1972 Suzuki T500 Restoration

[Buzzthekid]

Aight so new rider here, my grandfather gave me his old 1972 Suzuki T500 and I wanted to restore it and let it be my intro to driving on two wheels just as it was for my mother and grandfather.

Unfortunately I don't posses hardly any motorcycle knowledge (I can and have worked on mine, my families, and buddies cars, just not bikes)

The main issues I am presented with are:

The petcock does not deliver enough fuel to the carbs even after cleaning (I have to prime it then it'll die moments later)

There is an oil leak however uncertain its origin

The bike will stall with no throttle

I've looked over the basics (Oil, fuel, power delivery) and have gotten her to start with a little throttle. What else would I need to inspect and potentially fix before she is (in a sane sense) road worthy?

No photos yet, haven't gotten em from the phone.

[Guest]

No idea but welcome along and looking forward to pics. Love a good resto thread

[Mississippi Bullfrog]

Are you sure it’s the fuel cock rather than the float needles. Bikes that have been laid up for a long time often suffer float needle issues. Old fuel sets into a hard varnish, the best thing I’ve found for shifting it is for powerboat engines. Quicksilver Powertune, Johnson’s and Evinrude make similar products.

The stalling with no throttle may be the carbs needing really sorting or as simple as the idle adjustment is out.

Oil leak...no way of telling without photos.

You’ll need new tyres of course. Thoroughly check the suspension, brakes, all bushes and bearings, hydraulic lines and fluid.

A nice project and an ideal way to learn.

[oldgrump]

Hi and welcome, The fuel tap on the T500 is vacuum fed, so two pipes go to the float bowls and the other goes from back of carb near air filter hose to vacuum unit on tap. you can check vacuum unit by disconnecting pipe from carb side and sucking on it to see if fuel comes out of other two pipes.

Hence could be why you only getting fuel out of prime.

Another problem is if this pipe missing you will be sucking neat air into carb, making running and starting problems.

There is also two large screw's on either side of carbs, these are the tick over screw's, so once you get it running, screw them in slowly to see if you can get it to tick over.

As [mention]Mississippi Bullfrog[/mention] said check tyres, and on the T500 the brake shoe's, these can de-laminate if been stood a long time. Should be cable's brakes so check cables are not frayed.

And worse scenario is the fact that the crank seals sometime dry out in the engine, if bike not been used or started for awhile, and can cause a lot of running problems.

But on a positive note they go for a lot of money in good condition

But parts are expensive! Do you know what model it is?

[Buzzthekid]

[mention]Mississippi Bullfrog[/mention] I've rebuilt the carbs and used excessive amounts of carb cleaner to clear them out, no way of knowing whether I have my idle correct or not.

[mention]oldgrump[/mention] I had an issue with that 3rd line coming off the petcock as it flooded the left carb and cylinder. I had to disassemble the petcock to clean the old gas out of the petcock. Is there something wrong on the petcock to cause it to overflow/flood the carb/engine?

Once im no longer deathly sick i can actively get photos and info off the bike for you guys

thanks in advance

[Mississippi Bullfrog]

If the left carb is flooding then it sounds like the float needle isn't working. Check the float itself hasn't filled with fuel.

[oldgrump]

Hi [mention]Buzzthekid[/mention] , the 3rd line is vacuum, or air only, it opens the diaphragm to let fuel from other two feeds. If you have fuel in that line, it sounds to me like the diaphragm has gone. Not sure if you can get replacement ones. You can still try to run the engine up by blanking off the feed at both ends.

ie a piece of pipe on carb end which is clamped so no air can get into carb. and pipe on petcock clamped again so nothing out that end. then if tap working on prime you should have constant fuel out of other 2 lines?

Try that, if like [mention]Mississippi Bullfrog[/mention] says you then have flooding in carbs then it's either stuck or holed float's or needle valves not shutting fuel supply into carbs.

But try that at first.

[Buzzthekid]

So this is the bike I'm working with

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My fuel petcock and carb setup (They do have overflow lines at the bottom of the carb)

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I can indeed run the bike on prime

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I believe the leak is at the bottom

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All in all she will run and idle right now, however the left carb is giving me additional issues.

[mention]oldgrump[/mention] I had extra tubing and pulled a vacuum on it and fuel did not move down the line, so i believe I fixed that issue.

[mention]Mississippi Bullfrog[/mention] I don't have much experience with carbs (much less bike carbs) is the float needle the one attached to my throttle cable inside the main airflow run that plugs the hole to my bowls?