i just got an old 75 or something olympic 300 from my uncle, my plan is to use it for up keep on my sno-cross track. but the problem i am having with it is that it wont stay running, it starts up first pull runs then starts to die if you give it a hit with the primer it will keep running then start to die again. i replaced the fuel pump with an old one i have, it seems to be getting gas to the carb. im not use to these old tilly carbs. I have a few mikuni carbs around how hard is it to rig one of those on it and jet it right? or does anyone have any idea on how to fix my carb on it?

Mess around with the jetting. Sounds like your low jet could be too rich or too lean. Those old Tilly carb are very finiky and require constant adjustment. Get it running and adjust the low so it idles good. You may have to adjust the idle a little higher too. Once you have your low set, adjust the high.


Good Luck!

D

Buy a kit and rebuild it. Last year, I rebuilt my first Tilly and it wasn't hard at all.

I had the same problem at the first of the season. The needle valve was stuck. I sprayed some wd40 in the intake. there is a little hole in the middle of the carb on the bottom. That is what i sprayed it into. if that doesn't fix it you will probably have to pull it a part and buy the diaphrams to rebuild it. make sure you don't loose the little needle. hope this helps.
sincerely
Donnie Freeze
p.s. make sure you soak the carb in gas to clean out the ports.