Suzuki 2 Strokes

Hello!

I have a T500, and I want to buy some carburettor spares, but I am unsure which model of carburettor I have.

The year on the reg. certificate says 1977.

This is a picture, does it help?

I am not a T500 man, but that is not a 77. The T500 changed to GT500 in 76. Least wise they did in the states. There should be a plate on the right side of the steering neck behind the headlight that would show the month and year of manufacture. If it is August or later, it would most likely be the following year model. My 75 GT550 was manufactured in 8/74. If the plate is missing, the frame number is stamped to the frame in the same area. You could do some cross reference from that to find out what you actually have.
It would be nice if you included your location in your profile. Nice ride!!

But where the carburettors changed for the later models? I am trying to order a needle/seat assembly.

If you search this site you will find a link to a spreadsheet listing T/GT500 frame and engine numbers (actually, to save you some time this is the link viewtopic.php?f=8&t=4639&start=15#p111421" onclick="window.open(this.href);return false;) . That will allow you to identify your model year. Then go to any on line parts fiche and look up the part number of the carb for that year - its likely a 13202-15313 for the left and a 13201-15313 for the right - using that number, most on line parts fiches allow you also to search by part number and then give you a list of models to select from.

I suggest you double check it yourself, but I think you will find that the same carbs were used on 1973 through 1977 models.

I don't know anything about the carbs. Looking at the model history, both the T500 and the GT500 were produced in 75. The GT500 replacing the T500 mid year or so. I know it's not a GT500 because they had disk brakes in the front. Yours most resembles the 72 and 73.
There are a million 500 owners on this site, and some know everything and then some about them. Be patient. I'm sure others will chime in.

Not a 72. Late model style carb intakes, and no bling for the oil tank.

No factory tank decals, so it has been repainted. Without frame/engine numbers to go on, it is somewhere 1973-1975.

Carbs for those years don't really change much. Basically the same body, with the same jetting in it.

Suzuki Service Bulletin 6-9 will give the details.

Pick up the needle/seat from Dennis Kirk. Paid $35 for the pair. Genuine Mikuni, work perfectly on my bike (with a marginal petcock). Much cheaper than what Suzuki will hit you ($40 each?)

Mikuni VM28/163- Needle and Seat Size 2.5

and no bling for the oil tank.

What's a bling?

ConnerVT, would you happen to have the Mikuni number? Ordering from the states is very expensive for me

Sorry, I got it now

Coyote wrote:

and no bling for the oil tank.

What's a bling?

The bright shiny stuff. Like all the gold chains and rings you see on rappers, or Mr.T.

1972 was the only year with these side covers.
1972 was also the last year that the intake between the carbs and cylinder was the short, one piece part. In 1973, they changed the cylinder porting, and went to the 2 piece intake. Changed the jetting significantly also. lasse bike has the longer intake, compared to this 1972:

On the carburettor it reads the number:

153
13

This seems to be for a VM28/163, can I still use it?

The carbs on the Suzuki (as well as Kaws and others from that era) were built to the factory's OEM specs. The carbs you have are basically VM32 spigot bodies.

From the Sudco catalog, the part number is VM28/163 :
When I pulled apart the carbs on mine, the seat was stamped with 2.5, as well as the Mikuni logo (a square in a square):
Now, it could of been replaced with the wrong part somewhere along the line, but it has been working well for me. Much better than the Keyster part I tried, which was totally the wrong part.

The 2.5 references the diameter of the fuel opening, and the important thing is not to be too small (potential for low fuel level in bowl during WOT).

When you pull yours apart, you can see what you have installed.

Changed the needle/seat assembly. Spare part was also with a metal tip. Still overflows.

Is it possible to get one with a rubber tip?

Go to http://www.psep.biz/store/mikuni_needle_seat.htm" onclick="window.open(this.href);return false;

Part no ADVM2851125 Viton tip

Is it overflowing when the bike is running or when its parked?

If it overflows when its parked, then you probably have petcock problems. This seems to be pretty common.
Pull one of the fuel lines off the petcock when the bike is not running. It should not drip.

If it overflows when running, you might have a bad float. Could be either a sunken/leaking float, or a float that is dented.

All three of these problems happened to me.

Petcock leaked so badly on my GT250 that gas dripped out of the exhaust. Problem was solved by replacing the petcock.

Had a sunken float on my T500 at the beginning of this year. Right cylinder didn't run right. Right float was heavier because it contained gas. Problem was solved by replacing the float.

When I got my T350 it ran erratically. Floats were dented in by the PO. Replaced the floats & it runs much better.