70 hp 4 stroke rough idle

[little speedy]

I have a 2002 suzuki 70hp 4 stroke, hte engine idles rough and when you go past idle it dies.
I have replaced all the filters and fuel lines and have drained the vapor seperator.
After I drain the seperator it will run great for about 10 minutes than goes back to rough idle and hard to start than dies when you accelerate.
Any help would be great.

 

[little speedy]

Re: 70 hp 4 stroke rough idle

Could the rough idle and stalling when going into gear be the thermostat?
I haved pumped the ball and this does not seem to have any affect on the condition.
Any ideas

 

[reeldutch]

Re: 70 hp 4 stroke rough idle

when you drained the vst was there water in the gas?
if so your high pressure fuel pump could be on its way out.
also might be dirt in the vst/fuel rail/injectors.

put a high pressure fuel gauge between the hp fuel filter and the fuel rail.
it should be around 35/40 psi (depending on your gauge) and consistand.
psi should not drop to much if it does your hp pump is the problem.

 

[little speedy]

Re: 70 hp 4 stroke rough idle

There was no water when I drained the VST.
It runs great when you first start it but once it gets warm the idle will become rough and it will die when it goes into gear.
I can use the choke to increase the rpm's then go directly into gear and it runs fine once in gear.
It is just the transition from idle into gear.
I will install a gauge on the fuel line and check that.
Thanks

 

[buck99]

Re: 70 hp 4 stroke rough idle

There was no water when I drained the VST.
It runs great when you first start it but once it gets warm the idle will become rough and it will die when it goes into gear.
I can use the choke to increase the rpm's then go directly into gear and it runs fine once in gear.
It is just the transition from idle into gear.
I will install a gauge on the fuel line and check that.
Thanks

I had a similar problem. I replaced the IAC Valve, no improvement; replaced the low pressure fuel filter, no improvement; replaced the high pressure fuel filter and dumped the old gas and replaced with fresh gas, it now runs great.

I still have the 31 indication (no buzzer), do you know how to reset the monitor/tachometer?