Yamaha Power Loss Under Load

[Paul J Hill]

Hi everyone, I own a 84 60hp Yamaha 2 Stroke that is losing power under load.The motor starts fine,idle's fine,and rev's fine when on the muffs.But when underload on the water it will run at full throttle for about 30 seconds until it loses power and almost cuts out,unless you backoff the throttle and let it idle for a while, then away it will go again for another 30sec's then the situation repeats. I have rebuilt all 3 carbs and checked the fuel pump diaphragm for hole's. Have also just replaced head and exhaust cover gaskets and carried out full decoke,new plugs,thermostat,3 ignition coils and a CDI,also the head was refinished and checked for warpage before it was replaced. Please can someone help as this problem is driving me NUTS !!!

 

[Ray Neudecker]

Re: Yamaha Power Loss Under Load

You might want to try running with a seperate hose and tank. Still sounds like a fuel restriction problem.

 

[jafa]

Re: Yamaha Power Loss Under Load

Tank venting ok ?

 

[Paul J Hill]

Re: Yamaha Power Loss Under Load

Thanks Guy's I will Try Both and let you know how i got on

 

[Paul J Hill]

Re: Yamaha Power Loss Under Load

Originally posted by Sparky 67:<br /> Thanks Guy's I will Try Both and let you know how i got on

Thanks Guy's Problem SOLVED, Ran a seperate tank direct to fuel pump and guess what !!!! No powerloss. Worked my way back one thing at a time and Found some crap in the fuel filter housing.