'01 ZR500 won't start. Fuel dripping - Snowmobile Forum: Your #1 Snowmobile Forum

tmikula54871 · 12-29-2012, 09:07 PM

I'm helping my brother work on his '01 ZR500 Carb., and we could use some help from you all please.

Last season it ran perfectly (what little it had to run). Last week he went to start it for the first time of the season and it will not fire. When we spray starter fluid in the cylinders through the spark plug holes it will fire on that but will quit as soon as it burns out.

We then noticed that gas was pooling in the bottom of the belly pan and found that there is a gas line coming out of the bottom of each carb that gas runs out of when we try to start it. Aren't those the sediment collection tubes and should be plugged?? Another thing we noticed is that the fuel line going from the fuel pump to the carbs drains basically empty when we stop pulling the recoil. There's no back pressure holding fuel in the line and you can just watch it run out. That doesn't seem right to me, is it??

Thanks so much in advance for your help!

**kccats** · 12-30-2012, 05:48 AM

Did you have the carbs off and clean them? Then the fuel pump, and replace all the fuel lines!

**RJ Gleason** · 12-30-2012, 05:59 AM

Cat did not use sediment tubes, but many of the carbs did have over flow vent tubes.
Have you cleaned the carbs?
Make sure that the needle valve is sealing?

tmikula54871 · 12-30-2012, 10:45 AM

I had sediment tubes on my older Cats so I thought that would be it. I have never cleaned carbs before. I'm no mechanic and I'm a little scared of messing around with the carbs on the ZR or any other higher performance machine. I've been told they are pretty sensitive. I'll look in the sticky thread about cleaning carbs and maybe we'll give it a shot. Although it did run well last year for him (it was the first year he owned it), he did complain about it starting hard, so maybe they were in the process of getting dirty then. Is there any way to check the needle valve without tearing everything apart?

Thanks a lot for the help!

**RJ Gleason** · 12-30-2012, 11:10 AM

Just remove the carbs, turn upside down and remove bowls, the with a short piece of fuel line, blow into the inlet and move the floats. If the valve is working right, it will seal when the float arms are parallel with the carb bowl flange.
There is also the possibility that the floats are saturated and need replacing.

tmikula54871 · 12-30-2012, 11:13 AM

I looked at the carb cleaning section of the "how to" section but it only shows instructions for the round slide carbs. I don't know what the differences are between the round slide and the flat slide carbs but this machine has the flat slides. They look very different. Does anyone have instructions for cleaning the flatside carbs?

Thanks.

tmikula54871 · 12-30-2012, 08:01 PM

Can anyone help with instructions for cleaning the flat side carbs?

**RJ Gleason** · 12-31-2012, 09:06 AM

Basics are the same, primary difference will be that flat slide carbs may have an air and fuel screw.

**BC_Dan** · 12-31-2012, 10:10 AM

I posted some info on cleaning the TM38 rack carbs in the Snowmobile How To section. It may be of assistance.

http://www.snowmobileforum.com/engin...yle-carbs.html

tmikula54871 · 01-01-2013, 11:13 AM

Thanks for all your suggestions. It did indeed turn out to be sediment tubes that needed to be replaced. He went and bought new ones, put them on and the problem was solved. It runs great now and doesn't leak gas. So RJ Gleason take note, they DO use sediment tubes on Cats.

Thanks again.

**RJ Gleason** · 01-01-2013, 05:09 PM

Must just be on the flat slides then, never saw any on a round slide carb in a Cat.