just going thru the carbs and cleaning them, basiclly take one carb apart at a time and and anything that does look like dirt either romeve or soak till it comes off. this will requre a little bit of memory cause the vms are kinda like a puzzel and you have to remove a bunch of stuf just to get them apart, have some one with a good memory watch you.

don't get stressed out about this that only makes it harder. so for now work on cleaning a set of carbs it will do you good nad get you in a good mind set to start working on other things.

after you have you carbs apart and reassembled then work on replaceing the o ring gaskets whilke the carbs are off. if you look at he whole pictue you will blow your mind so do only one thing at a time, you can do this it's not that hard. you just have to be backed up in a corner and desprate to have a running bike in order to be motivate to to the work. i was there now i look at fixing a bike like i think about breathing.

-ryan

[Hoomgar]

Thx dood I know I can do it too. I got you guys

I have them open and yes the two center ones look like they were cleaned out with a knife. Scraped clean. They need cleaning.

I will do just that. I have two complete sets here so here goes.

No turning back now!

[first timer]

you will need some berryman carb dip and about 3 bottels of carb spray, don't forget to get some orings for the carbs from robert barr these are all musts, before you dip make sure to remove all rubber peices also let each carb soak for at least a hour or more.

some tricks i learned, use a impact screw driver bit to remove the screws keeps them from stripping. also when removeing the float bowl gasket use a flat razor and lots of carb spray to soak the gasket and slowly see if you can pry off the gasket so you can reuse it. i also found that useing a old tooth brush and warm water and some dish soap to do a intial cleaning helpful before dipping. so to remove the big stuff.

don;t forrget to blast every passage you find with the carb spray red staw stuck in the hole, every hole you find should have another end so when you spray it will squirt out it, other wise you have a clog.

-ryan

[Anonymous]

Too much to read so if this has been covered I am sorry. Could your odometer be out to lunch? They can be off by a huge amount on these bikes which results in a really bad mileage calculation.

Steve

[KEITH KRAUSE]

OK Mark. Hope I have this straight. You want to keep the carbs on the "new" bike the way they are for now, so you have a bike that runs. That means we can service the carbs that came with the other bike and already have a DJ kit. Sound good? I think there's no pressure or rush this way.
We can set up the carbs and just hope that the other stuff I mentioned is good or will be later on, such as the timing, etc. I was just trying to do things in order, but we can work with what we have if you like. I just didn't want to see you spend time and money on the bike and find out you have major problems that would make you want to forget the whole thing.
By valve clearances, I meant to check the tappet clearances. A search here will give you detailed info on a quick compression check.
As for the carbs, the leaking you just discovered will probably be the main reason for the bad gas mileage. A simple cleaning/ inspection and maybe some replacement parts will fix this.
Let me give you an option. I can try to walk you through the carb work if you like. I realize I'm not the only help you have but I will be busy this weekend and I'm not sure how much I can help. So if you're relying on me, I apologize. The option is, I can do this carb work for you and not charge you an arm and a leg. I can do better work than any shop around.
Let me know in a PM if you would rather have me do the carb work. If you want to try, that's great. As usual, gotta run off to work. :roll: Keith.

[Hoomgar]

Thx guys. Steve, you could be right as I already suspect the speedo is off and they are joined at the hip but it isn't off that much. Not in a 100 mile or less calculation. Even if it is off it is still bad.

Ryan, I am looking into carb dip now. Maybe parts cleaner?

Keith, read the first two posts on this second page. The game plan has changed, I am working on the carbs for the bike now as they are screwed!

I need to get these squared so I can get the bike running.

[first timer]

nope you need "carb dip" berrymans should be available at most retail auto part stores if not go to napa tell that you want a gallon tub of berryman and if they don't have it can they order it or order somthing very close. it's a pretty common thing.

-ryan

[Hoomgar]

Well I am at that point so out I go. The entire rack is completely disassembled. I mean completely. There isn't a thing left that could be taken apart or unscrewed.

I threw everything together into a big tub of WD40 to soak.

NOT! J/K

I have every carbs parts each in their own cup. The bodies are stripped, carb cleaner cleaned until all orifices are open and ready to dip.

Oh, the carb boot o-rings are all very good looking. They are soft and pliable, not swollen and quit frankly, look new? Maybe just put in.

Side note. You saw the pic of plug number three? Everything about cylinder 3 is funky on this bike. The spark plug socket is cross threaded about 1/3 of the way in. Carb 3 was gummy while the rest were not. The carb boots all came right off the same except the boot on number 3, it's screws were corroded in places and took some finesse to get out. The float needle in number 3 was particularly gummy.

