Yamaha Malta 3.5hp problems

[All_at_Sea]

I've taken this to bits three times now and it still runs like a dog! (a three legged one with a limp)

Stripped and cleaned the carb, cleared the jets, cleaned the fuel, 100:1 mix checked, spark plug correct make, what else can l do!!!

The rich/lean screw doesen't seem to do anything so l'm not sure if this is the problem, however the whole engines smells of petrol and seems to burn a lot. The actual problem isn't with starting or idling, there is no real power when opened up, just chugs along very unevenly.

Please help before l consign this to the deep (ecologically of course).

 

[Boatman]

I seem to remember that in some of those engines there was a carb jet problem that seemed to appear in some engines causing exactly the problems you have.

Your best bet is talk to the Yamaha agent and see if he knows about it, I am sure it was a fairly common problem

 

[All_at_Sea]

Thanks Boatman l'll give them a call

 

[m1taylor]

Sounds like you have done the correct things re the fuel. There is an outside chance that the problem may not be the carb itself - if your head gasket was faulty, or some other loss of compression, then it will run badly regardless of how clean the carb is. Worth checking - have you removed the Head recently or taken anything else apart?

 

[All_at_Sea]

Not yet, good point though, is it easy to do?

 

[Boathook]

Check the filter in the fuel tap. I had similar problems with my malta and the filter was blocked solid.

 

[All_at_Sea]

How large is the filter - is it in the tap assembly, and is it accessible, or do you simply wash this clean?