Is this vaporlock

[galentreble]

I have a 2004 DF 115.Engine cuts off when I am running at slow or fast speeds only when it is seriously hot and humid.It will throw you in the windshield that quick.Put it in neutral and it starts up but I have to prime the bulb and then it works fine.I failed to mention that this only happens after engine has been shut off and then I start it up again an hour later.The dealer tech says this is common and there is nothing that can be done about this.He claim this is vaporlock.I havent found this problem here yet.Can any body help me and give some suggestions.

[nelbur]

It does sound like the vapor lock problem. Suzuki is quite familiar with it. They have installed an in line electric fuel pump on some in warranty motors, which I understand has fixed the problem. It seems like the low pressure pump on the engine can not handle the vapor. It is possible that a new on engine low pressure pump would solve your problem, but it is a known problem on fairly new motors. I also have the problem on my '05 DF 140.

If you start up the engine after sitting for a while, and pump the bulb to firm before you accelerate, I don't believe you will have the problem. Of course, you should not have to do this, but it is much easier than the run around many have had with their dealer. If you could find out from your dealer which electric fuel pump Suzuki used on engines under warranty, you, I, and others could install the fix ourselves. I assume they must have used a low pressure version of an electric pump to avoid overwhelming the needle and seat in the vapor separation chamber, since the pressures of the electric pump and the on engine low pressure pump should be additive.

[galentreble]

Thanks for the info.I will try to prime bulb like you said and check into either buying or hopefully getting help from suzuki.You would think this would have been a recall.

[catacom225]

Fuel lock

First thing i would check is fuel pressure, Aprox=255kpa 36psi
residual fuel pressure, Aprox= 200kpa 28psi

Inspect Fuel Vapour seperator/High pressure fuel pump [behind manifold],suction filter,fuel pressure regulator needle valve & seat
Sometimes the FVS can become dirty and cause fuel problems

[galentreble]

Good advice.I will pass this info on to my suzuki mechanic

[jaysonbarn]

First thing i would check is fuel pressure, Aprox=255kpa 36psi
residual fuel pressure, Aprox= 200kpa 28psi

Inspect Fuel Vapour seperator/High pressure fuel pump [behind manifold],suction filter,fuel pressure regulator needle valve & seat
Sometimes the FVS can become dirty and cause fuel problems

You seem to have a good experience on it with exact figures. From now onwards I am going to ping you for my probs.