WOOT! It RUNS! (Sort of...)

[Taliesin]

So, after a full carb clean, valve clearance check, oil change, intake o-ring change out, air filter cleaning, carb o-ring replacement, and throttle-clutch-choke cable lube, my bike runs. For a little bit...

What happens, is we adjust the master idle screw to about 1750 rpms in preparation for syncing the carbs. The idle seems ok for a little while: 30 seconds or so. Then it starts to die off....and then it dies. Adjusting the master idle screw brings it back to 1750 for a little while....before repeating the dying procedure.

Mixture screws on the carbs are set 2 turns out from lightly seated.

Thoughts? We were thinking we might need to tweak the mixture screws, but we don't have a Colortune. (And can't afford one right now, frankly.) We have a Carbtune waiting in the wings, if we can get things to be a little more consistent.

Also, the throttle seems a little sluggish after the dip. I tried to use some silicone to loosen it up back to being snappier, but it does seem a tad sticky. How can I lube up those butterflies....preferably without having to remove those *&#^$ carbs.

One final question: What do people do with that vacuum hose that normally goes to the petcock? I've got an aux tank hooked up to the carbs right now so I can have access without the normal fuel tank getting in the way. Should I have plugged up that vacuum hose or something?

 

[Steve]

So, after a full carb clean, valve clearance check, oil change, intake o-ring change out, air filter cleaning, carb o-ring replacement, and throttle-clutch-choke cable lube, my bike runs. For a little bit...

What happens, is we adjust the master idle screw to about 1750 rpms in preparation for syncing the carbs. The idle seems ok for a little while: 30 seconds or so. Then it starts to die off....and then it dies. Adjusting the master idle screw brings it back to 1750 for a little while....before repeating the dying procedure.

Mixture screws on the carbs are set 2 turns out from lightly seated.
Try 3 turns.
Thoughts? We were thinking we might need to tweak the mixture screws, but we don't have a Colortune. (And can't afford one right now, frankly.) We have a Carbtune waiting in the wings, if we can get things to be a little more consistent.
Colortune is nice, but not necessary. You can tune for smoothest/highest rpm when the carbs are synched.
Also, the throttle seems a little sluggish after the dip. I tried to use some silicone to loosen it up back to being snappier, but it does seem a tad sticky. How can I lube up those butterflies....preferably without having to remove those *&#^$ carbs.
Butterflies? They only pivot on a shaft. You mean the slides? No need to do anything to lube them.
Most lubes (with silicone a possible exception) will only attract dirt, making the situation worse.

One final question: What do people do with that vacuum hose that normally goes to the petcock? I've got an aux tank hooked up to the carbs right now so I can have access without the normal fuel tank getting in the way. Should I have plugged up that vacuum hose or something?
YES, that should definitely be plugged. Otherwise, you have a very SERIOUS "leak" in #2's system.

and ten more characters

 

[81gs1100]

Do you have the air box connected? Without the airbox the bike wil run really lean and wll act in a similar way.

And yes, plug the outlet that would be the petcock hook up.

Also I you said that the idle is good and then drops off, does it ever race up after any throttle movment? Does your aux. tank have a vent? Are the carbs vented?

 

[Taliesin]

You guys are awesome.

Vacuum tube was not plugged. It will be.

Aux tank is not vented. It will be.

Thank you. I'll keep you posted.

 

[Steve]

Does your aux. tank have a vent?

Aux tank is not vented. It will be.

Depending on what you use for an aux. tank, it might not need to be vented.
I use a gallon oil jug with a hole in the lid through which I put a piece of tubing.
The sides of the jug are flexible enough to not inhibit fuel flow due to lack of venting, at least for as long as it takes to adjust the carbs.

I also have the advantage of a fuel valve, of sorts.

Fuel ON:

Fuel OFF:

Yeah, I know it's not normal to have the REAL gas tank on while doing this, I just staged these shots to show the AUX. tank.

.

