Project: 1985 GS550ES

[Schweisshund]

I am going to attempt to build my own mannometer

I am going to attempt to build my own mannometer

I am going to see if I can get some tire pressure psi gauges - four 3 foot 1/4 inch hoses, and something I can use to place in the intake boot screw holes and attach to the hoses. I am also going to use a 2 litre coke bottle to put gas in, run tubing to the main gas line and plug the petcock vacuum hose as I adjust the carbs. Maybe then I will have solved part of the mystery of the high idling.

 

[LeeGS550E]

Since you have the dual carburetors, you can build your own carb balancing tool easily. I did a search and found an example on a BMW site since the BMW's are two cylinders. Its pretty basic: A 20' section of clear rubber hose with some liquid in it. You put each end of the hose on the vaccum port of each carb. Then you loop the center of the portion of the hose into a tall "U" shape and attached it to something (like a yardstick). This means that when the left carburetor pulls more vaccum than the right, the left portion of the "U" shaped water column will pull up, and vise versa for the right carb. When the carbs are balanced, the "U" shaped column of water will be level at the tops. I have some pictures at home of how I did mine. I'll post them later. Sorry, this is, once again, something hard to explain in writing.

I also learned on "Bill Nie the Science Guy" how to make a volcanoe out of vinigar and baking soda...maybe I'll start a different thread for that.:-D

 

[MelodicMetalGod]

I tried this and it didn't tell me anything, but my leak was on the vacuum hose.
Have you replaced your hoses with clear ones? The local shop just gave me a few short lengths of this to replace my old black ones. This will help you diagnose.
good luck
j

Yeah, I'm pretty much not gonna mess with propane. :shock:

Actually, I'm planning on getting new fuel and vacuum lines tomorrow.

Thanks!

 

[MelodicMetalGod]

I am going to see if I can get some tire pressure psi gauges - four 3 foot 1/4 inch hoses, and something I can use to place in the intake boot screw holes and attach to the hoses. I am also going to use a 2 litre coke bottle to put gas in, run tubing to the main gas line and plug the petcock vacuum hose as I adjust the carbs. Maybe then I will have solved part of the mystery of the high idling.

Four? I think we only need two since we can only adjust the 1&2 together against 3&4 together.

Intake boot screw holes? I don't understand...

I like the two liter "gas tank" idea.

PS: Is your Suzuki really a "CB" 550 E? (Check your signature)

 

[MelodicMetalGod]

Since you have the dual carburetors, you can build your own carb balancing tool easily. I did a search and found an example on a BMW site since the BMW's are two cylinders. Its pretty basic: A 20' section of clear rubber hose with some liquid in it. You put each end of the hose on the vaccum port of each carb. Then you loop the center of the portion of the hose into a tall "U" shape and attached it to something (like a yardstick). This means that when the left carburetor pulls more vaccum than the right, the left portion of the "U" shaped water column will pull up, and vise versa for the right carb. When the carbs are balanced, the "U" shaped column of water will be level at the tops. I have some pictures at home of how I did mine. I'll post them later. Sorry, this is, once again, something hard to explain in writing.

I also learned on "Bill Nie the Science Guy" how to make a volcanoe out of vinigar and baking soda...maybe I'll start a different thread for that.:-D

I'll definitely take a look at your own picks and any links you might have to the BMW setup. Thanks!

Vinegar + baking soda = volanco? Sounds more like an episode of Mythbusters.

 

[Schweisshund]

I have two motorcycles - the Honda carbs have a screw on each boot from the carb to engine that has to be removed then the vacuum hose is inserted and sealed - there are 4 on the Honda and yes, you are right dual carbs on the GS 550 so I would only need two vacuum hoses for the Suzuki. I should have explained I would be using this for both bikes.

