94' Suzuki dt 115 no power when under load

[Neversosure]

The motor I have runs good at idle, when you run up the throttle in neut she climbs to 6000 rpm. Stick her in gear and won't climb past 2500 rpm. I looked at the other fellows post about his 115 and he had the same symptons as I do. I am frustrated with this thing help!!!!!!!!!!<br /><br />Matt

 

[Neversosure]

Re: 94' Suzuki dt 115 no power when under load

I was just out in the garage, the oil reset switch on the side of the motor is itsupposed to be a open circuit or a closed circuit? I put my ohm meter on the two leads going into the switch I got nothing, but when I press the switch in and out I get some continuity. I read on the forum here, that if the switch is activated it will cut the rpm down to 3000. But what I need to know is.... what position is the switch supposed to be in when all things are normal.open or closed?<br /><br />Matt K

 

[rodbolt]

Re: 94' Suzuki dt 115 no power when under load

hello<br /> before we jump into suzuki electronics how long did the motor sit since the last time it ran ok? most suzuki problems are fuel. the electrics rarly fail. the reset switch is just a pushbutton switch to manually relese a low oil alarm condition. do you have any abnormal indicators on the monitor?<br /> and quit revving it like that in nuetral<br /> if all ya want is RPM then toss the prop in the creek. no load speed is irrelevant and if your not carefull you will get a nice look at the engine internals.<br /> good luck and keep posting

 

[Neversosure]

Re: 94' Suzuki dt 115 no power when under load

I didn't actually rev it to 6 grand!!!!!!! But it will rev up in neutrol. I tested the oil flow switch and it was ok. Then I tested the TPS with the 9 volt battery and all that stuff.Here is what I found..... the book says you are to have 0.45 to 0.48 with the throttle closed, I had 0.10 volts now that I found that was wrong the book says you can adjust it, so I got my trusty "Non magnetic" screw driver out (was a piece of brass that I fabricated into a flat head screw driver).I couldn't get the volts to fall into spec's so I tried the open throttle test the book says 2.6 to 2.8 volts at open throttle. I had 1.80 wich is not right!!! So I adjusted the TPS for wide open voltage and all I could get was 1.95 volts. So I put it all back together and started it up, It ran great for a minute then went right back to the way it was IE: nothing above 3000 rpm it would sutter and miss etc..<br /><br />I am going to order a TPS and try that I feel that it is bad according to the book.<br />I will keep you posted. If anyone has anything to add to this it would greatly be appreciated.<br /><br />Matt K

 

[rodbolt]

Re: 94' Suzuki dt 115 no power when under load

hello<br /> the TPS on that engine controls ignition timing. if it gets a bad signal or low voltage it will fail to tell the IC module what the throttle angle is and timing will not advance properly.<br /> use a test wheel or a dyno and check timing at WOT it should be within specs. also check that the flywheel gear counting coil is correctly mounted. it does not control timing advance but does set the base for the advance to begin from. the TPS controls timing advance<br />good luck and keep posting

 

[DJ]

Re: 94' Suzuki dt 115 no power when under load

Neversosure,<br /><br />I have to agree with rodbolt. Any 2-stroke engine will wind up in nuetral, no matter how many cylinders aren't working.<br /><br />The DT-140/115 have sensative carburetors. I had to clean mine (DT-140) every year, no matter how I treated to fuel/winterized, etc.

 

[Neversosure]

Re: 94' Suzuki dt 115 no power when under load

Thanks for tips guys!!!!!!! Keep em coming!!!!!<br /><br />I am betting on the TPS, in another post I believe the author was jim owens on iboats here, and he said his TPS winded up being the problem and he "shorted" the two TPS leads together and it ran fine. But I am not sure about "shorting" anything together lol!!! I am going to wait for the new TPS to get here.But today I will check the timing and the tooth counter today.<br /><br />Thanks again ,<br />Matt K

 

[Neversosure]

Re: 94' Suzuki dt 115 no power when under load

OK!!!!, Here's the scoop..... After further reveiw and alot of hours last night and this morning, I narrowed the problem down to the oil flow sensor, weird because it checked out earlier. I put the boat in the water and ran it, and diconnected all the sensors. She ran fine, I put each one back on till the problem came back. Here the flow sensor was causing my dilemma. I want to thank the forims for all the info I got...(RE:... Mixing a small tank of 50:1 as a precaution before running the motor).I am cleaning the oil lines and the tank and should be my problem. I also have a little bit' of mid range surge, I am going to place that on carbs!! I think a little b-12 and a good cleaning will take care of that.<br /><br />But all in all, this is my first Suzuki engine,and what a learning experience!!! All she wanted to do was run today!!!! I ran her up amd trimmed her out she gave me 43+ MPH and I ran out of lake!!! She still had more to give me. I am very pleased, all the posts about the Suzuki electronics being solid is correct!!! Well I am off to clean those oil lines and carbs. I will post back let you all know of any improvement.<br /><br />Thanks again,<br />Matt K

 

[DJ]

Re: 94' Suzuki dt 115 no power when under load

Matt,<br /><br />Good job!<br /><br />Pay special attention to those carbs, a thorough dismantling and cleaning is in order. My DT-140 would also surge, midrange, when they were plugging up.