85 GS550L Carb Adjustment Question

[hikermikem]

Can someone instruct me as to the proper settings for the air mixture screws on an 85 GS550L ??

I've recently gotten this bike started after replacing the petcock. Apparently no gas was getting to the carbs.

I've also cleaned the carbs, replaced the air filter & plugs, and checked the plug wires. The issue is the bike now starts, but runs very poorly, with little power.

In addition, the idle creeps up very high (don't know how high - the tach is broken) as it warms up.

PS - I'm a newbie to this site & so far the info I've read has been very helpful. This is my first posting.

[Steve]

The idle creeping up as it warms up is a classic symptom of bad o-rings in the intake tubes. You need to replace them before you attack other "problems". In fact, once you replace the o-rings, you may find that everything else works a lot better.

But, to answer your question...
Can someone instruct me as to the proper settings for the air mixture screws on an 85 GS550L ??
First of all, how long have you had the bike? Sounds like it is not long. Would be best to start by checking the valve clearances. Unless you know the history of the bike, this is one maintenance step you really don't want to ignore. After the valves are checked, connect a set of gauges to synchronize the carbs. Once the carbs are synchronized, adjust the mixture screws, one at a time, listening for the highest rpm. Before adjusting the mixture screws, turn each one in to seat lightly, counting the turns, and record it. Start with the screws out about 2 turns from lightly seated. Once you have the highest rpm from each screw (and have adjusted idle speed back to normal), check the synchronization on the carbs again. Might not have changed much, but you since you still have the gauges attached...8-[


.

[hikermikem]

Where are the o-rings located

[hikermikem]

I'm not very knowledgeable with carb terminology. Could you please expalin where these o-rings are located in the carb?? The only ones i saw when i disassembled it were on the screen (filter) thing associated with the needle valves. Are they inside the cylinder assy's?? I didn't take those apart.

Thanks for any help you can give!!

regards, Mike

[LeeGS550E]

The o-rings are part of the rubber intake boots that go from carb to engine. Pull the carbs out and then the boots can be removed by unscrewing the three phillips screws that hold them onto the head. You'll want to replace these screws with socket-head allen screws when you put them back on, so that you can get better torque. You can also test your boots right now by spraying some water around the boots while the bike is running. I had an erratic idle and did this test and found out my boots and o-rings needed replacement. When the idle changes when you spray water on there, you know something's not sealing.

[hikermikem]

Thanks, I found them on an exploded view of the cylinder head.

[Calvin Blackmore]

Wehn replacing you O Rings did you notice how the boots lined up to the intake ports?

On Mine they are not altogether lined up which would lead me to think they had warped over time.

You could of course dismantle you carbs and take a picture................for the good of the 83-86 550 nation..............

[hikermikem]

Let me think on that one - are there any particular carb images that are desired?

[Calvin Blackmore]

viewed directly into the intakes noting any overlap or misalignment

basically mine are on but appear to be a wee bit lower ( top to bottm ) thna they should be so that on the bottom you can see the head and on the top their is a lip where the intake manifold does not line up.


Anyone ever notice this misaligment? is it time for new boots or will they be the same is what I am wondering.

A dremel and a case of beer ( with eye protection ) may be in the works

[LeeGS550E]

Calvin,
I had good alignment on my old boots, but I replaced because they were not sealing well at the carb. I would suggest just replacing them. Yes, its expensive ($35 USD a piece from bike bandit), but its money well spent. If yours still seal well at the carb, I suppose adjusting them witht the dremel would work. Long story short, mine lined up fine.

[mortation]

Calvin,
I had good alignment on my old boots, but I replaced because they were not sealing well at the carb. I would suggest just replacing them. Yes, its expensive ($35 USD a piece from bike bandit), but its money well spent. If yours still seal well at the carb, I suppose adjusting them witht the dremel would work. Long story short, mine lined up fine.

The boots are much cheaper from flatoutmotorcycles.com. I just ordered all 8 carb boots.

[LeeGS550E]

The boots are much cheaper from flatoutmotorcycles.com. I just ordered all 8 carb boots.

Damn!

Thanks though, I'll check them next time.

[mortation]

Damn!

Thanks though, I'll check them next time.

Yea they were $17.66 for the crank case side and $7.53 for the airbox side.

[Calvin Blackmore]

sooo my god what an eye opener

I used to pour heavy ger oil over my head side boots to make em swell and cure any possible leaks


but witht he bik dismantled its easy to chekc this mysterious o ring boot issue

took one off and my god not only are the inlets distorted due to heat age ozone and spite on their part but

the o rings do not rise above the groove they sit in

they are therfore non sealing pulled one it was brittle and more like a flt gasket than a ring

sooooo

its order time for the boots and rings.

what a shock i thought it would be touch and go an iffy thing if boots went but it seems that these are as disposable as sparkplugs and other consumables.

definitely an eye opener any runnign problem involving rich lean conditions would be traceable to this weak link.

to think of all the long term low level damage from elevated head temps due to a variable lean mix.

I am apalled and sufficiently chastened to open my wallet. Anyone with quirly running conditions would be well advised to do the same as metal on metal ssealing in an area that experiences sush a wide range of ambient temps is......................


buy some boots

[Zooks]

Huh???????????????? English version?