Won't start easy, idles bad, and 1&2 not firing well.

[zanza14x]

Hello everyone,

I would just like to mention that after only a couple days of knowing about this site, I have learned quite a bit, even as a relative motorcycle novice. Keep up the great work!
OK, now I know that these questions have been asked more or less in different forms, but I can not really make heads or tales about my specific situation with all of the different suggestions. So, here it goes.
First of all, I am now a proud owner of a 1978 GS550(E). The bike, when I first got it, started relatively right away on choke, without starter fluid or prime etc. At that point, all of the fluids were new, the plugs were all new and the right type, and the carbs had been cleaned with seafoam run through them. The first problem is that the 1&2 cylinders have never really warmed up until the bike has been run for a while. At first, it took 30+ mins to get them even warm (the other 2 warmed right away), but after running the bike a few times with good high octane gas and seafoam, they now start to get warm after about 5-10 mins. Now I beleive that both of the pulgs have spark, etc., and that the passages are pretty much clear, but I did notice some "bluing" on both of the cylinders, which may indicate too lean of mixture? Also, after syncing the carbs, the bike has had a pretty hard time starting and especially idling. It just kind of baffles me that it has become progressivly worse. Now the guy that I worked with to sync them did mention that the compression seemed a bit low, which could indicate a vacuum leak, which I still need to look into. Not sure if this could be the main issue. Basically, if the bike has been sitting, always in a garage or under a cover, a day or two, it takes about 5-10 mins to get it started. It will start right away, with starter fluid and on prime and choke, and it will rev up for a couple of seconds to about 4K RPMs, but then it goes down to about 1K, (about where I had it set), and then just dies. It then becomes an absolute pain to start after this. I really hope this won't fry the starter or the points. When it finally starts, it barely will idle on 1K, but if I even touch the throttle for 10+ mins, it just dies, totally unresponsive to any gas. Then when I can finally coax it to take some gas, I have to quickly shut the choke to 1/2 or OFF and then crank the RPMs up to around 4-5K and only then will it BARELY take off. Even after this, it will only idle (around 2K) after driving it a few blocks. Although, once the beast is warm, it flies. Basically, I just want it to start as quickly and easily as could be expected without having to restart it over and over and not having to wait 15 mins for it to even be "workable", if at all possible. I am kind of thinking that the cylinders and the start/idle problems could be connected...
Sorry this is a long inquiry, but any helpful advice would be greatly appreciated. Thanks.

[Octain]

Before ya grab another tool spend a few days here.

http://members.dslextreme.com/users/bikecliff/

[earlfor]

Since the problem is with cylinders 1 and 2, I do not think it is an ignition or coil problem because 1,4 is one ignition pair and 2,3 is the other.
Sea Foam will not "overhaul" a carburetor. It will remove minor glazing, but thats about it. Since as you say, its the 1,2 carb, I will guess that the bike sat on the sidestand for a lot of time unused and being leaned that way, the 1,2 carbs would be most prone to sludge and varnish build up.
I believe the solution is to remove the carbs, disassemble them (at least the 1 and 2 carb), soak them in berrymans and install new "O" rings. Gummed up carbs is the likely culprit.

You might want to do a compression test first. If the valves are not closing correctly, you would have low to no compression and consequently no vacuum either. No compression/vacuum, no fuel flow.

Earl

[Steve]

I see a lot of issues here, so I am just going to paste what you wrote and insert my comments.

