if you've bothered to read the entire thread.. you can already see what has been mentioned.
PS. if you think a carb rebuild is expensive.. you are doing something wrong.
basic kits are well under 20$
intividual parts, which can be had from many dealers, are even less. you can cut your own gaskets if you know the gasket paper thickness.
thus. a rebuild can be done virtually FREE if your seats and shaft packings are good.. IE.. just breaking down to clean .. all you need is a gasket set.
a sheet of g-paper can make 5 small ms carbs.. or 4 big ones.
Sure there are people that give advice on machines they know nothing about. I wish they didn't.
confuses the issue when someone walks up and yels out a guess.. then has to ask how the fuel system is even set up.
kinda casts doubt on the guess.
the probably cause of the problem, I believe, has been covered to death here... already.
Yes Sir Captain! Err, wait, that's total b.s. There's a lot of people here who are familiar with their machines who give terrible advice. An engine that cuts out at higher rpms isn't exclusive to 8N's.
Being the expert you are, why not have him check the simple and least expensive things before sending him on the expensive road of a carburetor rebuild or replace? Even you state he has a fuel problem?
