Loss of power 1999 Suzuki DT 140 EFI

[mlm1977]

I just purchased a boat with a 1999 suzuki dt 140 efi. Motor has about 125 hours on it. First couple of times I took it out it ran great. Next time not so good it started bogging down. I brought it back home and found that around the priming bulb it was leaking fuel or sucking air. Replaced the line and the next time I took it out it ran great. Now back in the same place, took it out a couple of days ago and problem is worse had to come back to ramp about 7 miles per hour, no power almost like it is starving for fuel. Also water discharge out of the hole is steady but when you throttle up stream starts jumping everywhere. Never quits pumping water. Have blown the line out and cleaned the pee hole out and it still does it. Any advice will be greatly appreciated. Thank you

 

[mlm1977]

Re: Loss of power 1999 Suzuki DT 140 EFI

I just purchased a boat with a 1999 suzuki dt 140 efi. Motor has about 125 hours on it. First couple of times I took it out it ran great. Next time not so good it started bogging down. I brought it back home and found that around the priming bulb it was leaking fuel or sucking air. Replaced the line and the next time I took it out it ran great. Now back in the same place, took it out a couple of days ago and problem is worse had to come back to ramp about 7 miles per hour, no power almost like it is starving for fuel. Also water discharge out of the hole is steady but when you throttle up stream starts jumping everywhere. Never quits pumping water. Have blown the line out and cleaned the pee hole out and it still does it. Any advice will be greatly appreciated. Thank you

Any one got any advice?

 

[cousinabe]

Re: Loss of power 1999 Suzuki DT 140 EFI

what maint have you done so far?
filters, water pump, etc
sounds like you have a fuel restriction issue.
have you gone through the fuel system and all filters?

fig 14, part 1
http://store.brownspoint.com/dt140/1408601.asp

more detailed info would be helpful.

 

[reeldutch]

Re: Loss of power 1999 Suzuki DT 140 EFI

before doing anything check the compression.

these motors dont like running lean at all.

if compression is fine do a cylinder drop test while the engine is failing so you can figure out wich cylinder(s) are not contributing.

fuel pressure needs to be a constant 35 psi min.

 

[mlm1977]

Re: Loss of power 1999 Suzuki DT 140 EFI

Thank you both. I have tightened or replaced all fuel lines I found to be loose. I have cleaned the fuel filter, replaced spark plugs. Now when you start the motor it runs fine until it burns all the gas you pumped in and then dies, like the fuel pump isnt working. Does this sound like a fuel pump problem or something to do with fuel injectors?

 

[zbail]

Re: Loss of power 1999 Suzuki DT 140 EFI

I am having a similar issue. What did you ever find to be the problem?

 

[HubertLARSONNEUR]

Re: Loss of power 1999 Suzuki DT 140 EFI

I am having a similar issue. What did you ever find to be the problem?

Hi i have a similar issue, my engine is a dt140 suzuki two strokes from 1999.
I can go to full speed but after a couple of minutes the engine is like running out of fuel, if i use the bulb i can maintain it but not for long, i will have then to lower the accelerator to the min and wait a minute before being able to do it again.
if i stay at 3000 the engine looks like working fine for quite long, sometimes doing the same also at that speed.
I changed the filters and the diaphragm of the pump, tried with an another clean tank and a new line (no change).
Talking to people around i don't get any clear answer, if anyone had the same issue and found a solution please let us know.
best regards

H.L

 

[JB]

Re: Loss of power 1999 Suzuki DT 140 EFI

Hubert: This is a three year old, dead thread.

Please start your own thread.

 

[zbail]

Re: Loss of power 1999 Suzuki DT 140 EFI

Try this. If you changed the fuel filter, and the fuel strainer cup screen on the side of the motor, and are sure the electric fuel pump is on....take off the fuel and oil supply lines line going to/from the fuel vapor separator (FVS), the carb bowl looking thing in front of the motor. two bolts will remove the FVS. Inside the line that goes from the diaphram pump to the FVS, there is a small cone shaped filter that sits inside the nipple that that hose connects on to. many times there is buildup in that filter and it will restrict the fuel flow going into the FVS. take off the bowl and check the needle valve that sits on top of the float, like a carborator bowl. look inside to be sure it is clear. Many times the fuel diaphram breaks apart or the fuel lines deteriorates (with the new gas) and small pieces of plastic/rubber lodge into the cone filter or into the needle valve. this stops the flow of fuel into the fuel/oil mixing bowl or out to the electric fuel pump. I found a small piece of plastic in mine. Dang Gremlins......

There are two sides of fuel for this motor. There is the low pressure side to the FVS and then the high pressure to the the injectors. the low side is volume, the high side is pressure. you do not have volume, if you run out of fuel.

I have a flow scan on my boat and at 2000 rpms you are using about 3gph, at 3000 rpms it is 5gph, at 4000 it jumps to 8gph and WOT its like 12gph. 2.5 MPG.

http://store.brownspoint.com/dt140/fig014-1408601.asp for a schematic.

there are also filter screens on the fuel injectors, but its not likely to be those.

 

[zbail]

Re: Loss of power 1999 Suzuki DT 140 EFI

The old info in the thread does help people understand the repair process. Its a 1999 motor not a 2009. I cant even find a Suzuki mechanic that knows anything about these motors. A new thread hides the thought process for the new poster.

Hey its your forum, just my two cents.