The mannometer I saw the guy use on my honda when I had them synced was his own design - he measured the vacuum of each carb then adjusted the air/mixture screws on each carb to get it to idle correctly. There was just one screw that was out of sync by a hair that was causing it to idle erractlically. If I remember correctly, he had a gauge at the end of each hose that looked much like a tire pressure gauge (not the pen type gauges - the circular ones that has a needle) and set them all to 30 psi on the nose. I will do an internet search and see if I can find a picture of what I am trying to explain in words.

 

[Schweisshund]

Right column - 2nd pic down is a mannometer

Right column - 2nd pic down is a mannometer

I couldn't make it bigger without blurring it - but if you notice, there is a picture of a fire extinguisher too (in case anyone reads this thread and decides to use propane - lol).

 

[MelodicMetalGod]

I couldn't make it bigger without blurring it - but if you notice, there is a picture of a fire extinguisher too (in case anyone reads this thread and decides to use propane - lol).

A fire extinguisher (at LEAST one) s/b part of EVERY garage/work space.

Yeah, I've seen the manometers before. Just haven't ever laid hands on one. The http://www.carbtune.com/ looks like the best, but it's a bit pricey.

 

[MelodicMetalGod]

Pilot Screws 1 & 3 Still Stuck - I Give Up!

Pilot Screws 1 & 3 Still Stuck - I Give Up!

Well, not really. Today I took my carbs to a local custom shop that swore that they had the tools, time, experience and patience to either get the stuck pilot screw out or at least not destroy the carbs while trying.

I have no carbs and therefore no bike until at least Tuesday. Until then, I'm crossing my fingers and toes. [-o<

 

[MelodicMetalGod]

Pilot Screws 1 & 3 - Still Stuck

Pilot Screws 1 & 3 - Still Stuck

Well, just heard from the custom shop today. Seems they don't think they can get the screws out without destroying the rest of the carbs. Man does this suck. I've got a great bike that runs, but I can't tune the thing because of two little screws that never should've been screwed with in the first place.

If you have any suggestions on how to get these things out, please let me know. Thanks.

 

[LeeGS550E]

I'm sorry to hear that. You're so close. Maybe head for ebay...

Did you install the new intake boots and o-rings, and did this effect your idle problem?

Also, you have tried heating the area of the carbs around the screws, right? Heating and cooling cycles will cause the different metals to expand and contract, and might break the bond. Just another idea.

Hope you can work it out.

 

[Schweisshund]

Hey there,

Lee sent me a replacement carburetor I purchased from him because, oddly enough I was having the same exact problem with my carburetors that you are having with yours. I had two jet screws that were stripped. When his carburetors arrived, I went about extracting the two jet screws very very carefully and did so with success and replaced the two stripped screws with two from Lee's carb. Yes, that means I have two extras. See if we have the same carburetor (I have a 1983 Suzuki GS550E).

Ok here is what I did - very very carefully. I got an electric drill and titanium bits. I got the smallest bit I could fit in the electric drill and tried to drill a hole in the stripped jet screws. At first, it seemed like I wasn't going to be able to. I used compressed air to clean out the shavings. This requires some patience as the steel on those screws is pretty hard. Anyway. I was able to drill a hole eventually about a 1/4 inch deep in the center of each screw. I then got the smallest screw extractor and hammered it into the hole I drilled. I then saturated everything (once the extractor was firmly in place) with PB Blaster. I waited then got handle lock vise grips and clamped down on the screw extractor and very sloooooooooooowly (emphasis is very important) unscrewed the stripped jet screws.

 

[Schweisshund]

pictures of stripped jet screws (one with attached extractor)

pictures of stripped jet screws (one with attached extractor)

 

[Schweisshund]

Carburetors I got from Lee

Carburetors I got from Lee

 

[MelodicMetalGod]

I'm sorry to hear that. You're so close. Maybe head for ebay...

Did you install the new intake boots and o-rings, and did this effect your idle problem?

Also, you have tried heating the area of the carbs around the screws, right? Heating and cooling cycles will cause the different metals to expand and contract, and might break the bond. Just another idea.

