Clean your carbs, boys!!

[FuzzButt]

Olav AAEN's Carb Tuning Handbook is a great way to understanding your carbs.

That's where I started. Jumped in with both feet. Learned a few things not to do. It is not all that difficult if you just put your mind to it.

For instance on my '97 the TM38's are off in about 5 minutes. I would not recommend turning or messing with the "Jet" like drain screw on the bottom of the float bowl if your has one.

From memory here it goes. (not everything you need to do but the important stuff so this list is not complete)

Grab your camera.

Take them out as a set (on the rack). Remove the air box and loosten the boots. Unplug the throttle position sensor, unscrew and remove the throttle cable. Unclamp and gently pull off the fuel lines from the pump. Unscrew the boots at the engine side of the carburetors. If you have heated carbs there will be a black hose going into them from a valve on the head. I'd just clamp it off and then undo the hoses at the carb on each end. They should be free from the motor and ready to remove.

Purchase a gallon size container of carburetor cleaner as well as a spray can of it. Have a clean surface to work on. Wear safety glasses! I would also wear nitril gloves if you have them.

Now your ready to clean. Grab your pencil and write down anything you do as you clean it. For instance if you remove something count the turns it took to remove it. Until you get the hang of it you should take notes.

I start at the bottom and work my way up. So flip them upside down and carefully remove the float bowl screws. You might need a impact screwdriver if they are not easy to turn.

Crewchief wrote up a tech article on the tech pages. http://www.totallyamaha.com/snowmobiles/aaTECH/carbs/cleaning_carbs.htm is the direct link. There are great pictures in there that will help you identify what is what and where to clean. I don't know if I would go as far as removing the cables at the handlebars. I've always figured the less you mess with the less you can make a mistake.

I would also dip anything I remove especially the bowls in the gallon container. If they are really dirty it is going to take a while.

Now the most important part. Do one carb at a time.

When your done and got everything back on remember the carbs are empty. It will take a bit of pulling it over to refill them before it will start. Right after it fires up turn it off and check for leaks.

Once your done sit back and admire your work. It is a nice feeling to have that you now know you can do this yourself. When you get real good you can field strip one on the trail. That is real fun.

 

[FuzzButt]

Oh ya forgot to say there are 2 Carburetor cleaning tip links. Both are good. Only the one I direct linked to has pictures.

Check out all the info on the tech pages. See totallyamaha.com (link is at the bottom of this page) and look on the left menu list for tech pages then select snowmobile. The carburetor stuff is in the Engine section.

 

[snomofo]

A little trick I learned years ago o-hauling automotive carbs for a living is to loosen the bowl screws one turn and using the plastic handle of the screw driver, tap the bowl at the corners to break the gasket away from the bowl thus saving the gasket for reassembly. Nothing worse than tearing the gasket and not having a replacement.

This is very important when doing this on the trail after a rookie and his barrowed sled dies in flight. In this case, pine needles work well for cleaning a plugged main.