1990 yamaha 25hp 2 stroke firing problem

[Flinnflan33]

I have a 1990 25hp yamaha 2 stroke and it won't fire on the top cylinder. I took it to a shop the compression is good and so are the spark and spark plug. He told me I needed a carb rebuild so I did that and the cylinder ran for a bit but won't fire now. It runs great on the bottom cylinder. Any ideas on what to do next?

 

[woody66912]

Re: 1990 yamaha 25hp 2 stroke firing problem

Pull the top carb off and look at the reed plates, you might have a broke or cracked one.

 

[Flinnflan33]

Re: 1990 yamaha 25hp 2 stroke firing problem

Pull the top carb off and look at the reed plates, you might have a broke or cracked one.

I pulled both carbs off and replaced the gaskets,floats,and needle valves. Not sure what the reed plate is but all components seemed to look good

 

[99yam40]

Re: 1990 yamaha 25hp 2 stroke firing problem

If cleaning helped the 1st time, then more than likely something (passages) plugged up again and need to be cleaned properly and readjusted