'93 dt150ss

[stumpy]

Need a little help here guys. I will try and keep it as short as i can. A couple months back my motor would not get get my boat up on plane. At that time it seemed to me that the fuel line was loosing prime. well I replaced all fuel lines and primer bulb and fuel lines in the motor. Nothing! what would happen is the motor would idle perfect and it would run in gear at idle perfect. Once you would get up on plane it would run great for about a 100 yards and then loose power. the motor would come back down and idle fine. when trying to get back up it would just act line it was bogging down. Shut the motor off and reprime the line and the same song and dance. Took it to my suzuki mechanic and he said it was the fuel pumps. HE replaced diaphragm in both pumps as well as finding broken check valves. Now when running the boat it would run for several minutes and then begin to loose power and act as if it was a not getting enough fuel.

I took the boat back and told them it was still having the same problem. It would run a lot further however once it started it would repeat itself every time. They got the motor back and went through it again and stated that he found the cone filter was blocked pretty good and they also replaced the high pressure fuel filter as good measure. Put the boat back in the water and though I was good. The boat ran for about 15-20 min and then all of a sudden it reared its ugly face again. I could bring the boat down off plane and it would idle fine. I would try and put it back up and it would just plow and seem as it wasn't getting fuel again. If I shut the motor off and reprime the line it would do fine for a couple of minutes and then again. I also put a remote tank on it with no help. called the mechanic back and he wasn't sure. HE did mention something about a fuel regulator. what do you guys think. I really don't want to keep taking the boat back again and again and spending a bunch of money and not fixing it. I wanted to see what ideas you guys had.
Thanks
Stumpy ( sorry for the long rant)

[keakar]

you have a blocked or restricted vent for the gas tank or sometimes the fuel line connector fitting on the motor gets clogged up or sticks and doesn't open all the way so you don't have enough gas for faster operation.

its definitely a fuel starvation issue, if the primer bulb isn't soft or sucked it when it happens I would clean and check or replace the motors fuel fitting first

[stumpy]

the vent lines are clear. that was the very first thing that i looked at. I also checked the bulb as this was happing and the bulb did not get sucked together. So i ruled the vent out. as far as the fuel fitting are you speaking of the one that goes from the outside fuel line into the motor cowl. Now the boat runs at WOT for serval minutes before I begin to have problem. It does not occur at start up every time.

[stumpy]

Well I returned to the shop today and we got no where. I offered to the guys that I was more than willing to stay around and give them a hand at figuring this problem out. After all who would say no to free labor for a day. We started today by checking fuel lines again, and fuel pressure. my mechanic scratched his head a little when I turned on the key and the pressure gauge shot up initially to around 80 psi and then leaked down to about 35 psi. It remained at 35 psi for some time until we disconnected the gauge. we also took a look at the fuel pressure regulator. It seemed to be okay as best we could tell. We where able to rob another off a parts motor and put it on to try it. HE was also wondering if there was a problem with the lift pump begin that the initial pressure shot up to 80 psi. we replaced the pressure regulator but we didn't have a lift pump to put on. went to the water and it ran flawlessly for a right good while then all of a sudden my problem was back. i trouble shot it a little more and when the boat would begin to loose power i would bring it off plane and try and reprime the bulb. the line was primarily already primed so i would only get about one pump. If i took the boat off plane and shut it down and waited some time, It would run just fine for a couple more minutes.
Anyway I went back to the shop and told this to them and now we are looking into an electrical/computer issue. He is going to look into it a little further It has got us both pissed off so now we have to figure it out. Anything that you guys can think of please let me know. Any ideas would be gratefully beneficial

[stumpy]

I have been trying to do a little more research. How about the possibility of the fuel pump regulator and not the fuel pressure regulator. Would it be possible that after running for a few minutes that the lift pump would begin to act up and now work correctly and when the motor is shut down it kind of resets itself for a short period before it does it again. please I am in need of any ideas that you guys may have. I am almost at the point of giving up and moving on to something else. The only problem is I know that this a good motor and i hate giving up too!