Hello everyone,

I would just like to mention that after only a couple days of knowing about this site, I have learned quite a bit, even as a relative motorcycle novice. Keep up the great work!
OK, now I know that these questions have been asked more or less in different forms, but I can not really make heads or tales about my specific situation with all of the different suggestions. So, here it goes.
First of all, I am now a proud owner of a 1978 GS550(E). The bike, when I first got it, started relatively right away on choke, without starter fluid or prime etc.
'Choke' is good, PRIme is only necessary if you have not ridden the bike for about a month, and the BEST place for starting fluid is on the store shelf. YOU DON'T NEED IT.
At that point, all of the fluids were new, the plugs were all new and the right type, and the carbs had been cleaned with seafoam run through them.
It's OK to run Seafoam through carbs that have been cleaned, but simply running Seafoam will NOT clean carbs that have been sitting for a while and need a rebuild.
The first problem is that the 1&2 cylinders have never really warmed up until the bike has been run for a while.
Are you riding the bike during that 30 minutes or simply idling in the driveway?
At first, it took 30+ mins to get them even warm (the other 2 warmed right away), but after running the bike a few times with good high octane gas and seafoam, they now start to get warm after about 5-10 mins.
With a stock engine, there is no 'need' to run high octane gas. In fact, it will hurt your overall performance.
Your pipes should be too hot to touch after about 10 seconds of running.
Now I beleive that both of the pulgs have spark, etc.,
Belief is nice, but have you actually checked for spark? Pull a plug and actually observe it sparking.
and that the passages are pretty much clear, but I did notice some "bluing" on both of the cylinders, which may indicate too lean of mixture? Also, after syncing the carbs, the bike has had a pretty hard time starting and especially idling.
Have you adjusted the valves? Mis-adjusted valves make it hard to start a cold engine.
It just kind of baffles me that it has become progressivly worse. Now the guy that I worked with to sync them did mention that the compression seemed a bit low, which could indicate a vacuum leak, or mis-adjusted valves which I still need to look into. Not sure if this could be the main issue. Basically, if the bike has been sitting, always in a garage or under a cover, a day or two, it takes about 5-10 mins to get it started. You must have a battery that is VERY good if it lasts that long. It will start right away, with starter fluid and on prime and choke, and it will rev up for a couple of seconds to about 4K RPMs, but then it goes down to about 1K, (about where I had it set), and then just dies.
As mentioned, get rid of the starting fluid. Instantly revving to 4000 rpm does not give it time to build oil flow.It then becomes an absolute pain to start after this. I really hope this won't fry the starter or the points. When it finally starts, it barely will idle on 1K, but if I even touch the throttle for 10+ mins, it just dies, totally unresponsive to any gas. Then when I can finally coax it to take some gas, I have to quickly shut the choke to 1/2 or OFF and then crank the RPMs up to around 4-5K and only then will it BARELY take off. Even after this, it will only idle (around 2K) after driving it a few blocks. Although, once the beast is warm, it flies.
All of these descriptions are telling me that it is a valve adjustment problem. Basically, I just want it to start as quickly and easily as could be expected without having to restart it over and over and not having to wait 15 mins for it to even be "workable", if at all possible. I am kind of thinking that the cylinders and the start/idle problems could be connected...
Sorry this is a long inquiry, but any helpful advice would be greatly appreciated. Thanks.

Two things that will help you retain what little sanity you might still have:
1) TOTALLY clean the carbs. Take them completely apart, dip them in Berryman's carb cleaner dip, re-assemble with a new set of o-rings from cycleorings.com
2) Adjust the valves.
After your valve adjustment and carb cleaning, re-sync the carbs.

When everything is properly done, you will use about 1/2 'choke', leave the petcock on ON, throw the starting fluid in the trash. Using 1/2 'choke' will have it running about 2000 rpm, put your helmet on, get on and ride. By the time you get into second gear, you can turn the 'choke' OFF.

Yes, it's really that simple.

.

[Nessism]

Yup, do a complete carb rebuild. You have VM carbs so find the appropriate tutorial on how to rebuild them. You will need an O-ring kit from cycleorings and new O-rings for the intake pipe boots. Cycleorings.com does not sell the size you need for your bike so either order some new ones from a dealership or I have some spares I can send if need be (PM me if you want to discuss).

Oh, and adjust the valves while the carbs are off as the others have said. There are no short cuts to a properly running bike. Neglecting the valves is BAD and will cause engine damage. Many many GS bikes die a horrible death due to neglected valves.

Good luck and welcome.

[spyug]

As our leading experts have told you, there is no quick and easy fix to this situation and half assing it will only get you more frustrated. Pull, clean and rebuild carbs, set valves, synch carbs...that is the sequence.

Now once you have done that and the bike is running right you are going to want to look at the charging system. Dollars to donuts, you are going to have issues there too. Nothing worse than a good running bike that might leave you stranded.

It seems like a big task and a lot of work but trust us it needs doing if you want a reliable easy starting ride. Do it right once and you'll be good for many fun filled miles. We've all been there once or twice.

Good luck with it and keep us posted. Oh and lots of pics are mandatory herabouts.

Cheers,
Spyug

[BassCliff]

Greetings and Salutations!!