 

[Taliesin]

I dig the oil jug.

I have the MotionPro aux tank, which has more rigid sides than the gallon oil jug. Tonight, I was planning on just leaving the screw cap off the tank, to see if it made a difference.

I have no idea how long it's going to take to use the Morgan Carbtune once I get my idle stabilized as described below.

You had mentioned that I wouldn't need to worry about lubing the throttle slides. I'm probably confused as to what the slides are. Also, if the throttle isn't as "snappy" as it could be, how would I solve that, considering that I did lube the cables really well?

Thank you guys again for all the help. Seriously. Couldn't have done all this without these forums. I am a mechanic NOOB in every sense of the word. Never even changed my own oil, and never IMAGINED I'd do anything as complex as a carb clean. People who know me think I am insane for doing all of this.

 

[tkent02]

You had mentioned that I wouldn't need to worry about lubing the throttle slides. I'm probably confused as to what the slides are. Also, if the throttle isn't as "snappy" as it could be, how would I solve that, considering that I did lube the cables really well?

You should have CV carbs, yes?
The slides go up and down with vacuum, controlled by the throttles which are butterfly valves like a car throttle.
The throttle cables could be routed wrong, kinked, worn internally, adjusted too tight.
All of these will make it harder to twist the throttle open, and keep it from snapping shut when released. Might be a few other causes too.

 

[Taliesin]

Ok, the slides seemed to move fine when I put them in, etc.

It was the butterflies that seemed really sluggish after I'd gotten everything dipped, etc. When I turned the throttle the butterflies seemed really stiff, and didn't snap closed. I tried to spray some silicone on the rail on which they turned, which helped some, but it's still less snappy than I'd like. Of course, that may get better with use.

 

[Steve]

Was the throttle cable attached when you checked the butterflies? If so, it could be your problem.

If not, you might try spraying some carb cleaner into the pivot areas on each carb.

.

 

[Taliesin]

The throttle cable was not attached. This was immediately after the dip, and even before I had reassembled the carbs.

If, after a bit of operation around the neighborhood this doesn't solve itself under use, I guess I'll have to pull out the carbs again and spray that pivot area.

Thank you for the pointer. I'm getting excited to ride again. This bike has been down for over a month, and it's been really getting me down. Glad that all the work is finally paying off.

 

[Taliesin]

Things appear to be shaping up nicely. Plugging that vacuum hose and removing the screw top of the aux tank caused it to run consistently without dying. YAY!

One final question...for now.

Does everyone else use that nifty tool from Morgan for adjusting the vacuum? I can probably get at the #1 and #4 screws and locknuts, but that #2 is going to be a pain. $19 doesn't seem too much when I see what some people pay for angle drivers, etc.

 

[Matchless]

T

Does everyone else use that nifty tool from Morgan for adjusting the vacuum? I can probably get at the #1 and #4 screws and locknuts, but that #2 is going to be a pain. $19 doesn't seem too much when I see what some people pay for angle drivers, etc.

Yes it helps a lot. I made my own, long screwdriver, welded a socket to the end of a piece of tube and have used it on a couple of bikes already. The tube needs a handle to stop it turning slightly when you tighten the locknut.
Good to have, although you may not use it much.

 

[Steve]

I thought about getting one of those tools, until I had the pleasure of actually using one. A couple of them, actually, on different bikes.

I have not seen a bike yet that makes it easy to get to the adjustment between carbs 2&3. Even 'the tool' can't do it because you can't get a straight shot, due to the throttle cable bracket or the clutch cable bracket. I was going to have to fight that center adjustment anyway, so I just refined my method.

What I have found to work best happens to work best if you start with the carbs off the bike. Loosen all three locknuts (they are usually jammed quite tightly), then put the carbs on the bike. Warm the bike up, do your vacuum sync, which is easy, because the adjusters will turn easily. Now you only have to snug down the locknuts. That is not nearly as hard as trying to break them loose. Look at your gauges, make sure nothing changed, shut it down, put stuff away, go for a victory ride.

