95 dt150 help please

[nerd4242]

Ok guys since you never heard from DK let me jump in here and if your still out there maybe you can continue where he left off. I am having the Identical problem he was having . I have rebuilt low end fuel pumps , replaced high pressure fuel pump, high pressure fuel filter , low pressure fuel filter, all plugs. I havent taken the vst apart yet but I will this weekend. The boat ran great up until right before last winter. When it did start having this problem it would eventually pickup and run normally but now it will not "kick in" and run past 2000 rpms . No codes and motor doesnt run ruff or misfire. The motor runs strong all the way to 2000 rpms and then after that no matter how much throttle I give it there is no change Every now and then it with jump like its going to take off but then it goes right back to where it is now 2000 rpms. I havent checked the vst or the injectors yet but will either this weekend or next. Thanks for all your help. I sure thought that i would of had the answer by the time I got to the end of this thread I was for sure going to have the answer but then DK never finished his trouble shooting. This thread is so old no one may even still be around or remember but this is the exact problem my boat is having. I have a 95 DT150 efi. Thanks in advance if you are still out there and want to continue where DK left off.
mike

[Solarman]

Aqua, dk did get his motor running. He then took it for a few test runs. Said it ran better than ever. However, he hasn't elaborated on what actually happened. But I believe he over tach'ed (over revved) and lost compression the motor, and messed up the lower unit.

He said he bought a used motor to replace it, haven't heard back from him.

[aquamort]

Hows this one turned out Dk?

[Solarman]

Have you checked the distance to flywheel. If not close enough it won't read correctly? Then read the ohms again, the reading should be same in front of a tooth, the reading should change in an open space (between teeth).

If reading on a tooth fluctuates still, as before, coil is bad.

Post how it's going.

[dkshooter]

gear counter

Ok, I rechecked the gear counter resistance I get 218 consistently between the teeth but when I turn the flywheel (by hand)I get all kinds of numbers ranging from 181 to 261. I assume that this means that the gear counter is bad? could I be doing the test wrong?
thanks guys!

[dkshooter]

sorry

Sorry guys my father passed and things got complicated I have decided that it has to be a sensor problem can anyone tell me how to test all the sensors???

thanks for the patience guys.

[Lucky5]

I did not read this entire post, so this may have been posted already, but I had a similar problem a few months ago. Mine would miss at around 2000 rpms for a few minutes before finally coming out up to a plane, but still missed really bad the entire time the boat was running. I bought a new fuel filter replace the coils and still did not have a answer, so I started tracing wires. What I found was on of the signal wire that goes to the coil was sitting on the head and had melted the wire guarding away causing the coil pack to be grounded out. May could trace some wires and see if you have a similar issue. Hopes this helps.

[aquamort]

Hey DK, hows this one going?

[dkshooter]

thanks for the reply I will start those tests as soon as I can but it is getting dark pretty early after work this time of year!

[Solarman]

dt150, 95, running issues

Dk, if the gear counting coil isn't consistent on either the tooth, or the open space between the teeth then you should replace it.
The timing coils under the flywheel are the same way. If they are not consistent they should also be replaced.

Have you looked over your wiring diagram to see if there are any sensors, or any switches that tie into the timing coil wiring paths that could affect the circuit if they went bad? For example: if a water sensor, or a neutral switch, or maybe the kill switch were tied to the same circuit, and one went bad, it may disable the timing coil for those cylinders, preventing the plugs to fire?

There should be a way to remove the wires (make a diagram of which wire goes into which hole) of the timing coils from the plug (if all three are wired into the same plug). I suggested swapping two timing coils to see if that changed the firing of any of your plugs. Another way to check your timing coils (remove plugs - makes turning flywheel by hand easier) connect your ohm meter to just one coil at a time. Rotate the flywheel several times till your meter reading changes enough times, and note the changes. Do this same test for each of your 3 timing coils. All 3 are the same part number, and should read almost identically. If they do not read the same high, or low reading consistently, then they should be replaced.

Dk, if you find a bad coil, you might want to tape the wires, as all are probably same colors and could get mixed up when removing.
Good luck, let us know what's happening.

[dkshooter]

answers

lots of good questions
Solarman: the gear counter at the last test after adjustment is consistent at 205 when centered on a tooth but when I turn the flywheel the meter jumps, sometimes it goes up and sometimes it goes down cant get an accurate reading it flashes so quickly. your observation on the speeding up on tilt I feel is correct it seems that when you take the load off the motor it revs.
Aquamort:I checked all 3 of the timing coils with a meter and they had the same resistance is there another way to check them? earlier when I was checking for spark there was some activity on 1,3&5 but I have checked all the wiring and could not find any loose wires or corrosion.
thanks again for your time!

[aquamort]

Yep i know they just have one CDI unit. DK from where im sitting i think you need to do as Solarman suggested and make sure your (I believe there are 3) ignition timing coils are all ok. Other then that I would say Ignition Control unit or CDI or as mentioned a bad connection.

Have you tried swapping over the leads from your CDI to the coils from 1 3 or 5 to the other side to see if they the fire up? This would eliminate the coils and HT leads etc and put the problem at the CDI or before it ie timing coils or ICU. Good luck!

[Solarman]

dt150, 95, running issues

Aquamort, the same CDI is used for all cylinders. Don't think it's bad. This is the 2 stroke, and almost all wires are outside the ECU. None that I know of under it. the comment of motor picking up when tilted, I believe a bit high, once it grabbed enough water it pulled itself down. So doesn't appear to be related to tilt.

Dk, I thought you said you adjusted the gear counter and it was reading good? Is it reading consistently, same when you move the teeth in front of it, and is it reading consistently, the same when a space passes in front? If erratic it needs to be replaced. Let us know

[aquamort]

I think Solarman meant plugs from the different coils mixed up? Ive read through and tried catching up on your problem dk. So you now have no spark at all to 1, 3 & 5 ever? Maybe CDI unit or ECU or as mentioned earlier a bad connection? I think there is a main power supply connection behind the ECU on these that can cause troubles if dirty or loose. Just with your earlier comment of the engine picking up when you tilt the engine would suggest that maybe wires are moving and making better contact?

Also were you measuring the gear counter by turning the flywheel with your hand?

[chackett]

dang .. i just sold mine on ebay .. shipped out today