[stumpy]

Hey guys i wanted to bring this back to the top. Went back to the shop the other day and the mechanic dug a little deeper. He began to think that it could be and ignition problem. We swapped ignition control box and it seemed to run great. Put it in the water and ran perfect for about 20min. Ran it yesterday during a fishing tournament and did great running from place to place and then about 4 hours into my day i began to have the same problem once again. Atleast this time i had somebody in the boat to help me with it. When i began to loose power we checked the primer ball and it still had a prime. As it bogged down and came off plane we began to squeeze the ball just to see and it did not help It would run between 2000-2500 rpm. Again if i stopped and shut the motor off and let it sit for a few seconds and started it back it would run. Sometimes it would run a very short distance or it would run for several minutes. a couple of times i would let it loose power and keep the throttle all the way down until it would completely shut off. I would then check the primer and it was slightly soft however it still had a decent prime. I feel like now and can rule out an electrical problem and back to the fuel starvation issue. Is it too much fuel or not enough. Please if anybody has any ideas let me know. I am getting pretty desperate to get this thing running right. I really don't want to give up

[Solarman]

stumpy it sounds like fuel to me.

Read a log from someone that found his little plastic check valves had lodged/partially blocked his float needle valve causing his problems?
Not sure about your situation.

[keakar]

what you descriped could also be an ignition coil going out. they get hot and stop making spark then they cool off and work again. is there a possibility when it happens you are running with one cylinder not firing?

they can run fairly smooth on three cylinders but not make much power

[stumpy]

there is a good chance. I guess my next question would be if it is an ignition coil how would i go about finding which one it is or just look at replacing all of them

[stumpy]

If It where a sensor of some kind i should be getting some sort of alarm right?

[keakar]

to test the ignition coil you would unplug one while its happening and see if it has an effect. it might run ok on 3 cylinders but not on two, it would be noticeably rough on two cylinders. go through all of them and if you unplug one and notice no difference then that's the one not firing.

once you check this you need to find out why so see if its got power and if so then the coil itself is bad. if it has power test it with a spare plug stuck in the coil and make sure the threaded p[art is touching a solid ground or it can shock the poop out of you and see if it fires, if so its the plug that's bad. I use a jumper cable to be sure in case of a bad connection I don't want to get zapped lol.

if you aren't getting power to the coil itself, then that could be a bad ECM that is dropping power to it. the ECM is basically an electronic ignition telling the plugs when to fire

[stumpy]

Well I did a little looking further. The shop stated that they found all the peices of the broken check valve. Before I starting checking ignition coils I decided to take apart the vapor seperator. Well I found a small piece of a check valve stuck in the needle valve on the seperator. Hopefully that is my problem I will see if it isn't them on to the ignition coils thanks for everyone's help. I really appreciate

[Wizzzo]

Starving for fuel

I had the same problem with a 91 Evinrude 300. It was a restriction in the fuel lines to the carbs. I brought it to several mechanics and none of them fixed it. They just threw parts at the problem. I ended up fixing it myself. It could be a number of things. Start by checking fuel pressure and go from there.

[keakar]

Well I did a little looking further. The shop stated that they found all the peices of the broken check valve. Before I starting checking ignition coils I decided to take apart the vapor seperator. Well I found a small piece of a check valve stuck in the needle valve on the seperator. Hopefully that is my problem I will see if it isn't them on to the ignition coils thanks for everyone's help. I really appreciate

where the heck is your fuel filters? there should have been two of them before the vapor separator so you should replace or reinstall those. they are needed as you just found out. also check your low pressure fuel pump and check the diaphrams are still in good condition and clean it of any trash

[stumpy]

What I found was a piece of the broken check valve that is in the fuel pump. There is no filter between the fuel pump and vapor seperator there fore it was stuck in the needle valve. When the fuel pumps where worked on we thought all pieces where accounted for. Obviously not