Hope you can work it out.

I have installed the new boots and o-rings that you sent, but I haven't had the carbs back on yet because I've been trying to get the pilot screws out.

The custom shop tried heat to no avail.

I may have located another mech that will take a shot at removing the screws... IMHO, what is needed is the right tools. I see NO reason why a competent machinist with the right tools can't drill into these screws and attempt a backout/ez out. Sure, the backout/ez out may break, but nothings lost if it does since the screws are already stuck, as long as the drilling doesn't destroy the carb body. If a drill press is used and the carb is jigged well, avoiding damage to the carb body should a non-issue. I'd do it myself, but I'm trying to avoid buying a drill press, bits, etc. for what I figure will be a one time job.

 

[MelodicMetalGod]

Hey there,

Lee sent me a replacement carburetor I purchased from him because, oddly enough I was having the same exact problem with my carburetors that you are having with yours. I had two jet screws that were stripped. When his carburetors arrived, I went about extracting the two jet screws very very carefully and did so with success and replaced the two stripped screws with two from Lee's carb. Yes, that means I have two extras. See if we have the same carburetor (I have a 1983 Suzuki GS550E).

Ok here is what I did - very very carefully. I got an electric drill and titanium bits. I got the smallest bit I could fit in the electric drill and tried to drill a hole in the stripped jet screws. At first, it seemed like I wasn't going to be able to. I used compressed air to clean out the shavings. This requires some patience as the steel on those screws is pretty hard. Anyway. I was able to drill a hole eventually about a 1/4 inch deep in the center of each screw. I then got the smallest screw extractor and hammered it into the hole I drilled. I then saturated everything (once the extractor was firmly in place) with PB Blaster. I waited then got handle lock vise grips and clamped down on the screw extractor and very sloooooooooooowly (emphasis is very important) unscrewed the stripped jet screws.

Thanks for the reply. I'm pretty sure that we've got the same carbs on our bikes. I've actually got a couple of battered sets of the carbs that I can pull replacement screws from, but I'll keep your offer in mind.

I may yet follow your lead, but since I've not been able to get the job done with my modest collection of tools I've been hoping to hire the job out to an "expert" that has the best tools and experiece.

I've done the PB Blaster, as did the custom shop, to no avail. The PB Blaster just sits in a pool on top of the screw...doesn't seep in AT ALL, and that's after sitting for over a week.

My next try: I've got another local mech on the line that says he's got his own machine shop... Wish me luck!

 

[Thehotbeast]

I had the same problem with one jet screws on my 84GS750... drilled a hole in the screw and used a screw extractor.... need to be very gentle.

My bike had the same symptoms as yours, white plugs and high idling... was running lean. I have adjusted it using the highest RPM method and now it idles perfectly. My adjustments are 2 1/2 turn out on each carburetor.

Good luck.

 

[MelodicMetalGod]

Well, picked the carbs up from mech # 1 (at a custom shop) and drove 1/2 mile down the road and dropped 'em to mech # 2 (at a HD/Buell shop). Hopefully he'll be callin' with good news by weeks end. [fingers, toes and eyeballs crossed! :shock:

 

[Schweisshund]

If no luck - mail them to me :-D After having already done this to the exact same set of carburetors, I know how to do it. Hopefully the Buell mech knows what to do. Good Luck.

 

[MelodicMetalGod]

Bad news. Just got a call that my carbs are ready for pickup - with the two screws still stuck!!!!!

aaaaaaaaaaaaaaaAAAAAAAAAAAARRRRRRRRRRRRRRRRGGGGGGGGGGHHHHHHH!

Guess it's up to me. Well, at least I know that I didn't overlook the option of shopping the work out to a pro.

I think I'll pick up the carbs and drop by sears for the needed tools. Hopefully I don't destroy an otherwise perfectly good set of carbs. Wish me luck!