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Where to start?

Posted: Sun Aug 16, 2015 6:30 pm
by Red&Gold
Hi all, new to this forum and 2-strokes as a whole. I'm a Harley guy at heart but the Ol' lady has a 73 GT550 that needs some lovin... I'm not above grabbing a metric wrench.

Bike was a runner but has been sitting for s few years. This machine is a bear to start and doesn't want to stay running once it warms up. What's the consensus on where to begin going through this machine to bring it back to a one kick start bike?

Thanks in advance,
Andy

Re: Where to start?

Posted: Sun Aug 16, 2015 7:38 pm
by sbaugz
Carbs for sure is the first thing you should do.

Re: Where to start?

Posted: Sun Aug 16, 2015 7:55 pm
by Coyote
Carbs off. carefully clean all the jets. Use carb cleaner and compressed air to clean out the passages. Drain out the horrible old fuel and add fresh. Clean the plugs and the points. If fuel was left in it, you can bank on the jets being clogged. You have ethanol fuel to thank for that. Ethanol likes to coagulate in the jets. DO NOT use compressed air on an assembled carb. It will collapse the floats

Re: Where to start?

Posted: Sun Aug 16, 2015 8:24 pm
by Red&Gold
I assume the little boots that are missing on the carbs are fairly important? Is there a recommended retailer for parts for these machines?

Re: Where to start?

Posted: Tue Aug 18, 2015 9:24 pm
by Coyote
I'm surprised no one is responding here. What year is the 380?. If you have a 74-77, yes those boots are important. They are still available, but they are stupid expensive. Approx.$25 EACH. One thing I think is important to point out is the battery. These bikes have no magneto. 100% battery excited ignition. This makes the condition of the battery of utmost importance. If the battery is off the mark, the bike won't run right and leave you wondering why. If the battery is old, you need to invest in a new one unless the old will take and hold a charge. If it's a lead acid battery and allowed to fully dead, they won't come back.
So have you done anything? How long has the bike been ignored? Sadly that's the worst thing for them and it takes a lot of time and money to even get them close to what they once were. Many many parts are still available, but the prices seem to go up weekly.

Re: Where to start?

Posted: Tue Aug 18, 2015 11:52 pm
by Alan H
On a 73 GT550, the carbs should be separate units. The 74 on have three carbs linked on a manifold.
Can you confirm what you have and a couple of pics would be helpful too.
I'm currently running a late 72 GT550 (ex ) US bike which is actually a 73 'K' model
Have a look on ebay for a parts catalogue, they have exploded views of all the components and are really helpful.
Coyote is right regarding the battery, it must be good or the bike just will not run well (or at all) - and the 550 should be a 1 press starter, the kicker is for looks!

Re: Where to start?

Posted: Wed Aug 19, 2015 1:21 am
by Glyn.G
Coyote wrote:I'm surprised no one is responding here. What year is the 380?. If you have a 74-77, yes those boots are important. They are still available, but they are stupid expensive. Approx.$25 EACH. One thing I think is important to point out is the battery. These bikes have no magneto. 100% battery excited ignition. This makes the condition of the battery of utmost importance. If the battery is off the mark, the bike won't run right and leave you wondering why. If the battery is old, you need to invest in a new one unless the old will take and hold a charge. If it's a lead acid battery and allowed to fully dead, they won't come back.
So have you done anything? How long has the bike been ignored? Sadly that's the worst thing for them and it takes a lot of time and money to even get them close to what they once were. Many many parts are still available, but the prices seem to go up weekly.
Ok Coyote,
Now you have me worried as my 77 380 has had a split rubber boot on the centre carb for over a year now. I've done over 1,500 miles with it like this with no adverse trouble. I've seen pictures of these bikes with no boots on at all so what do they actually do. I thought they were just dust covers.

Re: Where to start?

Posted: Wed Aug 19, 2015 1:32 am
by Alan H
They stop air getting in the carbs and giving a weak mixture.

Re: Where to start?

Posted: Wed Aug 19, 2015 2:17 am
by Glyn.G
Alan H wrote:They stop air getting in the carbs and giving a weak mixture.
Time to order a new one then Alan .

Re: Where to start?

Posted: Wed Aug 19, 2015 8:29 am
by GTandcbr
http://www.ebay.co.uk/itm/NOS-suzuki-gt ... 5b16ef868d" onclick="window.open(this.href);return false;

Re: Where to start?

Posted: Wed Aug 19, 2015 8:55 am
by Coyote
I missed that it is a 73 and my feeble mind saw 380. not 550. If it is in fact a 73, he doesn't need any of those high dollar boots. He must be talking about the little rubber caps where the cables enter on the carb tops.

Re: Where to start?

Posted: Wed Aug 19, 2015 10:17 am
by GTandcbr
http://www.ebay.co.uk/itm/NOS-Suzuki-Du ... 2c5ce281fd" onclick="window.open(this.href);return false;

Re: Where to start?

Posted: Wed Aug 19, 2015 10:43 am
by Alan H
Coyote wrote:I missed that it is a 73 and my feeble mind saw 380. not 550. If it is in fact a 73, he doesn't need any of those high dollar boots. He must be talking about the little rubber caps where the cables enter on the carb tops.
Yes. The thing is, with different models, you got them just before us, so a 73 bike might be a 74 model. The GT550K I have is ex-US and was made in August '72, so is technically a J, but configured as a K, and probably sold to someone in early 73. Pity I didn't get any US paperwork or details other than import documents when I bought the newly imported bike back in 2011.

For Red&Gold's benefit, there were several different types of carbs on 550s, separate carbs were either Hi top (usually 73 K model) or Lo top (72 J model) - but not always!! -, and then they were linked in a bank but changed slightly over the years as regards jetting and some small parts.

Don't you just love them?!

Re: Where to start?

Posted: Wed Aug 19, 2015 12:08 pm
by Coyote
I'd love it more if I could see it. We really need a pic

Re: Where to start?

Posted: Wed Aug 19, 2015 10:28 pm
by Red&Gold
Ok, after a little more research... I believe this to be a '74 GT550. Hopefully that clears it up some. It won't let me post a pic right now, I'll try again tomorrow. I am talking about the vertical boots below the elbow boots on the top of the carbs.