‘75 GT550 carburetor questions

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pgb123
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Re: ‘75 GT550 carburetor questions

Post by pgb123 »

Alan H wrote:Slowly, thoroughly, and eventually. Horrible isn't it?
There’s got to be a better way. Acetone?
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Alan H
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Re: ‘75 GT550 carburetor questions

Post by Alan H »

Put it in the freezer for an hour and when it's brittle, tap it away carefully.

Do this when your wife is out!!
Think of how stupid the average person is, then realise that half of them are more stupid than that.
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dorT500
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Re: ‘75 GT550 carburetor questions

Post by dorT500 »

pgb123 wrote:........Hoses survived u/s bath.......
I agree with Sportston....I'd install new fuel lines if I were you..... unless you want to take a chance of this happening on the road. Fuel pouring out the external vent and overflow tube.
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Found this lodged in the needle valve..... :shock:
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I think it is a tiny chip of fuel line that must of broken off inside when I was cramming a probably older than I remembered fuel line onto this carb at one time.
Last edited by dorT500 on Sat Sep 01, 2018 1:04 pm, edited 1 time in total.
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Re: ‘75 GT550 carburetor questions

Post by sportston »

The dishwasher fluid might work ok. Or you could use proper parts cleaner solution, if it doesn't work well enough. Yes, always immediately after the bath you should rinse and wd40. Otherwise you can get small bits of corrosion blooming in the hard to reach parts of the carb, just waiting to clog up your new jets.
And yes, the black goo is a pain in the posterior that every gt550/gt380 owner with that type of carbs has to confront. Like Alan says, it takes perseverance. I used various fluids to help clean it up on my carbs, petrol, paint thinners, meths, carb cleaner, brake cleaner... you name it I tried it. Several bottles and quite a few rags later it was gone! Speaking of rags....I almost lost mine. Lol
Yes do replace the hoses. It will save you lots of time and hassle later. And while you are doing it, fit an inline fuel filter. A filter is essential on an old bike. You have three possible opportunities for dirt to clog a jet, it is well worth eliminating that possibility.
Good luck buddy. You're heading in the right direction. Keep at it.
pgb123
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Re: ‘75 GT550 carburetor questions

Post by pgb123 »

Again, thank you all for the help and the encouragement. Because the carbs weren’t in such bad shape, the dish detergent worked well. Nail polish remover seems to be working to get the melted rubber off the parts. I didn’t have acetone on hand so I improvised. Between that and the sink, my wife’s none to pleased with me right now.

I will replace the hoses. Am I correct that the fuel hose is 1/4” inner diameter? What about these other hoses? And what are they for, btw? They were just zip tied together and not attached to anything on the other end.
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pgb123
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Re: ‘75 GT550 carburetor questions

Post by pgb123 »

Anyone?
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Evans Ward
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Re: ‘75 GT550 carburetor questions

Post by Evans Ward »

The black one is the float bowl overflow hose. Your other carb should have one too. The yellow/ clear one.... I'm not sure on it? Could possibly be vacuum or vent hose but will defer to a guru here.

How are you making out with the cleaning? Do one carb at a time so you don't get confused or mix up any parts.
1976 Suzuki GT750 (Maui Blue), 1972 Kawasaki H2 750 Mach IV (Candytone Blue), 1984 Yamaha RZ350 (KRR- Yellow/ Black).
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dorT500
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Re: ‘75 GT550 carburetor questions

Post by dorT500 »

pgb123 wrote:Anyone?
uh oh....be careful who you ask for. :) I'm an anyone. :) I'm no GT550 expert...
pgb123 wrote:....I will replace the hoses. Am I correct that the fuel hose is 1/4” inner diameter? What about these other hoses? And what are they for, btw? They were just zip tied together and not attached to anything on the other end.
The fuel line sizes vary on that carb bank :arrow: https://www.partzilla.com/catalog/suzuk ... etor-gt55o" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; You might take the various sections of hose to an auto parts supply....may have some of them close and may have an exact size for you. Other than that you can try online or walk in a motorcycle dealership parts department BUT I always ask parts department countermen to beat the online prices of parts I'm looking to buy (I'll have a print out for them) or I may settle with them just matching the price if I have to. Yes, you will pay tax but no shipping....at least, that has been my experience. Their price ranges from MSRP to a 'he's no dummy' price.

