1985 GS550EF a few questions

[satchmo]

Ok.

Here's the dealeo.

1985 GS550EF stock as far as I know, but missing the fairing-- sat all winter with old gas in it (I know I know, I was lazy). Fired her up in the spring with no noticeable problems. She's had about 5 or 6 tanks of gas through her with no problems.

Rode her around a bit, no noticeable problems. (mileage was low, but I figured that was because it needed a good sync.)

But now she temporarily has these fits of not liking me. She starts fine every time, no problem. First touch of the button.

But say maybe 10% of the time now, I'll ride for a while, no problems, and then she'll start acting weird. She'll die if I pull in the clutch and don't give her gas, she loses power when trying to accelerate, and if I put her in neutral at a light, she'll die if I don't keep the throttle on. When she does this I can smell gas, or at least my girlfriend can, I notice it sometimes, but not all the time.

Here are some other things I've noticed. She has creeping idle. Idles normally when cold, but once warmed up, she has considerable creep, and will gain 2000rpms or so at idle. Enough that if I let the clutch out without giving any throttle, she will start to pull away.

She also has a bit of an oil leak around the valve cover gasket. Not huge, and I know that needs to be replaced (I actually have a replacement around here somewhere).

So here are the questions.

1 --- from reading up it seems that leaky intake boots can cause the creeping idle --- is this correct?

2 --- I worked on my old carbs when I had the 77gs550, but this model only has 2 carb bodies -- what types of carbs are these? does anybody have a good link out there on how to clean them (the haynes manual I have which supposedly covers my year doesn't display this).

3 --- is there anything special to do to replace the valve cover gasket? The oil leak isn't terrible, but makes part of the engine look not so nice, and I'm trying to get everything to run right.

Thanking you in advance.

Satch

[KEITH KRAUSE]

Nothing special about replacing your valve cover gasket. You might want to try torquing the bolts first, just to see if they're a bit loose. Won't cost you to try. Correct torque should be about 8 ft/lb but look it up in your manual if it shows it.
Your carbs are CV's. Check out the CV carb clean up series here.
It sounds like an intake leak to me, but the symptoms contradict when you say the bike idles much higher when hot and also needs throttle to keep it idling at a stop. Little confusing to me.

[Nerobro]

Well crap. will you sell it to me? I want an EF.

Two things can cause the idle to creep. A weak battery, and leaky carb boots. The factory carb boot o-rings become really really crappy over time as they get baked to the head. Replace those o-rings With high temprature sillicone and you'll never have the problem again.

Treat your carbs exactly like any other CV carbs. They just are somewhat siamesed. :-) They'll make a lot of sence once you crack them open. Be sure to clean the choke jet!

[satchmo]

Nothing special about replacing your valve cover gasket. You might want to try torquing the bolts first, just to see if they're a bit loose. Won't cost you to try. Correct torque should be about 8 ft/lb but look it up in your manual if it shows it.
Your carbs are CV's. Check out the CV carb clean up series here.
It sounds like an intake leak to me, but the symptoms contradict when you say the bike idles much higher when hot and also needs throttle to keep it idling at a stop. Little confusing to me.

Oky doky.

I guess I should clarify. The idle creep doesn't occur when the bike is displaying the other symptoms (dying on idle, sluggish, etc.)

The idle creep only happens when the bike is running 'normally'.

I should add, that I've never, ever had a bike run normally, so I'm not really sure what that is.


Nerobro
You are more than welcome to the bike for $1200 CDN within the next day or two. :-)

Thanks for the tips guys and keep them coming.

[satchmo]

Follow up question

I've seen some others on here advocating running some type of fuel system cleaner in through the gas tank. Is this adviseable? I used to do this on my fuel injected car and it would work great, but I always thought that cleaner would wreck the o-rings in my carbs?

[KEITH KRAUSE]

I can't say if a DILUTED fuel cleaner will damage the o-rings, but I know typical cleaners at full strength will ruin them.
My opinion is if the bike is maintained the way it should be or repaired correctly when it has a problem/situation, such as a carb inspection/cleaning after the carbs have sat, then you'll never need these quick fix cures. Carbs can operate well for many years if the bike has fresh fuel and a clean fuel supply.

[KEITH KRAUSE]

As for your problem(s), you're still having two symptoms that usually don't happen concurrently. A high idle followed by low idle/stalling.
An intake leak, the most common reason for a high idle, generally doesn't go away. At the very beginning of a crack/leak in the intake system a leak can appear and disappear with temperature changes, making the rubber expand and contract. But very soon the crack/leak will expand and the leak will stay.
So it is possible you could have an intake leak AND a carburetion problem that causes the stalling at a stop. However, a poor idle can be valves out of adjustment or several other tuning issues, not just carburetion.
If you're sure there's no problem with the throttle cable hanging up, I'd focus on an intake leak because that should be the cause of the high idle problem. Fixing that may also fix the stalling problem.
If not, we'll cross that bridge when we get to it.

[satchmo]

Cool. Thanks for the info Keith.

I think my plan right now is to clean rebuild the carbs, replace the intake boots and o-rings, and sync the whole thing, as well as replace my valve cover gasket, and see how things go. That way I'll have dealt with a number of possibilities at least, and I don't think any harm can be done by doing these things. (although with me behind the wrench there are no guarantees )

I'll have to double check on the throttle cable hanging up though. I don't think it is -- what's the best way of checking?

[KEITH KRAUSE]

It's actually doubtful that your throttle cable is hanging up/not operating smoothly, based on your descriptions/symptoms. I just though I'd mention it.
Read your manual, but I believe your model requires zero throttle cable play.
Then it should be routed correctly, but a factory manual may be the only manual that shows factory cable routing.
If the cable is tight/catching and causing throttle return problems, you can usually expose this by starting the bike and then slowly turning the bars in both directions and testing the throttle return operation at a few points. The cable should never be allowed to effect the return action, even at full lock. If it does, then the cable routing or cable itself is wrong or ?