Hello, 

So me and my boy are having some issues with our project. 81 dt100. So the carb on it was pretty nasty looking, been outside for almost 18 years, so I decided to buy a carb off Amazon hoping that would at least get us running and idling. But once installed the carb immediately started leaking from the vent hole on the intake side of the carb. So today while at work I cleaned up the original carb the best I could by soaking it in our parts cleaner and running carb clean through all passages and blowing air through the passages and main jet. Came home installed carb and same thing, fuel coming from vent intake side and overflow hose. Float seem to be working when I had it apart but no luck. So my question is. Where can I find a good rebuild kit for this carb? And also our fuel tank I cleaned as well and found pin holes, at least 4 or 5. Should I try to fix or should I be looking for a new fuel tank? If so where? 

Any help would be appreciated!

Thanks! 

Could be that the needle valve is sticking - see item 4 on the attached. It should free up with a good, targeted clean.

Yamaha DT100 1981 ( USA CARBURETOR - buy original CARBURETOR spares online (cmsnl.com)

It might be possible to repair the pin holes on the tank, depending on where they are. Brazing might do it, or there might be liquid metal type products that do the job. Some folks swear by lank liners, but the preparation has to be spot on for these to work.

If you need a replacement, try a wanted post on this forum and also fleabay. Obviously take care when buying a replacement, just in case that one leaks after de-rusting as well (take it from one who found this out the hard way! ).

 

I'd go back to the new Amazon. albeit Chinese carb & should be an easy problem to find the flooding fault. Did you have the bowl off before fitting the carb or just bolt it on. Should be ready to go out of the box but doesn't hurt to look. Just check the floats are free to move & no rubbish from being packed & shipped has got into the float valve area.

Here's a link for carb kits Niche cycle carb kits there are some youtube videos on soldering pin holes in tanks, good luck with whichever way you decide to go.

Thanks for the information! 

I was just thinking, I have a cheap plastic fuel tank that I bought off Amazon to see if we could get it running. Is the flow from the tank to much for this carb by chance? The petcock is wider than the original tank. 

A correct working valve should still stop the flow, I would have thought.

I would think the same but both carbs doing the same thing makes me wonder if the tank I have is the problem. To much gravity flow?

if your little tank (or a 55 gallon drum or a swimming pool for that matter ) more or less has the same elevation with respect to the carb as the bikes tank, then the pressure to the carb is the same.

Well I will definitely be looking for a carb rebuild kit, wouldnt hurt anything. The boy and I got it running tonight for a little while but had to hold my hand over intake to keep it from running away on us. But found that the clutch is working properly so that's another thing on our list! 

"Well I will definitely be looking for a carb rebuild kit, wouldnt hurt anything."

Don't use the brassware in the kits! A lot of the original parts are still available from Yamaha or Mikuni.