T500R carburettor spec

[Monkey man]

Good evening all

I’ve recently acquired another Suzuki 500- this time it’s a 1971 R model which looks immaculate on the outside but unfortunately doesn’t run as good as it looks . It starts ok but then fouls the plugs and won’t run cleanly. Reading some of the history that came with it the previous owner seemed to be having issues with the carbs or experimenting with the carb settings. So before I dive in and take the carbs off I would like to know the stock spec for the various needles and jet sizes . Can anyone point me in the right direction

Many thanks

[jabcb]

T500s have two different types of carbs -- the float bowls are vented differently.
Early carb float bowls are vented internally and later are vented to the air.
The two types are jetted very differently.

So to start with you need to figure out which carb the bike has.
Carbs have a 5 digit number stamped on them — this is the second part of the Suzuki part number.
Find that and we can figure out which carb you have and what the stock jetting was.

The number likely is near the choke plunger or the carb-to-cylinder attachment.

[Monkey man]

Cheers - sound advice- I’ll see if I can identify which ones are fitted

[Monkey man]

At last - it took some finding but using a mirror and torch I found the numbers as suggested near the choke plunger

It is 15601 - so can anyone enlighten me on the specs for these carburettors?

Thanks

[jabcb]

OldJapaneseBikes.com has useful info:
carb history:
https://www.oldjapanesebikes.com/mraxl_ ... ms/page-72
manuals:
https://www.oldjapanesebikes.com/mraxl_ ... /index.php

Another site has Service Bulletins:
https://www.ozebook.com/compendium/techbuls/index.htm

Looks like you have the carbs for the 1971 T500R model year.
So for jetting look at Service Bulletin Specification-6.

Does your bike have the original air box & exhaust?

[Monkey man]

Thanks everyone- I now have the spec for these carburettors
However I have noticed there is about a half inch play in the cables at the carb tops and no amount of adjusting the play at the throttle end or carb tops will take up the slack.

I presume the throttle cable is the correct part and perhaps even original ( all cables on the bike are grey ) . Could it be the routing of the cable is incorrect and could re routing take up the slack ?

I had similar problems with my previous t500m and it was resolved by fitting a second hand original cable but these are hard to come by

[jabcb]

Are the slides operating correctly? From fully closed to all the way open?

[Monkey man]

Yes - double checked they were inserted correctly with the cut out running down the throttle body engaging with the lug in the carb so that the top of the throttle is about three quarters of an inch below the carb top . So I’m guessing it won’t go any lower.

[Monkey man]

Hi guys- I’ve got to the bottom of the excess play in the cables - I should have known better- on checking the throttle bodies they were the wrong way round so turning them 180 degrees saw them slide into the carb bodies another inch or so . Now I can re- check the bikes running following adjustments made to needle settings