I am going to clean out my tank, check the petcock screen and get a proper motorcycle fuel filter for it while I am at it.

I'm on this. Thanks for all the help. I have never been more committed to a cycle repair than this before.

What do I need to get in order to sync the carbs? A Manometer? <--spelling

Can I make one?

BBL

[Hoomgar]

Who can point me in the right direction for a carb balancing tool?

[first timer]

any bike shop can order one, i have heard good things about the carbtune sync meter, basiclly i think you can get a pretty good one from jc whitney, make sure you get the kind that uses mercury they are more acurate.

congrats on getting everything apart you are half way there, was so hard was it.

-ryan

[Hoomgar]

No it really wasn't man. I got some carb dip. It's Gunk brand and is environmentally safe? Guess that means it wont work

No actually it worked nice. They all look nice and shinny new now. All passages open and clean. Every single o-ring in these carbs was tar when I opened them. They simple crumbled out. All of them! Only the boot o-rings were good but upon closer inspection I can see that even they could use replacing. Where is the best place to get all the o-rings I need for these carbs and quick? Bike Bandit only stocks about 2 of them :?

I bought a 4 carb rebuild kit off eBay today for these carbs. Hope I didn't get snookered? Was this a good buy? http://cgi.ebay.com/ebaymotors/ws/eB...tem=4543738108

I hope so. I also got another set of bowl gaskets. Time to stock up.

Oh, I also got a compression gauge and got those cylinder pressure reads.
I had to take them cold of course as the bike isn't running but here was the results read after one minute wait on each cylinder. There was virtually no fade at all on all four of them. I think they are good right?

Cylinder:

1 = 110
2 = 106
3 = 112
4 = 118

I just need o-rings and gaskets now in order to reassemble.

I am looking for a carb tune up tool. The Morgan Carbtune II is going to be it if nothing else comes along.

One more, I know I have a lot of questions here but your answers are greatly appreciated guys. How can I tell what size and make these mains are? There is no markings whatsoever on them. But the hole in them just looks really big to me for a jet in a stock 997 engine running 26mm carbs? Here are some pics of them:

I could drink through that hole!!!
[img]http://groups.msn.com/_Secure/0SwAAAM8VDC0B7pt!Rfu!4T8NONh7MDp5ct399PY7ahbSZqA9p Hi99CZ2bwIKoeE0Arm4EVNBy609MLJ0XtjZZdhHWTC!WVSIOjK x9t2*vPRm*P6XMrCztQ/DCP_7215.jpg[/img]

What make is this? How can you tell?
[img]http://groups.msn.com/_Secure/0SwAAAM4VyiwB7pt!Rfu!4T*tqMSoX!Nk9gi90znFvuSDPJHBJ cZDwSH8uvdDxIuUQesiEPTXjs2yxDyA1RHgtBQ0o74JxfhMYoV 4HmepBwfhJVeQxUeljA/DCP_7214.jpg[/img]

[KEITH KRAUSE]