Anyway, maybe these pics off the net will help some on fuel line, the 'use to be clear' overflow to the ground lines, vacuum lines and reassembly of the carb bank, etc.

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pgb123
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Re: ‘75 GT550 carburetor questions

Post by pgb123 »

Thank you for the pics. Those are helpful. I’ve actually found a few threads on here that have specific references to where the hoses go and which are vents, overflow and fuel. I’ll post them when I’m able. Looking at the Partzilla diagram, the parts are listed with dimensions. For instance, part no. 09355-45855-600 HOSE is listed with the following dimensions: (4.5X8.5X600) | 45x8x75. Does anyone know if one of those measurements is the inner diameter? Is this mm and cm?

Or, better yet, does someone happen to know the inner diameter of each of the hoses I’ll need?

Thanks!
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Re: ‘75 GT550 carburetor questions

Post by pgb123 »

Evans Ward wrote:The black one is the float bowl overflow hose. Your other carb should have one too. The yellow/ clear one.... I'm not sure on it? Could possibly be vacuum or vent hose but will defer to a guru here.

How are you making out with the cleaning? Do one carb at a time so you don't get confused or mix up any parts.
From my research, you are correct. The clear/yellow hose is a vent. I've almost gotten most off the goop of the parts, though it remains in some crevices and the threads of the valve shaft. This stuff is really tenacious! Since I've had to wait for some parts to arribe in the mail, it's given me time to keep at the cleaning.

I've kept the three carbs, parts and valves in separate labeled baggies. Hopefully, I haven't mixed anything up.

Thanks for the help!
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dorT500
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Re: ‘75 GT550 carburetor questions

Post by dorT500 »

pgb123 wrote:.............. For instance, part no. 09355-45855-600 HOSE is listed with the following dimensions: (4.5X8.5X600) | 45x8x75. Does anyone know if one of those measurements is the inner diameter? Is this mm and cm?
Or, better yet, does someone happen to know the inner diameter of each of the hoses I’ll need?
It may not be too clear but with a little experience you can read through them. :) Might be a little typo action going on over there also. Until somebody here can rattle off the sizes you need, have a look at the site below........... I am not suggesting you buy from the vendors I post. PartsZilla prices are good but I think the shipping and handling is a little higher than most...not sure. Just use them as a guide to match up line buying by the foot price and matching the size up as close as you can from auto supply stores, other online sources, etc. and cut the various lengths you need out of it. Take a carb along with you it you want to try an auto parts supply and 'try on a few'. :) while the different lines are still on their bulk rolls. Look at their fuel injector line also....usually a little thicker wall than carburetor fuel line but that's OK.

The measurements you have been looking at are in mm First one is the inner diameter then the outer diameter and then the length.

This website will probably be a little clearer for you. Click on the part number and it will give more details including part number changes and clearer measurements.....again....I offer this just as a guide to narrow down the inner diameter sizes so you can shop it in longer lengths you can cut to suit your needs. :arrow: https://alpha-sports.com/suzuki_parts.htm" onclick="window.open(this.href);return false;"

Here is the part number for Ref. #80 you used as an example, a new part number as a matter of fact.

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pgb123
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Re: ‘75 GT550 carburetor questions

Post by pgb123 »

Excellent! Thank you for the clarification. That makes things much easier!
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dorT500
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Re: ‘75 GT550 carburetor questions

Post by dorT500 »

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pgb123
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Re: ‘75 GT550 carburetor questions

Post by pgb123 »

Can anyone tell me what this screw is and how tight it should be?
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Re: ‘75 GT550 carburetor questions

Post by GTandcbr »

That is the throttle valve sight hole used when setting the oil pump. It should be tight and have a gasket underneath.
98 carb Blackbird and GT550j
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