fuel issue??

[touchofgrey]

So I bought this olympic 335 ski-doo I can't find a year on it, but the owners manual says it is a 70-71 model. It had no spark when I got it, but I fixed that, it will start and run like a champ when I give it a drink of fuel down the spark plug, but it won't continue to run on it's own. It looks like the fuel pump is on the bottom of the carb. When we took the fuel line off at the tank and kinda force fed it some fuel, it would run, but I had to keep the rpm's fairly high. Any help will be appreciated. Thanks, D.

 

[Snow Flake]

The needle is probably stuck in the seat.. In the old days that happened every fall when we tried to start the first time of the season. From the bottom of the carb take out all the screws going up through those several round plates. That is the fuel pump. Take the needle out and check the rubber tip. If it is not smooth and pointed sometimes we polished it with commet or some other abrasive clenser to rejuvinate it. Check all the gaskets and diaphrams while its apart.

If you take the carb off the engine notice there is a small hole that runs through the mounting plate and gasket into the engine crankcase. That supplys the pulse to the pump. The carb gasket sometimes gets put on upside down and plugs the pulse hole so the pump doesn't work.

A rebuild kit for that Tillitson Carb is probably still available.

 

[gm3d]

More Tilly info

The info in the above post is right on! A few things to add. Change all of the fuel lines, as any air leak, means no fuel delivery. I take the plates and lap them on some VERY fine emery paper and make sure there are no nicks or ridges on the pieces. Put an inline fuel filter in the line, as any speck of dirt or rust will effect the needle and seat. The installation of a primer is a great idea on the old ones (pumper carb). Most Tilly carbs have a brass nipple that is on the flange that mounts to the cylinder. If it doesn't, drill a hole and put one in. Kimpex still makes the carb kits, and they also make a plate that can go between the carb and cylinder for the primer. This makes starting much easier. As the previos post states, check for the hole in the gasket to carb flange. If you put a primer plate in, don't coverthe hole. Some carbs have an external line for the pump. Enjoy you vintage ride!

 

[Gimpster]

Also, after you rebuild the carb and there is still a fuel issue, check the fuel line nipple that comes out of the fuel tank/chassis. I seen quite the number of those old 335's rust the fuel nipple inside and plug it up solid. Hope you are not this unlucky

----- Gimpster -----

 

[touchofgrey]

Thanks for all the good advise. I just took it apart and did a visual inspection. All things seem to look ok. There were a few almost sugar looking crystals on the rubber which has the metal plate on it. The plate is round with a few holes in it, it is the part closest to the needle and seat. I started to clean, but wouldn't you know it all 3 cans of brake clean in the shop are empty, (did I mention I have a teenage son) off to the back doc now, but will pick up some more cleaner and give it another go. Again thanks for the tips. D.

 

[longtrack156]

Careful with the solvents, some will eat those old gaskets.