Hi Mark. Glad you decided to tackle the carbs.
The rebuild kits you bought look OK from what I can see. Some parts were necessary, some not. If you want to do a complete job on these carbs, I would order the o-rings from Robert Barr, a member here. I think he wants about $16 for all the o-rings. There's at least 5 in each carb to replace.
I use a Motion Pro mercury vacuum tool. It's simple, but works as good as the person using it. Morgan Carbtune costs about twice as much ($80) but uses metal rods instead of mercury. Mercury works well, but if you take a longer time to synch and you turn it off because of the motor getting hot, condensation can get trapped in the mercury columns and make the levels harder to read.
Since you're not going to put the DJ carbs on the project bike, I think you should take out the DJ parts and use them in these carbs. I doubt you can re-jet with the stock jet needle. I can then give you the jet settings I hope will get it right the first time, which is difficult to guess though. Sound like we're on the same page?
Do you have a manual, or hopefully a factory manual? If not, I'll try to peak in during the day to see if you have questions.
After the carbs are cleaned up and blown out with high pressure and any o-rings replaced, you need to get some verniers and measure the float levels. First make sure the floats are not tweaked. Measure both sides of each float and gently bend so they're the same. Then set them to the exact middle of their factory range, which will be .94". Measure from the base of the carb body, without the bowl gasket, (don't place your measuring tool on the small gasket ridge) to the top of the float. Hold the tool straight and slide it across the top of the float so it BARELY touches. Carefully bend the tab that contacts the float valve tip, to get the level you want. Double check your work.
At this point you'll still have to swap out the needle assemblies, check/adjust the needles before installing, install the DJ mains, bench synch the slides for the fully closed and fully open positions, and set your side air screws and pilot fuel screws. Followed of course, by the vacuum synch. Did you keep a record of how far out each pilot fuel screw (underneath) was? If not, set them at 1 1/2 turns out to start. Remember to only seat them LIGHTLY to avoid damaging the sharp tip. The side air screws can also be set at 1 1/2 turns out to start.
Regarding the needle assemblies, use a good fitting tool to remove the two Phillips screws down in the slide. They must be removed to swap the needle and make adjustments. This assembly takes some finger dexterity to re-assemble. Make sure the two plastic spacers, a thick one and a thinner one, go back on the DJ needle in the same order. The thick one goes above the needle e-clip, the thinner one goes below the clip. Any jetting spacer you may still have, (if we used it) would go on top the e clip. I think in your case, we won't use a jetting spacer if you have it. So install the e-clip in position #4 (from the top) of the DJ needle. Be sure the thin brass plate that goes under the throttle valve arm goes back the same way it came out, don't flip it upside down. It has a small tit on it and it fits into the arm. You'll see, just be aware. Don't over tighten the screws, the heads strip if over tightened.
Install the 138 DJ mains, if that's what the carbs have. The DJ mains will have the # stamped right on top. Yours may say 142?? If no #, I don't know what's going on. Mikuni's also stamp the # in the same place and have a little symbol, like a small square inside a larger square. I would re-use the stock Mikuni pilot jets, don't use the pilot jets that came in the rebuild kits.
That just leaves the bench synch for the fully open and closed positions.
As usual it takes me longer than I want to admit to post this. I don't want to take too long because the posts are "timed" or something, and I click submit, and I get an invalid message and lose everything. I'll post the bench synch info, I hope in time for you, tomorrow AM. The synch is very important, you want to get it right to make the vacuum synch easier. Also, the fully open position is important. Later.

[Hoomgar]

Thx for all the info Keith. I am moving on and need a few easy questions answered by anyone who knows?

1. Must I/should I clean the floats as well? They have that rusty looking fuel stain on them. If so, how and with what? I didn't want to dip them as that seemed unsafe?

2. All the needles were set at the 4th position down from the top except the one in carb #2, it was set in the middle or the 3rd one down. Does this seem right? Wouldn't they all be in the same position?

3. What is this stuff I removed from my oil plug and the bottom of the pan when I changed the oil today? It is soft and rubbery and is orange/red in color? There was a bunch of it, pictured is just some that I picked out and wiped off for the photo.
[img]http://groups.msn.com/_Secure/0TwAIA40Y!fVGOsYCyYkYaEglCfCCII3GFG75GoLp*t!ES6yMO JWet6WVZ84tHO3Q4FLbI16DXuAop1bB6d60*jmd2vDZXN1gyau XQpSB5M8dQdMc5G566g/ForeignMater.jpg[/img]


Now onto business. Amos (having younger and better eyes) was able to read marking on the mains that I could not see. The mains in my carbs said R and two little squares and the jet size was 132.5

The mains in my other old set of carbs just say 118. I am running the old carbs as is right now just to see what they do. It runs fairly smooth out to red-line with no perceivable flat spots but lacks power. I took a plug read and it is decidedly lean on all four cylinders. Some worse than others and #4 being the best. I noticed that the screw on the bottom of carb number 4 was sitting out considerably further than the other ones. So unless there is a lot of room for adjustment I would say these 118 mains that I though were DJ and am not sure what they are now may not be big enough. Here is a pic of the plug read taken hot after 3+ miles at 1/3 throttle:
[img]http://groups.msn.com/_Secure/0SwD4AssVBSwB7pt!Rfu!4a6FAqWRHdXzIzbLb8X6BIzuVEyB* nc5lhPDJ9XXPB3VtPmcuF9FECNR!TOKk6h9qT9EjV8cX2DTHnc aw5VesBmtOKjA77s!og/DCP_7220.jpg[/img]

Remember, these are vm26ss carbs and are small. But what do I know? It just seems to me that the 132.5's in the original carbs would be big but maybe I am wrong. I am only playing with these old carbs on the bike to see what they did. I feel certain these jets will be too small. Maybe we stick with what is in the bike already?

I will order those 0-rings now.