.

 

[Taliesin]

MAN.... lol. I'm gonna have to take these darn carbs off again.

Thanx for the tips, guys. I really do appreciate it.

 

[Taliesin]

Thanks to everyone who has helped me, my bike is now up and running again.

I had a high idle problem, which is now fixed. Had some flat o-rings as well as a stripped cylinder head bolt which I helicoiled.

I also had an issue where I'd lose power if I went above 5K RPM's. Engine would just sort of die down even though I had the throttle pegged. I read a lot on these forums indicating that my main jets could be clogged, or I could have some sort of fuel starvation issue. I decided to see how things behaved after the clean and dip, and my power loss issue seems to be very much resolved.

I did a carb disassembly, clean, and dip. Checked valve clearances (1 was out of spec, so I replaced the shim.) Changed the oil. Lubed all the cables.

Now, everything seems to be running quite awesome, except one thing..... lol

Now that my bike is running better than it did, when I roll on the throttle to get it up to speed, it's almost like the clutch disengages itself. The engine winds, but I don't get any power to the wheel when it happens. I could achieve the same effect by actually squeezing the clutch lever.

I can get her up to speed if I accelerate slower, being careful to not exceed a certain threshold, after which the clutch just sort of disengages. It's almost like the clutch isn't fully disengaged when the lever is released. The friction zone is right at the very beginning of the lever pull, which is what leads me to say that.

I'm kind of assuming this is a cable adjustment of some kind, but for some reason, I'm having a hard time grasping which way to adjust to achieve what. I'm going to do some searches this morning when I get a chance, but thought I would post it here, since I wanted to let you all know she is running really well!!!

 

[fenderfreek]

Do you have any free play in the clutch? It should be all but completely slack for the first 1/4" - 1/8" of travel before it actually engages. Only the resistance of the return spring.

Second possibility is that it's just plain worn out. A likely cause of clutch failure if it's high mileage or hasn't been maintained.

Third possibility is that the springs are worn - you might need to replace half of them with some extra power clutch springs if the other two things I mentioned are okay, though a 550 would be a lot less prone to this one.

 

[Taliesin]

There is no free play in the clutch at all. The clutch doesn't disengage until I've completely let out the handle, which leads me to wonder if it's fully disengaged at all.

I'm trying to remember the mileage, but I want to say it's around 65K miles. Was pretty well maintained, though it sat for awhile before I got it. When you say worn out, are you talking about the clutch plates, the cable, or the whole shebang?

The springs are the easiest thing to replace, right? Seems to me I might want to start there and see where it gets me?

 

[rudy]

Start with a cable adjustment. It's free. There will be an adjuster at both ends of the cable. Thread either one in more to give yourself more freeplay. If the one at the handlebar is already all the way in, take a look at the other end at the engine. Some GS cables have an adjuster in the middle of the cable as well. Your clutch lever should be slightly loose when you're done.

If that doesn't change anything, then start with changing out clutch springs. It's easy to do. When you get the new springs, get a clutch cover gasket as well. You'll likely destroy the old one.

 

[Taliesin]

Thanx, I'll try that and see where I stand. Easy and free is the best first solution.

And thanx for the gasket tip. I'll be surprised if I don't destroy more than the gasket, but hey, I managed to get the carbs back together ok!

So one question, even though the cable adjusters are pointing different ways, threading them in accomplishes the same thing? I know for a fact that the one on the handlebars is not all the way in, so I'll start there.

Thank you again!

 

[850 Combat]

Adjusting either end of the cable in a way that makes the effective length of the cable housing longer removes free play. Going in the other direction adds it. Go too far with the free play, and the clutch will not release all the way and will drag.

Letting the clutch slip will ruin it. When you detect slippage, back off the throttle and let the clutch hook up. Running too much oil can wet the plates too much and cause both slipping and dragging when cold.