Hi Mr. zanza14x,

You've got a good bike but it's old with an unknown history so, yes, it pays to do all the basic maintenance/repairs right up front so that you have a known quantum of mechanical being. The following should help get you started in the right direction. It's just how I say "HOooooowwDY!"

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[zanza14x]

Hi everyone again,

Honestly, I am overwhelmed with the amount of info provided, (which is a good thing). Thank you all very much for the info. Just to get a couple of things clarified. I did get the carbs cleaned, the jets, (according to the guy who cleaned them), were cleared out and everything got cleaned as well as could be expected. I just ran seafoam through them for a tank or so mainly to get anything out that it could, as well as, yes I admit it, I love me some seafoam. Although, earlfor, I beleive you are correct about the bike on the side stand, b/c I remember being told that the 1&2 side carbs were much nastier than the other two. Now, when someone says to "rebuild the carbs", does that automatically mean putting in a whole new carb kit(s), or just cleaning them up well and putting in new O-rings? Also, would these specific O-rings, due to the fact that the mentioned website does not have them, would a hardware store have such a thing, or is that just an ignorant dream? Steve, when you ask about the bike running to get the pipes heated up, it takes them about 10 mins as i mentioned, but that is idling in a driveway. This is simply because it will not be driveable at this point unless it is allowed to "warm up" for 10-15 mins, which I know on a aircooled machine is not good. As far as valves, and please forgive my ignorance, these valves that are mentioned are valves that control the richness, or...? And where might these be located? Lastly, thank you so much for the warm welcome, and for the FREE manuel. It will indeed keep me busy reading for many cold nights to come.

[Steve]

OK, Q&A, part 2

Hi everyone again,

Honestly, I am overwhelmed with the amount of info provided, (which is a good thing). Thank you all very much for the info. Just to get a couple of things clarified. I did get the carbs cleaned, the jets, (according to the guy who cleaned them), were cleared out and everything got cleaned as well as could be expected. "As well as could be expected" really does not say that they were CLEANED. A proper cleaning involves taking the rack of carbs apart, completely disassembling each carb, dipping all the non-rubber parts in carb dip, then re-assembling with new o-rings. Just opening up the carbs and spritzing some carb cleaner spray just will not do it. Your lack of heat on two cylinders is evidence that gas is not flowing through the pilot circuits for one reason or another. Dirty passages in the carb bodies is one possibility. Until you change that possibility into a certainty, you just don't know. I just ran seafoam through them for a tank or so mainly to get anything out that it could, as well as, yes I admit it, I love me some seafoam. Seafoam is OK for keeping them clean, but it just won't unclog the passages that might be blocked. Although, earlfor, I beleive you are correct about the bike on the side stand, b/c I remember being told that the 1&2 side carbs were much nastier than the other two. Now, when someone says to "rebuild the carbs", does that automatically mean putting in a whole new carb kit(s), or just cleaning them up well and putting in new O-rings? Do not waste your money on "carb kits". For the price of just one kit (and you will need four of them), you can get a complete set of o-rings from cycleorings.com. If you get the kits, you will get some brass pieces of questionable quality, a bowl gasket and a couple of o-rings. You need more o-rings to finish the job, so just get the proper kit to start with. Also, would these specific O-rings, due to the fact that the mentioned website does not have them, would a hardware store have such a thing, or is that just an ignorant dream? Not an ignorant dream, but hardware store o-rings are not the right compound of rubber for this application. Steve, when you ask about the bike running to get the pipes heated up, it takes them about 10 mins as i mentioned, but that is idling in a driveway. This is simply because it will not be driveable at this point unless it is allowed to "warm up" for 10-15 mins, which I know on a aircooled machine is not good. Evidently the pilot circuits are not flowing fuel. Could be blocked passages in the bodies, could be as simple as a mis-adjusted pilot fuel screw. No way to tell at this point, but you will be very happy with the results if you clean the carbs. This will likely be a once-in-a-lifetime deal, unless you ignore and neglect the bike long enough for the carbs to gum up again. Since you like Seafoam, did you know that it works well as a winterizing agent? As far as valves, and please forgive my ignorance, these valves that are mentioned are valves that control the richness, or...? And where might these be located? These valves are the ones that allow the fuel/air mixture into the cylinders, then allow the burnt mixture into the exhaust pipes. They are on top of the engine, under that large, H-shaped cover. Lastly, thank you so much for the warm welcome, and for the FREE manuel. It will indeed keep me busy reading for many cold nights to come.

.